Calculate Size of Pole Foundation & Wind Pressure on Pole


  • Calculate Pole foundation size and Wind pressure on Pole for following Details.
  • Tubular Street Light Pole (430V) height is 11 Meter which is in made with three different size of Tubular Pipe.
  • First Part is 2.7 meter height with 140mm diameter,
  • Second part of Pole is 2.7 meter height with 146 mm diameter and
  • Third part of Pole is 5.6 meter height with 194 mm diameter.
  • Weight of Pole is 241 kg and there is no any other Flood Light Fixtures Load on Pole.
  • Total Safety Factor is 2.
  • Wind zone category is 3.
  • The Pole is installed in open terrain with well scattered obstructions having height generally between 1.5 m to 10 m.
  • Foundation of pole is 700mm length, 700mm width and 1.95 meter depth. The Average weight of foundation concrete is 2500 Kg/M3.



 Wind Pressure according to Location:

  • Wind Zone is 3 so Wind Speed as per following Table.
Basic Wind Speed-Vb (As per IS 802-Part1)
Wind Zone  Basic Wind Speed, vb m/s
1 33
2 39
3 44
4 47
5 50
6 55
  • Wind Speed (vb) = 44Mile/Second.
  • Co-efficient Factor (K0)=1.37
  • K0 is a factor to convert 3 seconds peak gust speed into average speed of wind during 10 minutes period at a level of 10 meters above ground. K0 may be taken as 1.375.
  • The Pole is used for 430Vand wind zone is 3 so Risk Co-efficient (K1) as per following Table
Table 2 Risk Coefficient K1 for Different Reliability Levels and Wind Zones (As per IS 802-Part1)
Reliability  Level Wind Zone-1 Wind Zone-2 Wind Zone-3 Wind Zone-4 Wind Zone-5 Wind Zone-6
1 (Up to 400KV) 1 1 1 1 1 1
2 (Above 400KV) 1.08 1.1 1.11 1.12 1.13 1.14
3 (River Crossing) 1.17 1.22 1.25 1.27 1.28 1.3
  • Risk Co-efficient (K1) =1
  • Terrain category (K2) for Open terrain with well scattered obstructions having height generally between 1.5 m to 10 m is 1 as per following Table
  • Terrain category (K2)=1
Terrain Roughness Coefficient, K2 (As per IS 802-Part1)
Terrain Category Category 1 Category 2 Category 3
Exposed open terrain with no obstruction and in which the average height of any object surrounding the structure is less than 1.5 m. Open terrain with well scattered obstructions having height generally between 1.5 m to 10 m. Terrain with numerous
closely spaced obstructions.
Coefficient, K2 1.08 1 0.85
  • Reference Wind Speed (Vr)= Vb / K0.
  • Reference Wind Speed (Vr)= 44 / 1.37 =32 Mile/Second.
  • Design wind Speed (vd)= Vr X K1 X K2.
  • Design wind Speed (vd)= 32 X 1 X 1 =32 Mile/Second.
  • Design Wind Pressure (Pd)=0.6 x vd2
  • Design Wind Pressure (Pd)=0.6 x (32)2 =614.4 N/m2
  • Design Wind Pressure (Pd)=614.4/10 =61.4 Kg/m2

Foundation Detail:

  • Total Weight =Pole Weight +Foundation Weight.
  • Total Weight = 241 +(0.7×0.7×1.95×2500) =2620.75 Kg
  • Stabilizing Moment = Total Weight X (Foundation Length/2)
  • Stabilizing Moment = 2620.75 X (0.7/2) = 920.41 Kg/Meter.

Pole Detail:

  • First Part of Pole (h1) = 2.7 meter
  • Diameter of First Part (d1) =140mm
  • Second Part of Pole (h2) = 2.7 meter
  • Diameter of Second Part (d2) =146mm
  • Third Part of Pole (h3) = 5.6 meter
  • Diameter of Third Part (d3) =194mm .

Wind Pressure on Pole:

  • Overturning Moment due to the wind on 1st Part of the pole=pdxh1xd1x(h1/2+h2+h3)x0.6
  • Overturning Moment due to the wind on 1st Part of the pole=61.4×2.7x(140/1000)x(2.7/2+2.7+5.61)x0.6
  • Overturning Moment due to the wind on 1st Part of the pole=134.47 Kg/meter—I
  • Overturning Moment due to the wind on 2nd Part of the pole=pdxh2xd2x(h2/2+h3)x0.6
  • Overturning Moment due to the wind on 2nd Part of the pole=61.4×2.7x(146/1000)x(2.7/2+5.61)x0.6
  • Overturning Moment due to the wind on 2nd Part of the pole=112.76 Kg/meter.—-II
  • Overturning Moment due to the wind on 3rd Part of the pole=pdxh3xd3x(h3/2)x0.6
  • Overturning Moment due to the wind on 3rd Part of the pole=61.4×5.6x(194/1000)x(5.6/2)x0.6
  • Overturning Moment due to the wind on 3rd Part of the pole=112.14 Kg/meter.—III
  • Total Overturning Moment on Pole due to Wind=134.47+112.76+112.14=359.36 Kg/meter.

 Safety Factor:

  • Calculated Safety Factor= Stabilizing Moment / Total Overturning Moment on Pole.
  • Calculated Safety Factor=920.41/ 359.36 =2.56.
  • For safe Design Calculated Safety Factor > Safety Factor
  • Here Calculated Safety Factor (2.56) > Safety Factor (2) hence
  • Design is OK
  • B : If Calculated Safety Factor < Safety Factor then Change Foundation Size (Length, width or depth)


Calculate Size of Circuit Breaker/ Fuse for Transformer (As per NEC)

  • Calculate Size of Circuit Breaker or Fuse on Primary and Secondary side of Transformer having following Detail
  • Transformer Details(P)= 1000KVA
  • Primary Voltage (Vp)= 11000 Volt
  • Secondary Voltage (Vs)= 430 Volt
  • Transformer Impedance= 5%
  • Transformer Connection = Delta / Star
  • Transformer is in unsupervised condition.


  • Transformer Primary Current (Ip)= P/1.732xVp
  • Transformer Primary Current (Ip)=1000000/1.732×11000=49Amp
  • Transformer Secondary Current (Is)= P/1.732xVs
  • Transformer Secondary Current (Is)=1000000/1.732×430=71Amp
  • AS per NEC 450.3, Max.Rating of C.B or Fuse is following % of its Current according to it’s Primary Voltage,% Impedance and Supervised/Unsupervised Condition.

