Impact of Floating Neutral in Power Distribution

Introduction:

  • If The Neutral Conductor opens, Break or Loose at either its source side (Distribution Transformer, Generator or at Load side (Distribution Panel of Consumer), the distribution system’s neutral conductor will “float” or lose its reference ground Point. The floating neutral condition can cause voltages to float to a maximum of its Phase volts RMS relative to ground, subjecting to its unbalancing load Condition.
  •  Floating Neutral conditions in the power network have different impact depending on the type of Supply, Type of installation and Load balancing in the Distribution. Broken Neutral or Loose Neutral would damage to the connected Load or Create hazardous Touch Voltage at equipment body. Here We are trying to understand the Floating Neutral Condition in T-T distribution System.

What is Floating Neutral?

  • If the Star Point of Unbalanced Load is not joined to the Star Point of its  Power Source (Distribution Transformer or Generator) then Phase voltage do not remain same across each phase but its vary according to the Unbalanced of the load.
  • As the Potential of such an isolated Star Point or Neutral Point is always changing and not fixed so it’s called Floating Neutral.

Normal Power Condition & Floating Neutral Condition

             Normal Power Condition:

  • On 3-phase systems there is a tendency for the star-point and Phases to want to ‘balance out’ based on the ratio of leakage on each Phase to Earth. The star-point will remain close to 0V depending on the distribution of the load and subsequent leakage (higher load on a phase usually means higher leakage).
  • Three phase systems may or may not have a neutral wire. A neutral wire allows the three phase system to use a higher voltage while still supporting lower voltage single phase appliances. In high voltage distribution situations it is common not to have a neutral wire as the loads can simply be connected between phases (phase-phase connection).

  • 3 Phase 3 Wire System:
  • Three phases has properties that make it very desirable in electric power systems. Firstly the phase currents tend to cancel one another (summing to zero in the case of a linear balanced load). This makes it possible to eliminate the neutral conductor on some lines. Secondly power transfer into a linear balanced load is constant.
  • 3 Phase 4 Wire System for Mix Load:
  • Most domestic loads are single phase. Generally three phase power either does not enter domestic houses or it is split out at the main distribution board.
  • Kirchhoff’s Current Law states that the signed sum of the currents entering a node is zero. If the neutral point is the node, then, in a balanced system, one phase matches the other two phases, resulting in no current through neutral. Any imbalance of Load will result in a current flow on neutral, so that the sum of zero is maintained.
  • For instance, in a balanced system, current entering the neutral node from one Phase side is considered positive, and the current entering (actually leaving) the neutral node from the other side is considered negative.
  • This gets more complicated in three phase power, because now we have to consider phase angle, but the concept is exactly the same. If we are connected in Star connection with a neutral, then the neutral conductor will have zero current on it only if the three phases have the same current on each. If we do vector analysis on this, adding up sin(x), sin(x+120), and sin(x+240), we get zero.
  • The same thing happens when we are delta connected, without a neutral, but then the imbalance occurs out in the distribution system, beyond the service transformers, because the distribution system is generally a Star Connected.
  • The neutral should never be connected to a ground except at the point at the service where the neutral is initially grounded (At Distribution Transformer). This can set up the ground as a path for current to travel back to the service. Any break in the ground path would then expose a voltage potential. Grounding the neutral in a 3 phase system helps stabilize phase voltages. A non-grounded neutral is sometimes referred to as a “floating neutral” and has a few limited applications.

          Floating Neutral Condition:

  • Power flows in and out of customers’ premises from the distribution network, entering via the Phase and leaving via the neutral. If there is a break in the neutral return path electricity may then travel by a different path. Power flow entering in one Phase returns through remaining two phases. Neutral Point is not at ground Level but it Float up to Line Voltage. This situation can be very dangerous and customers may suffer serious electric shocks if they touch something where electricity is present.

  • Broken neutrals can be difficult to detect and in some instances may not be easily identified. Sometimes broken neutrals can be indicated by flickering lights or tingling taps. If you have flickering lights or tingly taps in your home, you may be at risk of serious injury or even death.