Max Rating of Over current Protection for Unsupervised Transformer More than 600 Volts (As per NEC)

%Imp Primary secondary
>600Volt >600Volt <600Volt
C.B Fuse C.B Fuse C.B/Fuse
 Up to 6% 600% 300% 300% 250% 125%
More than 6% 400% 300% 250% 225% 125%


Max Rating of Over current Protection for Supervised Transformer More than 600 Volts (As per NEC)

%Imp Primary secondary
>600Volt >600Volt <600Volt
C.B Fuse C.B Fuse C.B/Fuse
 Up to 6% 600% 300% 300% 250% 250%
More than 6% 400% 300% 250% 225% 250%


Max Rating of Over current Protection for Transformers Primary Voltage Less than 600 Volts (As per NEC)

Protection Primary Protection Secondary Protection
Method More than 9A 2A to 9A Less than 2A More than 9A Less than 9A
Primary only protection 125% 167% 300% Not required Not required
Primary and secondary protection 250% 250% 250% 125% 167%


Size of Fuse / Inverse Time C.B as per NEC (Amp)

1 25 60 125 250 600 2000
3 30 70 150 300 700 2500
6 35 80 160 350 800 3000
10 40 90 175 400 1000 4000
15 45 100 200 450 1200 5000
20 50 110 225 500 1600 6000

For Primary Side:

  • Transformer Primary Current (Ip) =52.49Amp and impedance is 5%
  • As per above table in not supervised condition Size of Circuit Breaker= 600% of Primary Current
  • Size of Circuit Breaker = 52.49 x 600% =315Amp
  • If Transformer is in supervised condition then Select Circuit Breaker near that size but if Transformer is in unsupervised condition then Select Circuit Breaker next higher size.
  • Rating of Circuit Breaker =350Amp (Next Higher Size of 300Amp)
  • Size of Fuse = 52.49 x300% =157Amp
  • Rating of Fuse =160Amp (Next Higher Size of 150Amp)

For Secondary Side:

  • Transformer Secondary Current (Is) =1342.70Amp and impedance is 5%
  • As per above table in not supervised condition Size of Circuit Breaker= 125% of Secondary Current
  • Size of Circuit Breaker = 1342.70 x 125% =1678Amp
  • If Transformer is in supervised condition then Select Circuit Breaker near that size but if Transformer is in unsupervised condition then Select Circuit Breaker next higher size.
  • Rating of Circuit Breaker =2000Amp (Next Higher Size of 1600Amp)
  • Size of Fuse = 1342.70 x125% =1678Amp
  • Rating of Fuse =2000Amp (Next Higher Size of 1600Amp)


  • Size of Circuit Breaker on Primary Side=350Amp
  • Size of Fuse on Primary Side=160Amp
  • Size of Circuit Breaker on Secondary Side=2000Amp
  • Size of Fuse on Secondary Side=2000Amp

Selection of Various Types of UPS (Part-2)

(2) Line-Inter active UPS:

  • Working Principle of Line Interactive UPS is same as OFF Line/ stand UPS. It connected directly from mains, switching to battery (via the inverter) in mains Power cut condition.
  • The designing of line interactive UPS is same as OFF Line UPS in addition the design Line Interactive generally includes an automatic voltage regulator (AVR) or a tap-changing transformer. This enhances the regulation of voltage by regulating transformer taps as the input voltage differs.
  • The main difference between an off-line and a line-interactive UPS is that a line-interactive UPS in the stand-by mode has active voltage regulation.
  • Voltage regulation is a significant feature when the conditions of a low voltage exist, otherwise the UPS would transfer to battery and then finally to the load. The usage of more common battery can cause early battery failure.
  • It typically uses either a Ferro resonant transformer or a buck-boost transformer. Both helps to reduce the frequency of transfers to battery, slightly improving efficiency and reducing battery wear.
  • Ferro resonant designs also offer power conditioning and tight voltage regulation, as well as an energy store that can maintain uninterrupted power supply output while the inverter switches on.

Circuit Diagram:


Working Function:

  •  Normal Condition:
  • In Normal Power Condition, power supply will continuously provide to Load with some filtering and voltage regulation circuit.
  • During normal operation, the Line Interactive UPS takes utility power and passes it through a transformer with various tap selections on the output. When utility power is high, the Line Interactive UPS selects a tap to lower (buck) the output voltage. Similarly, when the utility voltage is low, the UPS selects a tap to increase (boost) the output voltage.
  • In Normal Condition Battery is charged continuous charge through Battery Charger
  • Battery charger convert AC power to DC Power and this DC Power charged Battery.
  • Power outage Condition:
  • When utility power fails, the device will start its internal inverter Circuit by Mechanical Switch.
  • Mechanically transfer Switch Transfer from utility power to Battery Power, inverter output.
  • This transfer can take as 2 to 4 ms.


  • small Size
  • Low cost
  • High Efficiency (because less power conversion is when AC input is present).
  • Sine Way Output.
  • Battery life is good compared to OFF Line UPS.
  • Voltage regulation is fair (more than OFF Line UPS but Less than ON Line UPS)
  • EMI/RFI/Noise Rejection is good.
  • Change over Time is 2 to 4 Milliseconds.
  • Lower electricity consumption (less costly to operate).
  • Higher reliability (Lower component count and lower operating temperatures).


  • No isolation between main supply and load
  • Higher Heat Output
  • More Expensive
  • Problematic with power factor corrected loads.


  • For small business.
  • IT Racks, Network Switches, Medical Instrument System where data loss is a serious problem.
  • The line interactive UPS may not be the appropriate choice for installations where AC power is unstable or highly distorted, because battery power will be used too often to keep the UPS output within specifications.


  • UPS in the range of 500VA to 5kVA power.

 (3) ON Line UPS/ Double Conversion UPS

  • It is truly uninterrupted power system (UPS) provide continuous power to load in any condition.
  • Online UPS sometimes called “double conversion” UPS. 
  • Today most users with highly-critical loads are choose online UPS .It is used to protect sensitive equipment and data from mains problems at all times with any extra cost.
  • This UPS have no power transfer switches and therefore no transfer time is existed under the mains power failure. Thus this is truly an uninterrupted system.
  • In Online UPS to maintain the charge of the battery, a battery charging unit is continuously powered from the AC mains.
  • Online UPSs are often called ‘double conversion’ types because incoming power is Firstly converted once AC to DC for the battery and then back Secondly Converter DC to AC before reaching the load which is therefore well-insulated from the mains like an electrical firewall between the incoming power and sensitive electronic equipments. It also control of the output voltage and frequency regardless of the input voltage and frequency.
  • The online UPS continuously filters power through the battery before sending it to your computer.
  • By contrast, online UPS systems draw power through the power conditioning and charging components during normal operation, so the load always receives conditioned power rather than raw mains.

 Circuit Diagram:


Working Function:

  • The designing of this UPS is similar to the Standby UPS, excluding that the primary power source is the inverter instead of the AC main.
  • In this UPS design, any cutoff of input AC Supply does not cause triggering of the transfer switch, because the input AC Supply is charging the backup battery source which delivers power to the o/p inverter. So, during failure of input AC Supply, this UPS operation results in no transfer time.
  • The Transfer switch will automatically transfer the load to mains in case of overload or UPS failure.
  • Normal Condition or Power outage Condition:
  • In Normal Power Condition, power supply will continuously feed from the Inverter, providing conditioned, stabilized sinusoidal voltage.
  • Input Power is filter and regularized by RFI Filter circuit then it is feed to Battery charger which is convert AC Power to DC Power. This DC Power is charged Battery continuously.
  • Battery DC power is converted to AC power by Inverter Circuit.


  • The cost is high compare to other type of UPS.
  • It provides isolation between main supply and load.
  • The output is pure Sign wave.
  • 100% Power Conditioning
  • Constant voltage output.
  • Correction of Input Power Factor
  • Zero transfer time
  • The output voltage is free from distortion due to inverter is always ON.
  • It offers the best power protection, covering any and all types of mains disturbances of supply such as blackout, brownouts, spikes etc are absent in the output.
  • Voltage regulation is better
  • Transfer time is practically zero since inverter is always ON.
  • High Reliability, Units can be connected in parallel redundant configuration.
  • This is the best choice, considering such issues as modularity, ability to work from generator, power factor correction, maintenance, hot swapping, fault clearing, supervising, and communicating.


  • More Expensive
  • Lower Efficiency (Due to inverter is always ON).
  • Higher Heat Output
  • Higher battery TCO
  • Higher operating cost (Supplies power is charge Battery Charger and Inverter both).
  • The wattage of the rectifier is increased since it has to supply power to inverter as well as charge battery


  • It the preferred choice for most business applications.
  • Induction motor drives and similar other motor control applications.
  • Medical equipments and Intensive care units.
  • Electronics manufacturers.
  • Data and call centers.
  • TV stations
  • Production-based manufacturers.


  • From 1 KVA up to 5 MVA.

 Comparison of all types of UPS: 

Comparison of all types of UPS

Features OFFLINE Line-Interactive ON Line
Size of UPS Compact Moderate Big
Cost Cheap Cheaper expensive
Circuit Simplicity Simple Simple Complicated
Transfer Time 4 to 10 millisecond 2 to 4 millisecond 0
Efficiency High Moderate Low
Power Consumption Less Less High
Battery Charging Time More More Less
Battery Life Less Less More
Backup Time Short Short More
Surge Protection
Voltage Regulation Low Better Best
Load Protection Low Better Best
Size Up to 2KVA Up to 5KVA 5 to 500KVA
Reliability Low Better Best
Isolation from Mains Not Available Not Available Available
Noise Reduction Good Good Best
Frequency Stability Not Stable Not Stable Always Stable
Voltage Conditioning Low Better Best
Cost/KVA Low Medium High
Inverter always Operating Yes Yes Yes
Application For Domestic Desktops IT Racks ,Switches ,Distributed Server Data Center, Hospital, Banks
Capacity Up to 800VA 800VA to 1500VA 1000VA to 5000VA

Selection of UPS:

 (1) Size of the UPS (VA & Watts)

  • To decide Power Capacity of the required UPS, we should decide which should be protected and its power consumption in Amps, VA, or Watt.

(2) Back-up time

  • Battery Backup time is the time that batteries are able to back-up operation and feed the load upon failure of utility power. Load consumption and size of UPS batteries decide the back-up time.

(3) Type of the UPS you need

  • UPS’s are divided to three main classes.
  • The Off Line (Stand-by) UPS is the simplest and the least expensive.
  • The Line Interactive type, which overcomes the major disadvantages of  the off-line unit  
  • The On-Line UPS, which provides the best power protection.

(4) Cost:

  • For applications where low cost is critical and it does not matter if backup times are short, an OFF Line UPS is proper solution. However it will not provide adequate protection against spikes or sags from the grid.
  • For applications that require complete isolation from any changes in grid power, such as many medical applications then On Line UPS is the best solution.
  • For applications where power losses due to inefficiencies are less of a concern and eliminating the delay from grid power available to back power is paramount, online UPS is the only solution.
  • For typical applications where conditioning Power is required and very short transfer times from grid to backup power are acceptable and daily energy consumption is a concern, Line Interactive is the preferred solution

 (5) Non-Essential or Critical Load

  • For small office where PC loads is less and small network data protection is required, a small single-phase UPS is often an adequate solution.
  • Most single-phase UPSs use off-line or line-interactive topologies.
  • If the equipment to be protected is critical, an online UPS is the best choice.
  • For loads above 10kVA, the most practical solution is a three-phase UPS, which is most normally with true-online topology. Three-phase online UPSs offer the advantage of providing centralized protection using a single UPS.

 (6) Efficiency:

  • Efficiency is mainly affected on UPS design or operating mode.
  • standby and line-interactive UPSs are more energy efficient than ON Line UPSs because there is no power conversion from AC to DC and then back to AC
  • Efficiency is a factor of UPS size. Larger UPS modules typically have higher energy efficiency than smaller ones, because the support power required for control electronics and auxiliary components becomes a smaller portion of the total capacity of the UPS system.
  • For example, a 500 kW UPS module of a given design would typically be more efficient than a 5 kW UPS module of the same design.

Efficiency of UPS

Capacity Size Standby UPS Line-interactive UPS On Line UPS
5 kW 95 % 96  % 91 %
100 kW  98 % 97 % 98 %
500 kW 99% 98 % 99%

(7) Form Factor:

  • Form factor refers to the the outer-shape of the unit. The Form Factor refers outer shape of UPS.
  • Tower: This is smaller and a stand-alone unit, and It is primarily designed for simple home/office setups.
  • Rack mounted: is larger, designed for a standard rack shelf, and is primarily used for more complex commercial operations.

(8) Noise

  • UPS fan noise may or may not be an issue as per your requirement.
  • Smaller UPS does not normally require a fan for cooling, but larger ones often will.
  • If r work requires perfect silence, make sure your UPS is fan-free.

Resolve Power Quality problem by Type of UPS:

Power Quality Problems & solution by UPS

Power Quality


Description Effect Solved by UPS
Temporary Interruption Accidental total loss of utility power  (Seconds to minutes) Equipment shutdown, loss of  data, file , hard disk and operating system Corruption Off-line – Yes

Line-interactive – Yes

On-line – Yes



Accidental total loss of utility power (minutes to Hour) Equipment shutdown, loss of  data, file , hard disk and operating system Corruption Off-line – No

Line-interactive –No

On-line – Yes



Very short planned or

Accidental power loss.

(Milliseconds to seconds)

Computer and network equipment reboots or hangs, loss of work and data, file Off-line – Maybe

Line-interactive – Maybe

On-line – Yes

Sag or Under-Voltage A decrease in utility

voltage Sags  (Milliseconds to a few seconds)

Shrinking display screens,

Computer hangs or reset,

equipment power supply

damage, loss of data, file

Off-line – No

Line-interactive – Yes

On-line – Yes

Swell or Over-Voltage An increase in Utility

Voltage ( Milliseconds to a

few seconds)

Permanent equipment damage, Computer and network equipment reboots or hangs, loss of data Off-line – No

Line-interactive – Yes

On-line – Yes

Transient, Impulse or


A sudden change in

voltage up to several

hundreds to thousands of

volts (Microseconds)

Network Errors, Burned or

damaged equipment, computer and network

equipment reboots or hangs,

loss of work and data, file

Off-line – Yes

Line-interactive – Yes

On-line – Yes, Higher level of protection.

Noise An unwanted electrical

signal of high frequency

from other equipment

Slow LAN, audible noise in

telephone and audio equipment.


Off-line – No

Line-interactive – No

On-line – Yes

Harmonic Distortion An alteration of the pure

sine wave, due to nonlinear


Causes motors, transformers

and wiring to overheat, lowers operating efficiency

Off-line – No

Line-interactive – No

On-line – Yes


Selection of Various Types of UPS (Part-1)


  • Whenever there is a power cut, electricity supply to Computer, Desktop or other critical appliances is cut off and they stop working. However, if we have a backup supply device such as UPS, we can ensure uninterrupted supply of power to appliances to be not bothered with power cuts.
  • Electrical power supply comes from utility companies is not pure it has different Electrical abnormalities like surges, under voltage, Over Voltage, Voltage dips, voltage spikes, Noise and harmonics. These Electrical abnormalities can cause serious damage to Electronics equipments, Data Systems, Computer or Desktop.
  • To decrease the risk of power supply distortion, UPS systems are frequently integrated in electrical networks. Electronic power supply equipment makers can offer consistent, high-quality power flow for various Electrical / Electronic load gear likes continuous industrial processing applications, medical services, emergency gear, telecommunications, & computerized data systems.
  • Today’s UPS systems usually provide some level of power conditioning and protection against fluctuations in voltage from the grid.