Voltage Measurement between Neutral to Ground:

  • A rule-of-thumb used by many in the industry is that Neutral to ground voltage of 2V or less at the receptacle is okay, while a few volts or more indicates overloading; 5V is seen as the upper limit.
  • Low Reading: If Neutral to ground voltage is low at the receptacle than system is healthy, If It is high, then you still have to determine if the problem is mainly at the branch circuit level, or mainly at the panel level.
  • Neutral to ground voltage exists because of the IR drop of the current traveling through the neutral back to the Neutral to ground bond. If the system is correctly wired, there should be no Neutral to Ground bond except at the source transformer (at what the NEC calls the source of the Separately Derived System, or SDS, which is usually a transformer). Under this situation, the ground conductor should have virtually no current and therefore no IR drop on it. In effect, the ground wire is available as a long test lead back to the Neutral to ground bond.
  • High Reading: A high reading could indicate a shared branch neutral, i.e., a neutral shared between more than one branch circuits. This shared neutral simply increases the opportunities for overloading as well as for one circuit to affect another.
  • Zero Reading: A certain amount of Neutral to ground voltage is normal in a loaded circuit. If the reading is stable at close to 0V. There is a suspect an illegal Neutral to ground bond in the receptacle (often due to lose strands of the neutral touching some ground point) or at the subpanel. Any Neutral to ground bonds other than those at the transformer source (and/or main panel) should be removed to prevent return currents flowing through the ground conductors.

Various Factors which cause Neutral Floating:

  • There are several factors which are identifying as the cause of neutral floating. The impact of Floating Neutral is depend on the position where Neutral is broken

1)    At The Three Phase Distribution Transformer:

  • Neutral failure at transformer is mostly failure of Neutral bushing.
  • The use of Line Tap on transformer bushing is identified as the main cause of Neutral conductor failure at transformer bushing. The Nut on Line Tap gets loose with time due to vibration and temperature difference resulting in hot connection. The conductor start melting and resulting broke off Neutral.
  • Poor workmanship of Installation and technical staff also one of the reasons of Neutral Failure.
  • A broken Neutral on Three phases Transformer will cause the voltage float up to line voltage depending upon the load balancing of the system. This type of Neutral Floating may damage the customer equipment connected to the Supply.
  • Under normal condition current flow from Phase to Load to Load to back to the source (Distribution Transformer). When Neutral is broken current from Red Phase will go back to Blue or Yellow phase resulting Line to Line voltage between Loads.
  • Some customer will experience over voltage while some will experience Low voltage.

2)    Broken Overhead Neutral conductor in LV Line:

  • The impact of broken overhead Neutral conductor at LV overhead distribution will be similar to the broken at transformer.
  • Supply voltage floating up to Line voltage instead of phase Voltage. This type of fault condition may damage customer equipment connected to the supply.

3)    Broken of Service Neutral Conductor:

  • A broken Neutral of service conductor will only result of loss of supply at the customer point. No any damages to customer equipments.

4)    High Earthing Resistance of Neutral at Distribution Transformer:

  • Good Earthing Resistance of Earth Pit of Neutral provide low resistance path for neutral current to drain in earth. High Earthing Resistance may provide high resistance Path for grounding of Neutral at Distribution Transformer.
  • Limit earth resistance sufficiently low to permit adequate fault current for the operation of protective devices in time and to reduce neutral shifting.

5)    Over Loading & Load Unbalancing:

  • Distribution Network Overloading combined with poor load distribution is one of the most reason of Neutral failure.
  • Neutral should be properly designed so that minimum current will be flow in to neutral conductor. Theoretically the current flow in the Neutral is supposed to be zero because of cancellation due to 120 degree phase displacement of phase current.
  • IN= IR<0 + IY<120 + IB<-120.
  • In Overloaded Unbalancing Network lot of current will flow in Neutral which break Neutral at its weakest Point.

6)    Shared neutrals

  • Some buildings are wired so that two or three phases share a single neutral. The original idea was to duplicate on the branch circuit level the four wire (three phases and a neutral) wiring of panel boards. Theoretically, only the unbalanced current will return on the neutral. This allows one neutral to do the work for three phases. This wiring shortcut quickly became a dead-end with the growth of single-phase non-linear loads. The problem is that zero sequence current
  • From nonlinear loads, primarily third harmonic, will add up arithmetically and return on the neutral. In addition to being a potential safety problem because of overheating of an undersized neutral, the extra neutral current creates a higher Neutral to ground voltage. This Neutral to ground voltage subtracts from the Line to Neutral voltage available to the load. If you’re starting to feel that shared neutrals are one of the worst ideas that ever got translated to copper.

7)    Poor workmanship & Maintenance :

  • Normally LV network are mostly not given attention by the Maintenance Staff. Loose or inadequate tightening of Neutral conductor will effect on continuity of Neutral which may cause floating of Neutral.

 How to detect Floating Neutral Condition in Panel:

  • Let us Take one Example to understand Neutral Floating Condition.We have a Transformer which Secondary is star connected, Phase to neutral = 240V and Phase to phase = 440V.

    Condition (1): Neutral is not Floating

  • Whether the Neutral is grounded the voltages remain the same 240V between phase & Neutral and 440V between phases. The Neutral is not Floating.

 Condition (2): Neutral is  Floating

  • All Appliances are connected: If the Neutral wire for a circuit becomes disconnected from the household’s main power supply panel while the Phase wire for the circuit still remains connected to the panel and the circuit has appliances plugged into the socket outlets. In that situation, if you put a voltage Tester with a neon lamp onto the Neutral wire it will glow just as if it was Live, because it is being fed with a very small current coming from the Phase supply via the plugged-in appliance(s) to the Neutral wire.
  • All Appliances are Disconnected: If you unplug all appliances, lights and whatever else may be connected to the circuit, the Neutral will no longer seem to be Live because there is no longer any path from it to the Phase supply.
  • Phase to Phase Voltage: The meter indicates 440V AC. (No any Effect on 3 Phase Load)
  • Phase to Neutral Voltage: The meter indicates 110V AC to 330V AC.
  • Neutral to Ground Voltage: The meter indicates 110V.
  • Phase to Ground Voltage: The meter indicates 120V.
  • This is because the neutral is “floats” above ground potential (110V + 120V = 230VAC). As a result the output is isolated from system ground and the full output of 230V is referenced between line and neutral with no ground connection.
  • If suddenly disconnect the Neutral from the transformer Neutral but kept the loading circuits as they are, Then Load side Neutral becomes Floating since the equipment that are connected between Phase to Neutral will become between Phase to Phase ( R to Y,Y to B), and since they are not of the same ratings, the artificial resulting neutral will be floating, such that the voltages present at the different equipments will no longer be 240V but somewhere between 0 (not exactly) and the 440 V (also not exactly). Meaning that on one line Phase to Phase, some will have less than 240V and some will have higher up to near 415. All depends on the impedance of each connected item.
  • In an unbalance system, if the neutral is disconnected from the source, the neutral becomes floating neutral and it is shifted to a position so that it is closer to the phase with higher loads and away from the phase with smaller load. Let us assume an unbalance 3 phase system has 3 KW load in R-phase, 2 KW load in Y-phase and 1 KW load in B-phase. If the neutral of this system is disconnected from the main, the floating neutral will be closer to R-phase and away from B-phase. So, the loads with B-phase will experience more voltage than usual, while the loads in R-phase will experience less voltage. Loads in Y-phase will experience almost same voltage. The neutral disconnect for an unbalanced system is dangerous to the loads. Because of the higher or lower voltages, the equipment is most likely to be damaged.
  • Here we observe that Neutral Floating condition does not impact on 3 Phase Load but It impacts  only 1 Phase Load only

How to Eliminate Neutral Floating:

  • There are Some Point needs to be consider to prevent of Neutral Floating.

a)    Use 4 Pole Breaker/ELCB/RCBO in Distribution Panel:

  • A floating neutral can be a serious problem. Suppose we have a breaker panel with 3 Pole Breaker for Three Phase and Bus bar for Neutral for 3 Phase inputs and a neutral (Here we have not used 4 Pole Breaker). The voltage between each Phase is 440 and the voltage between each Phase and the neutral is 230. We have single breakers feeding loads that require 230Volts. These 230Volt loads have one line fed by the breaker and a neutral.
  •  Now suppose the Neutral gets loose or oxidized or somehow disconnected in the panel or maybe even out where the power comes from. The 440Volt loads will be unaffected however the 230V loads can be in serious trouble. With this Floating neutral condition you will discover that one of the two lines will go from 230Volts up to 340 or 350 and the other line will go down to 110 or 120 volts. Half of your 230Volt equipment will go up in high due to overvoltage and the other half will not function due to a low voltage condition. So, be careful with floating neutrals.
  • Simply use ELCB, RCBO or 4 Pole Circuit Breaker as income in the 3ph supply system since if neutral opens it will trip the complete supply without damaging to the system.

b)   Using Voltage Stabilizer:

  • Whenever neutral fails in three phase system, the connected loads will get connected between phases owing to floating neutral. Hence depending on load resistance across these phases, the voltage keeps varying between 230V to 400V.A suitable servo stabilizer with wide input voltage range with high & low cutoff may help in protecting the equipments.

c)  Good workmanship & Maintenance :

  • Give higher Priority on Maintenance of  LV network  . Tight or apply adequate Torque for  tightening of Neutral conductor in LV system

Conclusion:

  • A Floating Neutral (Disconnected Neutral) fault condition is VERY UNSAFE because If Appliance is not working  and someone who does not know about the Neutral Floating could easily touch the Neutral wire to find out why appliances does not work when they are plugged into a circuit and get a bad shock. Single phase Appliances are design to work its normal Phase Voltage when they get Line Voltage Appliances may Damage .Disconnected Neutral fault is a very unsafe condition and should be corrected at the earliest possible by troubleshooting of the exact wires to check and then connect properly.
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About Jignesh.Parmar
Jignesh Parmar has completed his B.E(Electrical) from Gujarat University. He has more than 11 years experience in Power Transmission-Power Distribution-Electrical energy theft detection-Electrical Maintenance-Electrical Projects(Planning-Designing-coordination-Execution). He is Presently associate with one of the leading business group as a Assistant Manager at Ahmedabad,India. He is Freelancer Programmer of Advance Excel and design useful Excel Sheets of Electrical Engineering as per IS,NEC,IEC,IEEE codes. He is technical Author for "Electrical Mirror" and "Electrical India" Magazines. He is Technical Blogger and Familiar with English, Hindi, Gujarati, French languages. He wants to Share his experience & knowledge and help technical enthusiasts to find suitable solutions and updating themselves on various Engineering Topics.

56 Responses to Impact of Floating Neutral in Power Distribution

  1. shyam says:

    Sir,
    i am shyam kumar.k, working as sub-station in-charge in BHEL-trichy. The information provided by you is very worthy and is very useful for every electrical engineer.

    your great effort is to be definitely appreciated.

    Thanks & Regards,
    Shyam kumar.k

    • Andrew HL says:

      Mr.Jignesh,

      “How to eliminate neutral floating – Simply use ELCB, RCBO or 4 Pole Circuit Breaker as income in the 3ph supply system since if neutral opens it will trip the complete supply without damaging to the system.” – I do not see how using a 4-pole breaker will help at all, specifically, how will a “neutral open” trip the 4-pole breaker unless an overload (or short circuit) occurs as a result. I would appreciate your clarification. Best regards.

  2. Arun Banerjee says:

    Dear Mr Jignesh,
    All the information provided by you are extremely useful for any electrical engineer.
    I convey my heartfelt good wishes to you.
    Regards,
    Arun Banerjee

  3. P.Prabhakaran says:

    All the information provided by you are extremely useful for any electrical engineer.

    Regards
    P.Prabhakaran

  4. niranjankalle@gmail.com says:

    Dear Mr.Jignesh,

    Its very good information and are very much usefull.

    Thanks&Regards,
    Niranjan

  5. sharath says:

    nice informations .it helps to clear some doubts .what we can do if the leakage in neautral please give the informations .

  6. akash says:

    sir,
    Its too good to having a all information on every point of electrical engineering weather it is a theoretical or practical ,,its really great thank you so much.

  7. Senthil says:

    Very good, relevant information

  8. Abig says:

    nice information ! thanks
    from Ethiopia

  9. callistus ozoke says:

    Dear J Parmar,
    Your entire submission on the impact of loose earthing is a master piece.How would a resident electrical engineer know when the has occurred?

  10. dear sir,
    Thanks fr the valuable data. would u provide the clearances for the power cables in trays & related standards.

  11. John says:

    Good article. Systems in the United States are typically single phase 120/240V systems with 2 energized phases and a common neutral. A classic symptom of a disconnected neutral is incandescent lights going alternately dim and bright in the home. This symptom should also be present in the system described above. Appliances operating on 110 Volts will tend to go to 220V at times when large loads on other phases operate. Ask the user if lights are going bright and then dim. If they answer “yes,” suspect a disconnected or poorly connected neutral.

    • Bill says:

      I purchased a Chinese made diesel generator; Kaiser KDE-12-STA; a 10KW unit. During a recent power outage I hooked up the unit to the house, for the first time. Started seeing strange things, random voltage both high and low and damaged several items before getting it shut down. During trouble shooting, I discovered that the 3 prong female receiver plug at the 240 volt spot ONLY had two wire feeding it, both were hot, they are 120v each. There is NO neutral wire at all, the prong is empty, no wire attached to it; Therefore I do not have a neutral feed going into my sub-panel from the generator. I have been told that this is the reason why I am getting crazy voltage readings in the house. I was also told that If I could trace the neutral wire, that is on the 120v spots, to the source and then bring a wire from the source out to the 240v spot on the generator, that this would solve the problem. Others I said that it will make no difference and that I can not use this generator to supply a house with the 120/240 supply. Your help would be much appreciated. I found you by following a thread about floating neutral problems.
      Thank you,
      Bill

  12. Lala says:

    working on my masters project on London Distribution Network. been trying to figure out how the 3-phase 1-phase to neutral line works in under distribution. this is reallly useful! thanks!