  • UPS means uninterrupted power supply.
  • Uninterruptible power supply (UPS) provides uninterrupted power to the equipment. It means switching time from power cut to battery power is very less hence important equipment like computer, desktop is not switch off and we can lose data.
  • A UPS is a complete system that is consisting of many parts that include batteries, a charge controller, circuitry any transfer switch for switching between the mains and back-up battery, and an inverter. An inverter is needed because the battery can only store DC power and we need to convert that back to AC in order to match the appliances connected in the main power line.
  • UPS= Battery charger + Inverter
  • UPS is nothing but inverter with inbuilt battery charger.
  • UPS is used only to backup your system. If we connect desktop computer on inverter. Inverter takes some seconds to give battery power to equipment hence equipment shutdowns for some second in  any power loss condition and we can lose important data of desktop or computer.
  • Inverter is not suitable for computer backup due to the delay in switching.
  • One of more useful functions of UPS is to provide surge protection so connected devices can be protected from line Surge and does not damage. UPS is also capable of conditioning the power from the lines to provide clean and stable power throughout.

Block Diagram of UPS:

  • The block diagram of this UPS is shown as below


  • The mains power comes to the UPS. The AC is converted to DC and this DC is constantly charging the battery. The output of the battery is fed to the Sine wave inverter and it converts DC to AC and this feeds the equipment. Since power out is always drawn from the battery, there is no time lag when mains switches off, it just stops the battery from being charged and the UPS continues to supply power till the battery runs out.
  • Battery Charger (Rectifier ): To convert AC Power (from Power Grid) to DC Power to charge Battery
  • Battery: To provide DC Power.
  • Inverter: To convert DC Power (from Battery) to AC Power (to power load i.e., electrical and electronic equipment.)
  • Controller: To control functions of Rectifier (Charger) and Inverter. (i.e., when to start or stop charging battery, when to start or stop power from battery to load, how fast to change from Grid Power to Battery Power and so on)

 Type of UPS:

  • The UPS is mainly categorized into three types according to their functions. They are as
  1. Offline Standby (where system or data loss is an inconvenience)
  2. Line-interactive (system or data loss is a serious problem).
  3. Online/Double Conversion (system or data loss is unacceptable).

 (1) OFF Line UPS / Standby UPS:

  • Off-line UPS systems are so-called “OFF Line” because load is normally connected directly to the incoming AC mains. When the incoming AC mains fails or fall below a pre-determined level, then the offline UPS turns on its internal DC-AC inverter circuitry, which is powered from an internal storage battery.
  • For switching purpose UPS consists mechanically / Static switches which immediately connect the load on its DC-AC inverter output under the mains power failure condition. During this changeover there is an inevitable break in power to the load of typically 2 to 10 milliseconds. In practice, however, most loads can ride through this period without any problems.
  • The switching process causes a momentary lapse in power which is dangerous for certain highly-sensitive equipment. This is why technically, the standby UPS is not considered a “true UPS”, as it is not truly “uninterruptible”.
  • The typical lapse time 5ms,is well within tolerance for normal desktop computers

 Circuit Diagram:


 Working Function:

  •  Normal Condition:
  • In Normal Power Condition, power supply will continuously provide to Load with some filtering (typically the same as on a surge protection power strip) from the utility.
  • In Normal Condition Battery is charged continuous charge through Battery Charger
  • Battery charger convert AC power to DC Power and this DC Power charged Battery.
  • Power outage Condition:
  • When utility power fails, the device will start its internal inverter.
  • When utility power fails mechanically transfer Switch Transfer from utility power to Battery Power, inverter output.
  • This transfer can take as 25 ms, which may be too long for some Electronics loads.
  • An Offline UPS will transfer to battery backup during Power cut condition.
  • Off-line systems are generally equipped with spike suppressors, aimed to protect the hardware from high voltages on the utility grid.


  • Cheaper than other type of UPS.
  • Small size.
  • High efficiency.
  • More economical
  • More energy efficient.
  • Lower operating temperature (Due to Fewer parts)
  • Simple Internal control Circuit.
  • Lower initial cost (fewer parts) and lower operating cost (Supplies power is charge only Charger).


  • No isolation between main supply and load
  • No Power Conditioning.
  • Slower Transfer Time.
  • Harmonic distortion is high.
  • UPS output is Quasi square wave.
  • The output contains voltage spikes, brownouts, blackouts.
  • Output is not perfectly reliable.
  • A more serious problem of offline systems is that the load is continuously exposed to spikes, transients and any other abnormalities coming from the power line. This creates a risk of loss or damage to sensitive equipment and data. However in many systems this risk is mitigated but does not eliminated, by spike suppression and radio frequency filtering
  • Most of the short term spikes surges and high frequency harmonics are decayed by means of special filters but transient of mains power existence, like over voltages can harm protected data.


  • small offices, personal home computers and other less critical application
  • Computers, printers, scanners etc.
  • Emergency power supplies, EPABX.


  • Up to 800VA.

Electrical Thumb Rules-Illumination-(Part-19).

Recommended Lighting Levels For Sports Areas  

Bowls 20 lux 50 lux 100 lux 150 lux
Tennis 50 lux 100 lux 150 lux 250 lux
Football 50 lux 100 lux 250 lux 450 lux
Cricket Outfield 50 lux 100 lux 250 lux 450 lux
Cricket Pitch 100 lux 200 lux 400 lux 600 lux
Hockey 50 lux 100 lux 250 lux 350 lux
Swimming 50 lux 100 lux 150 lux 250 lux


Industrial & Office Applications Lux Level

General Engineering Rough Work 160 lux
General Engineering Medium Work 400 lux
General Engineering Fine Work 800 lux
General Engineering Very Fine Work 1600 lux
Inspection Areas Rough Work 160 lux
Inspection Areas Medium Work 320 lux
Inspection Areas Sub Assemblies 400 lux
Inspection Areas Fine Work, electric & high precision mechanical 800 lux
Offices Entrance halls and receptions areas 160 lux
Offices Conference facilities, general offices, typing and filing 500 lux
Offices Computer and business machine operation 630 lux
Offices Drawing Offices 800 lux
Outdoor Areas Mechanical loading 10 lux
Outdoor Areas Manual loading 10 lux
Outdoor Areas Service station forecourts 160 lux
Warehousing Inactive storage 20 lux
Warehousing Loading bays and large materials storage 100 lux
Warehousing Small material storage, packing and dispatch 200 lux


Recommended Lighting Levels

Characteristics of Activity Representative Activity Illuminance (lux)
Interiors rarely used for visual tasks (no perception of detail) Cable tunnels, nighttime sidewalk, parking lots 50
Interiors with minimal demand for visual acuity (limited perception of detail) Corridors, changing rooms, loading bay 100 – 150
Interiors with low demand for visual acuity (some perception of detail) Foyers and entrances, dining rooms, warehouses, restrooms 200
Interior with some demand for visual acuity (frequently occupied spaces) Libraries, sports and assembly halls, teaching spaces, lecture theaters 300
Interior with moderate demand for visual acuity (some low contrast, color judgment tasks) Computer work, reading & writing, general offices, retail shops, kitchens 500
Interior with demand for good visual acuity (good color judgment, inviting interior) Drawing offices, chain stores, general electronics work 750
Interior with demand for superior visual acuity (accurate color judgment & low contrast) Detailed electronics assembly, drafting, cabinet making, supermarkets 1000
Interior with demand for maximum visual acuity (low contrast, optical aids & local lighting will be of advantage) Hand tailoring, precision assembly, detailed drafting, assembly of minute mechanisms 1500 -2000+


Interior Light Levels

Environment Required Light Level
 Storage Area / Plant Room (minimal movement of people) 150 – 200 Lux
 Construction Areas & Loading Bays (minimal perception of detail) 300 – 500 Lux
 Factories & Kitchens (higher perception of detail) 500 – 750 Lux
 Inspection, Welding, And Machinery (demanding work) 750 – 1000 Lux
 Electronics & Textile Production (repetitive detail) 1000 – 1500 Lux
 Technical Offices (accurate detail) 1500 – 3000 Lux
 Jewelers & Goldsmiths (precision detail) 3000 + Lux


Outdoor Light Levels

Environment Required Light Level
Very Bright Summer Day Up To 100,000 Lux
Overcast Summer Day 30,000 – 40,000 Lux
Floodlit Football Match 700 – 16,000 Lux
Shady Room In Daylight 250 – 300 Lux
Night Light On A Building 60 Lux
Night-Time Urban Street 10 Lux
Night-Time Car Park 1 Lux
Security Floodlights 700-1300 Lux
Shed Lights 150-300 Lux
Lamp Posts 120-180 Lux
Landscape Spotlights 120 Lux
Outdoor Path Lighting 100 Lux
Path lighting. 100 Lux
Landscape Lights 100-300 Lux
Garden lights 20 Lux


Illumination Level

Light levels as per IS 1944
Classification of Road Type of road illumination (lux)
Group A1 Important traffic routes carrying fast traffic 30
Group A2 Other main roads carrying mixed traffic, like main city streets, arterial roads, throughways etc 15
Group B1 Secondary roads with considerable traffic like principal local traffic routes, shopping streets etc 8
Group B2 Secondary roads with light traffic Important traffic routes carrying fast traffic 4


Illumination Level

Average Maintained Illuminance
High lux Medium lux Low lux
Major/Major 34 26 18
Major/Collector 29 22 15
Collector/Collector 24 18 12
Collector/Local 21 16 10
Local/Local 18 14 8


Interior Lighting Level

Chartered Institute of Building Services Engineers CIBSE  Part 2 (2002)

Illuminance (lux) Activity Area
100 Casual seeing Corridors, changing rooms, stores
150 Some perception of detail Loading bays, switch rooms, plant rooms
200 Continuously occupied Foyers, entrance halls, dining rooms
300 Visual tasks moderately easy Libraries, sports halls, lecture theatres.
500 Visual tasks moderately difficult General offices, kitchens, laboratories, retail shops.
750 Visual tasks difficult Drawing offices, meat inspection, chain stores.
1000 Visual tasks very difficult General inspection, electronic assembly, paintwork, supermarkets.
1500 Visual tasks extremely difficult Fine work and inspection, precision assembly.
2000 Visual tasks exceptionally difficult Assembly of minute items, finished fabric inspection.


Illumination levels of Switch Yard

AS/NZS 1158.3.1

Switchyard area lighting targets Illuminance (lx)
HV areas including any overhead line road crossings and any access path zone type infrastructure 10
Non-HV areas and general open areas 5
Isolated areas such as back of buildings, corners of switchyards away from HV Equipment 2


Sub Station Light Levels


Environment Required Light Level
CONTROL ROOM / Switch gear Room 300
Battery Room 150
Communication Room 300
Offices/Engineers’ Room/Other Office Room 300
Toilet 100
Outdoor Switchyard area including road 30
Stairs 100
Corridor 100
Road within campus including colony area 30
Maintenance room 150
Any other spot where high level of illumination required 150
Dormitory & ‘C’ type quarters 150
Auxiliary Buildings like Pump room and other houses 150
ACDB- DCDB room/Store / Store Office 150
Conference room 300
Tiffin room/Kitchen 150
GIS Hall 150


Sub Station Light Levels


Environment Required Light Level
Control Room 350
PLCC Room 300
LT Room 150
Charger Room 150
Cable Gallery 150
Heating Plant 100
Battery Room 100
Computer Room 300
Entrance lobby 150
Corridor and landing 150
Conference and display 300
Rest Room 250
AHU Room 100
DG Set Building 150
Fire Fighting Pump House 150
Switchyard – Main equipment 50
Switchyard – general equipment and balance 30
Street/Road 30


Electrical Thumb Rules-Illumination-(Part-18).

Recommended Lighting Levels

IESNA Lighting Handbook

Type of activity Lighting
Public spaces with dark surroundings

30 Lux

Simple orientation for short temporary visits 50 Lux
Working spaces where visual tasks are only occasionally performed 100 Lux
Performance of visual tasks of high contrast or large scale 300 Lux
Performance of visual tasks of medium contrast or small size 500 Lux
Performance of visual tasks of low contrast or very small size 1000 Lux
Performance of visual tasks near threshold of person’s ability to recognize an image 3000-10000 Lux

                              Industries Recommended Levels of Illumination
Area And Task Lux Level
Paper Manufacturing
Beaters, grinding 30
Finishing, cutting 50
Hand Counting 70
Paper machine reel, inspection 100
Rewinder 150
Warehousing, Storage
Inactive 5
Rough Bulky 10
Medium 20
Fine 50
Clothing Manufacture
Receiving, storing, shipping, winding, measuring 30
Pattern making, trimming 50
Shops, making 100
Textile Mills – Cotton
Opening, mixing, picking 30
Carding and drawing 50
Slubbing, roving, spinning, spooling 50
Beaming and splashing on combo Gray goods 50
Denims 150
Gray goods (hand tuning) 150
Denims (rapid moving) 500
Automatic tying-in 150
Weaving 100
Drawing-in by hand 200
Machine Shops
Rough bench and machine work 50
Medium bench and machine work, ordinary automatic machines, rough grinding medium buffing and polishing 100
Fine bench and machine work, fine automatic machines, medium grinding, fine buffing and polishing 500
Extra-Fine bench and machine work, grinding fine work 1000

                                                Recommended Lighting Levels
                           International Standard Serial Number ISSN: 2278-6252
Area/task/ process Illuminance (lux)
Exterior circulating, walkways, stores, main entrances and exit roads, car parking, internal factory roads etc. 20-50
Boiler house, transformer yards, furnace rooms, entrances, corridors, stairs etc. 70-100
Circulation areas in industry, stores and stock rooms, canteen 100-150
Coarse work 200-300
Medium work 300-500
Fine work 500-1500
Very fine minute and precise work 1500-3000
Bale breaking, washing , Stock dyeing, tinting, Mixing, Blowing 200-300
Carding, drawing, roving 300-500
Spinning, doubling, reeling, winding 300-750
Warping 300-400
Sizing 400-500
Heading (drawing in) 750-1000
Weaving (plain gray fabrics) 200-300
Weaving (light colored) 300-750
Weaving (dark colored) 500-1000
Knitting 300-750
Dyeing 200- 450
Calendaring, chemical treatment 300-750
Grey cloth inspection 700-1000
Final inspection 1000-2000

                                              Recommended lighting levels
                                                    IESNA Lighting Handbook
Type of activity Lighting (Lux)
Public spaces with dark surroundings 30
Simple orientation for short temporary visits 50
Working spaces where visual tasks are only occasionally performed 100
Performance of visual tasks of high contrast or large scale 300
Performance of visual tasks of medium contrast or small size 500
Performance of visual tasks of low contrast or very small size 1000
Performance of visual tasks near threshold of person’s ability to recognize an image 3000-10000

                                Illuminance Values for Indoor Activities
                                                TABLE 10.4 IES
Public spaces with dark surroundings large area (lobby space) 20-30-50
Simple orientation for short temporary visits large area (lobby space) 50-75-100
Working spaces where visual tasks are only occasionally performed large area (lobby space) 100-150-200
Performance of visual tasks of high contrast or large size localized tasks 200-300-500
Performance of visual tasks of medium contrast or small size localized tasks 500-750-1000
Performance of visual tasks of low contrast or very small size localized tasks 1000-1500-2000 100
Performance of visual tasks of low contrast  or very small size over a prolonged period extremely difficult visual tasks 2000-3000-5000
Performance of very prolonged and exacting visual tasks extremely difficult visual tasks 5000-7500-10000
Performance of very special visual tasks of extremely low contrast extremely difficult visual tasks 10000-15000-20000

                                                           Lighting levels-Sports
Sports Illumination
National/ international     500 Lux
Regional/Local     200 Lux
Local/Training     75 Lux
National/ international   500 Lux
Regional/Local     300 Lux
Local/Training      200 Lux
National/ international    500 Lux
Regional/Local     200 Lux
Local/Training      100 Lux
National/ international    750 Lux
Regional/Local     500 Lux
Local/Training      300 Lux
Court lighting
Social Play 310 Lux
Club Competition 435 Lux
International 1250 Lux
National/Internal      750 Lux
Regional/Local     500 Lux
Local/Training     200 Lux

                                                           Lighting levels-Sports
                                             Australian Standard  AS 2560.2.6 – 1994
Sport Illumination Level
Baseball (International & National) 1500 lux
Baseball (AAA Standard) 750 lux
 Baseball (Club Competition) 250 lux
Recreational Level 50 lux
Amateur Level (Training) 50 lux
Amateur Level (Competition) 100 lux
Semi-Professional level (Training) 50 lux
Semi-Professional (match Practice) 100 lux
Semi-Professional (Competition) 200 lux
Professional level (Training) 100 lux
Professional level (Match practice) 200 lux
Professional level (Competition) 500 lux
For all sports the minimum for TV coverage. 1500 lux

                        Recommended Lighting Levels For Sports Areas 
Area Type Lux
Archery, indoor
General Area 25
Shooting Zone 50
Target (Vertical) 100
Recreational 300
Supervised Training 400
Club & County 400
National & International 500
Bowls, indoor
Practice 300
Club & County 400
National & International 500
Club & Supervised Training 500
Regional 750
National 1000
International 2000
Special Events 2000
Cricket, indoor
Recreational & Supervised Training 400
Club & County 500
Cycle Racing,
Training 300
Club 500
National & International 750
Equestrian, indoor
Practice & Training, show jumping 400
Practice & Training, Dressage 300
Competition Show Jumping 700
Competition Dressage) 500
Five-A-Side Football, indoor
Recreational & Supervised Training 300
Club & County 400
National & International 500
Handball, indoor
Recreational & Supervised Training 300
Club 400
County & National 500
International 750
Hockey, indoor
Recreational & Supervised Training 300
Club 400
County & National 500
International 750
Ice Rinks, Indoor
Hockey & Figure Skating Training 200
Hockey & Figure Skating Competition 750
Skating, Recreational 100
Lawn Tennis, indoor
Recreational 300
Practice & Club 400
County 500
National & International 750
Lawn Tennis, outdoor
Recreational 200
Club 300
County 400
National & International 500
Martial Arts, indoor
Supervised Training 300
Club 400
National 500
Netball, indoor
Recreational & Supervised Training 300
Club & County 400
National & International 500
Shooting, indoor
Target (Vertical) 1000
Shooting Zone 300
Snooker & Billiards
Recreational & Club 750
 National & International 1000
Recreational & Supervised Training 300
Club & County 400
 indoor National 500
International 750
Swimming, indoors
Recreational 200
Club & County 300
 National 500
 International 10000
 Table Tennis
Recreational 200
Club & County 300
National 500
International 750
Recreational 200
Training, Club & County 300
 National 500
International 750
Weight Training
Supervised Training 400
Sports Halls
Recreational 300
 Club & County 400-500
 National & International 500-750
Televised (vertical/normal to camera) 1000-2000
 Indoor Arenas
Maintenance of Area 100
General Lighting & Training 300
Competition 500
Spectator Viewed Events 900
Televised (vertical/normal to camera) 1000-2000

Electrical Thumb Rules-Illumination-(Part-17).


Lighting levels

Chartered Institution of Building Services Engineers (CIBSE)

Building Lux
Areas common to most buildings
Entrance hall, lobby, waiting room 200
Enquiry desk 500
Corridor, passageway, stairs 100
Atria 50-200
Changing room, cloakroom, lavatory 100
Rest room 150
Canteen, cafeteria, dining room 200
Kitchen 300
Commercial offices  
General offices 500
Computer workstations 300-500
Conference rooms, executive offices 500
Computer and data preparation rooms 500
Filing room 300
Banks and building societies  
Counter, office area 500
Public area 300
Entrance halls 100
Reception, cashiers and porters’ desks 300
Bars, coffee bars, dining rooms, grill rooms, restaurants, lounges 50-200
Cloakrooms, baggage, rooms 100
Bedrooms 50-100
Bathrooms 150
Kitchen 150-300
Small retail outlets 500
Grocery/vegetable stores 500
Showrooms 1000
Covered arcades and malls 500-700
Fashion 500-750
Supermarket 750
Restaurant 200
Bookshop, chemist, jeweler 500
Superstore 1000
Electrical/furniture store 750
Arcades and malls 50-300
Places of public assembly
Cinema and theatre foyer 200
Booking office 300
Auditoria 100-150
Library 150-300
Museum art gallery 50-300
Lecture theatre 300
Church 100-300
School and College  
Computer Room 300
Classroom and Tuition Centre 350
Technical Drawing Room 750
Museum and Science Centre  
General Area and Corridor 150
Common Toilet and Restroom 200
Special Lighting for Paintings 300
Special Lighting for Sculptures 750
Retail Shop and Outlet  
Sales Area and Premises 400
Gift Wrap Station 450
Cash Register Counter 500
Commercial Space and Office  
Lift Lobby 200
Corridor 300
Toilet and Restroom 150
Cafeteria 350
Plant Room (AHU, Genset etc.) 150
Store Room 180
Lift Lobby 200
Corridor 250
Waiting Area and Lobby 300
Common Toilet and Restroom 250
Waiting rooms 200
Counseling Room 200
Breast-Feeding Room 200
Intensive Care Unit 300
High Dependency Unit 300
Isolation Room 300
Isolation Room – Ante Room 300
Delivery Suite – Labor Room 300
Simple examination room 300
Operating Theatre – Air-Lock 300
CSSD/TSSU – Sterilization Area 300
CSSD/TSSU – Packing Area 500
Patient Ward – Room 300
Patient Ward – Toilet 150
Operating theatre 1000
Conference Room 400
Catering Dept – Main Kitchen 400
Catering Dept – Beverage Kitchen 300
Catering Dept – Refuse Holding 150
Nursing Homes
Entrance lobbies 200
Lounges (communal) 300
Kitchens 300
Bathrooms 150
Toilets 100
Corridors 100
Staircases 100
Quiet / rest rooms 100
Dining rooms 200
Stores 100
Hotel and Restaurant  
Lift Lobby 150
Corridor 150
Common Toilet and Restroom 150
Bar 150
Bedroom 200
Conference Room 400
Exhibition Hall 500
Cinema, Concert Hall and Theatre  
Entrance Foyer 200
Auditorium 150
Toilet and Restroom 200
Dress Change 300
Make-Up Room 400
Residential Buildings  
Living Room 200
Dining Room 250
Kitchen 250
Bedroom 180
Bathroom 150


Lighting Levels

Chartered Institution of Building Services Engineers (CIBSE)

Area Illuminance (lux)
Lifts 100
Corridors and stairs 100
Toilets 100
Canteens 300
Mess rooms 150 – 300
Plant rooms 150 – 300
Store rooms 100


Recommended Lighting Levels

Singapore Standards SS 531-1 : 2006 (2013)

Type of area, task or activity Lux
Shipyards & Docks  
Shipyard area, storage areas 20
Short term handling of large units 20
Ship hull cleaning 50
Ship hull painting and welding 100
Mounting of electrical and mechanical components 200
Building Sites  
Clearance, excavation and loading 20
Construction areas, drain pipes mounting, auxiliary and storage tasks 50
Framework element mounting, light reinforcement work, wooden mould and framework mounting, electric piping and cabling 100
Element jointing, electrical machine and pipe mountings 200
Very Low Risk: Storage areas with occasional traffic in industrial outdoor 5
Low Risk: Occasionally used platforms and stairs in petrochemical industries 10
Medium Risk: Pre-Fabrication yards, Vehicle storage, Fuel storage 20
High Risk: Areas with pits / excavations, Valves, compressors area, regularly used staircase and platforms 50
Office Interior  
Filing, copying 300
Writing, reading, Data processing 500
Technical drawings 750
CAD work stations 500
Conf& Meeting rooms 500
Reception desk 300


Recommended Lighting Levels 


Area Lux
General Area
Entrance halls 100
Lounges 200
Circulation area and corridors 100
Stairs, escalators, travelators 150
Loading ramps/bays 150
Canteens 200
Rest rooms 100
Rooms for physical exercise 300
Cloakrooms, washrooms, bathrooms, toilets 200
Sick bay 500
Rooms for medical attention 500
Plant rooms, switch gear rooms 500
Dispatch packing handling areas 300
Control station 150
Agriculture building
Loading and operating of goods handling equipment and machinery 200
Building for livestock 50
Sick animal pens, calving stalls 200
Feed preparation, dairy, utensil washing 200
Preparation and baking 300
Finishing, glazing,decorating 500
Cement, concrete, & bricks industry
Drying 50
Preparation of materials,work on kilns and mixers 200
General machine work 300
Rough forms 300
Ceramics and glass industry
Drying 50
Preparation, general machine work 300
Enameling, rolling, pressing, shaping simple parts, glazing 300
Grinding, engraving, glass polishing, shaping precision parts, manufacture of glass instruments 750
Decorative work 500
Grinding of optical glass, crystal hand grinding and engraving, work on average goods 750
Precision work e.g decorative grinding, hand painting 1000
Manufacture of synthetic stones precious 1500
Chemicals, plastics and rubber industry
Remote operated processing installations 50
Processing installations with limited manual intervention 150
Constantly manned work places in processing installations 300
Precision measuring rooms, laboratories 500
Pharmaceutical production 500
Tire production 500
Color inspection 1000
Cutting, finishing, inspection 750
Electrical industry
Cable and wire manufacture 300
Wending -large coils 300
Wending-medium-sized coils 500
Wending-small Coils 750
Coil impregnating 300
Galvanizing 300
Assembly work-rough e.g. large transformers 300
Assembly work- medium e.g. switchboards 500
Assembly work- fine e.g. telephones 750
Assembly work-precision e.g. measuring equip. 1000
Assembly work-Electronic workshops, testing, adjusting 1500
Prayer Area, Mosques 300
Arrival and departure halls, baggage claim areas 200
Connecting areas, escalators, travelators 150
Information desks, check in desks 500
Customs and passport control desks 500
Waiting areas 200
Luggage store rooms 200
Security check areas 300
Air traffic control tower 500
Air traffic rooms 500
Testing and repair hangars 500
Engine test areas 500
Measuring areas in hangars 500
Platforms and passenger subways (underpasses) 50
Ticket hall and concourse 200
Ticket and luggage offices and counters 300
Waiting rooms 200
Health care premises
Waiting rooms 200
Corridors: during the day 200
Corridors: during the night 50
Day rooms 200
Staff office 500
Staff rooms 300
 Wards-General lighting 100
 Wards-Reading lighting 300
Wards-Simple examination 300
Examination and treatment 1000
Night lighting, observation lighting 5
Bathrooms and toilets for patients 200
Examination room general 500
Ear and eye examination 1000
Reading and Color vision test with vision charts 500
Scanners with image enhancers and television systems 50
Dialysis rooms 500
Dermatology rooms 500
Endoscopy rooms 300
Plaster rooms 500
Medical baths 300
Massage and radiotherapy 300
Pre-operation and recovery rooms 500
Operating theatre 1000
Intensive care- General lighting 100
Intensive care- Simple examinations 300
Intensive care-Examination and treatment 1000
Intensive care– Night watch 20
Dentists- General lighting 500
Dentists- At the patient 1000
Dentists- Operating cavity 5000
Dentists- White teeth matching 5000
Color inspection (laboratories) 1000
Sterilization rooms 300
Disinfection rooms 300
Autopsy rooms and mortuaries 500
Autopsy table and dissecting table 5000
Educational buildings
Play school room 300
Nursery class 300
Nursery craft room 300
Classrooms, tutorial rooms 300
Classroom for evening classes and adults education 500
Lecture hall 500
Black board 500
Demonstration table 500
Art and craft rooms 500
Art rooms in art schools 750
Technical drawing rooms 750
Practical rooms and laboratories 500
Teaching workshop 500
Music practice rooms 300
Computer practice rooms 500
Language laboratory 300
Preparation rooms and workshops 500
Student common rooms and assembly halls 200
Teachers rooms 300
Sports halls, gymnasiums and swimming pools 300
Public car parks (indoor)
In/out ramps 300
In/out ramps (at night)  75
Traffic lanes 75
Parking areas 75
Ticket office 300
Bookshelves 200
Reading area 500
Counters 500
Places of entertainment
Theatres & concert halls 200
Multipurpose halls 300
Practice rooms, dressing rooms 300
Museums (general) 300
Restaurants and hotels
Reception/cashier desk, porters desk 300
Kitchen 500
Restaurant, dining room, function room 200
Self-service restaurant 200
Buffet 300
Conference rooms 500
Corridors 100
Sales area small 300
Sales area large 500
Till area 500
Wrapper table 500


Illuminance values

As per IES

Area Type Lux
Corridors, Passageway 100
Lift 150
Stairs 150
Escalator 150
External Covered Ways 30
Entrance halls, lobbies, waiting rooms 150
Enquiry desk 500
Gate houses 300
Foods stores 150
General 500
Controlled entrance halls or  exit gate 150
Entrance and exit car park 30
Stores, stockyards 30
Industrial covered ways 50
Centre cafeterias, dining room 300
Consultant room, treatment areas 500
Medical stores 100
Rest room 150
Changing locker and cleaner’s room, cloakrooms lavatories 150
Rest rooms 150
Telecommunication board,switchboard rooms 500
Cordless switchboard 300
Apparatus rooms 150
Teteprinter rooms 500
Aircraft engine testing 750
Inspection and repairs (hanger) 500
External apron general 50
Pumps 300
Parking areas (interior) general repairs servicing 30
Greasing, pits washing, polishing 500
Exterior walkways and platforms 50
Exterior stairs and ladders 100
Retort house, oil gas plants, watergas plant purifier, indoor coke 100
Booster and exhauster houses 150
General 1000
Rough work e.g. counting rough Checking of stock parts 300
sub-assemblies 500
Fine work e.g. radio and telecommunication equipment, calibrated scales, precision mechanism, instruments 1000
Very fine work e.g. gauging and inspections of small intricate parts 1500
Minute work e.g. very small instruments 3000
Living rooms general 50
Casual reading 150
Sewing darningsrudies desk and protuged 300
Bedroom general 50
Bed lead kitchen 150
Bathrooms 100
Halls and landings 150
Stairs 100
Workshops 300
Garages 50
Athletics, basketball, bowls, judo 300
Hockey 700
General  Table special lighting 100
Top pool 500
Spectator areas 150
Club recreational 300
Changing rooms showers, lookers rooms 150
Club 300
Recreational 200
Ward unit bed heads general 30
General 150
Nurse station evening 300
Pharmacies dispensing bench 500
Shelves 150
Reception general 300
Enquiry desk 500
Laboratories 500
Operating theatre suits general 400
Operating area 30-50
X-ray department radio diagnostic and rooms fluoroscopy 500
Airport coach and railway station
Reception areas (desk),customs and immigration halls 500
Railway stations booking offices 500
Railway station parcel and left luggage offices counters 300
Circulation area 150
Waiting area 300
Assembly halls general 300
Teaching spaces general 300
Teaching spaces general 300
General where also used for further education 500
Chalkboard 500
Beedlework rooms 500
Laboratories 500
Workshop 300
Gymnasium 300
Music practice rooms 300
Exhibits insensitive to light 300
Light sensitive exhibits 150
Specially light sensitive exhibit 50
Shelves, book stack 150
Reading table 300
Reading rooms, newspaper and magazines 300
Reference libraries 500
Counters 500
Cataloging and sorting 500
Binding 500
Closed book store 100
Theatre and concert halls 100
Cinemas 50
Multipurpose 500
Conventional with counters 500
Conventional with wall display 500
Conventional with wall display 500
Self service 500
Supermarkets 500
Hypermarkets 500
General 500
Executive office 500
Computer rooms 500
Punch card rooms 750
Drawing offices drawing boards 750
Reference table and general 500
Print room 300
General office with mainly clerical task and typing office 500
Deep plan general offices 750
Business machine and typing 750
Filling room 300
Conference rooms 750
Aircraft Industry
Maintenance area 750
Inspection area 1000
Paint Shop 1000
Testing area 750
Instruments assembly 1500
Electrical assembly 1500
Explosives Manufacturing
Furnaces, Boiling Tanks, Driers 200
Mechanical furnaces, mechanical driers, generators 500
Paint Shop
Simple spraying 200
Fine finishing 500
Extra fine finishing 2000
Paint Manufacturing
Processing 200-500
Mix comparison 1000-2000
Electricity generating station
Boilers area 50
Cooling towers 50
Fuel handling 50
Storage tanks 10
Transformer yards 50
Turbine areas 50
Petroleum, Chemical and Petrochemical Industry
Process areas
General process units
Pump rows, valves, manifolds 50
Heat exchangers 30
Maintenance platforms 10
Operating platforms 50
Cooling towers (equipment areas) 50
Furnaces 30
Ladders and stairs (inactive) 10
Ladders and stairs (active) 50
Gauge glassed 50
Instruments (on process units) 50
Compressor house 200
Separators 50
General area 10
Control rooms and houses
Ordinary control house 300
Instrument panel 300
Console 300
Back of panel 100
Central control house 500
Instrument panel 500
Console 500
Back of panel 100
Specialty process units
Electrolytic cell room 50
Electric furnace 50
Conveyors 20
Conveyor transfer points Change house 50
Locker room, shower 100
Lavatory 100
Clock house and entrance gatehouse Card rack and clock area 100
Entrance gate, inspection 150
General 50
Eating 300
Serving area 300
Food preparation 300
General, halls, etc. 100
Garage and firehouse
Storage and minor repairs 100
First aid room 700
Iron and Steel Industry
Open hearth
Stock yard 100
Charging floor, Pouring side , Slag pits 200
Control platforms 300
Mold yard 50
Kilns (operating area) 50
Extruders and mixers 200
Non process areas
Loading, unloading, and cooling
water pump houses
Pump area 50
General control area 150
Control panel 200
Boiler and air compressor plants
Indoor equipments 200
Outdoor equipments 50
Tank fields (where lighting is required)
Ladders and stairs 5
Gauging area 10
Manifold area 5
Loading racks
General area 50
Tank car 100
Tank trucks, loading point 100
Electrical substations and switch yards
Outdoor switch yards 20
General substation outdoor 20
Substation operating aisles 150
General substation indoor 50
Switch racks 50
Plant road lighting (where lighting is Required)
Frequent use (trucking) 4
Infrequent use 2
Plant parking lots Aircraft obstruction lighting 1
Laboratories Qualitative, quantitative and physical test 500
Research, experimental 500
Pilot plant, process and specialty 300
ASTM equipment knock test 300
Glassware, washrooms 300
Fume hoods 300
Stock rooms 150
Warehouse and stock rooms
Indoor bulk storage 50
Outdoor bulk storage 5
Large bin storage 50
Small bin storage 100
Small parts storage 200
Counter tops 300
Repair shop
Large fabrication 200
Bench and machine work 500
Craneway, aisles 150
Small machine 300
Sheet metal 200
Electrical 200
Instrument 300
Hot top 300
Hot top storage 100
Checker cellar 100
Buggy and door repair 300
Stripping yard 200
Scrap stockyard 100
Mixer building 300
Calcining building 100
Skull cracker 100
Rolling mills
Blooming, scabbing, hot strip Hot sheet 300
Cold strip, plate 300
Pipe, rod, tube, wire drawing 500
Merchant and sheared plate 300
Tin plate mills Tinning and galvanizing 500
Cold strip rolling 500
Motor room, machine room Inspection 1000
Black plate, bloom and billet chipping Tin plate and other bright surfaces 2000


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