    • Basavaraj A says:

      Dear Mr.Jignesh,

      Its very good information and are very much usefull.

      Thanks&Regards,
      Basavaraj Avali

  13. YuXiang says:

    Dear Sir,
    A 600VA single phase isolation step up transformer 100V to 120V, primary side feed with 100VAC and Earth cable connected to panel chassis. The secondary side 120V is supplied to a
    controller’s L and N terminal; the E terminal of controller is tied to panel chassis earth. When i measured the L and N terminal with respect to the chassis earth, it has 75.5V and 41.5V respectively. Is it what we call floating neutral voltage? I think this not healthy to the controller and with some electrical noise will cause the controller haywire too. What’s corrective method? Please advise.

    • g.raman says:

      thanks for presenting a valuable information with illustration.we appreciate your effort .thanks
      g.raman

  14. kareena shah says:

    THANKS while designing these notes are really helpful

  15. Mangey ram says:

    Dear sir,
    Thanks for all useful information about the floating neutral.I am also an electrical engineer in UP state Govt. and i found a solution of my problems relatively neutral and earth, from your great experience.

    Regards,
    Mangey ram

  16. Hi! I understand this is sort of off-topic but I needed to ask.
    Does managing a well-established website such as yours take a
    lot of work? I am brand new to blogging however I do write in my
    diary on a daily basis. I’d like to start a blog so I will be able to share my experience and feelings online. Please let me know if you have any kind of suggestions or tips for new aspiring bloggers. Thankyou!

  17. rahul says:

    thanx a lot for this information its be benefitial for my academic

  18. Praveen says:

    Hi JP,firstly thanks for the info.we have installed ELCB/rcbo & 4P breakers even then we had an issue with the neutral,the safety devices did not trip resulting in a huge loss.
    can you suggest other measures to prevent neutral floating /Breakage/isolating.

  19. Sibaji Pattanaik says:

    It is really true and very very important to check the Neutral condition in any house hold application to avoid Electrical Hazard.

  20. yogesh Dohaiya says:

    in 3phase 4four system total load of computers coneccted in all 3phases.Fault occur in this system is neutral carry more current than phases(e.g. ph1-20A,ph2-21A,ph3-31A and N-56A why?piease give anser.

  21. website says:

    Thank you, I have recently been looking for information about this subject for a long
    time and yours is the greatest I’ve found out so far. But, what in regards to the bottom line? Are you sure in regards to the source?

  22. Gaurav Goyal says:

    Very nice info, recently I had a neutral disconnected situation at my home and a few equipments like both microwaves and a tablet charger broke. Still do not understand why there were isolated incidents as there were several things plugged in.

  23. Rama says:

    Thank you sir ,very interesting, and useful information, thanks

  24. this is really very informative. can u pls suggest me some book on improving my understanding on power quality specially the problem of voltage between neutral and Ground.

  25. Hafiz says:

    Thanks for the lengthy explanation. My system 33 & 11kV with Neutral Earthing Resistance network. Can I use a Neutral Displacement \ Voltage Displacement relay to detect missing neutral?

  26. ishtiyaq ahmed says:

    can u plz post a note on testing of electrical equipments like trnsfrmr, HT/LT switchgear, motor, breaker, CT and VT.

  27. Shaun thomas says:

    Great information even though I deal with theses issues on a daily bases. One question on a 3 phase+neutral system: if the phases are imbalanced and a high current occurs on the neutral, will this have any implication on the electrical running costs?
    Regards
    Shaun T

  28. Mahaveer Bhandari says:

    Good information even for new graduates.
    One observation- A similar neutral break contion occurs, when the ground buried supply cable develops a fault (insulation failure or any short between RYBN and shield of the armoured cable. This has been noticed by me on several occassions when severe unbalance conditions of volatage occur at the user end and damage the equipment. The 4 wire ELCB at the entry point of utility is a good suggestion to protect the connected load.

  29. Miller the Killer says:

    What damage will a floating neutral do to 120V appliances and/or 240V appliances (AC units, hot water heaters,etc.)? What about any wire damage or long term effects on household appliances? I had a floating natural for several months in a vacant house that was being renovated and the contractor burned up some tools and the power bills were over $500 per month. One leg at the meter was reading +/- 120V, but the other one was spiking to over 175V. The neutral/ground on all the outlets, the water hose bibs outside, etc. were spiking to over 70V. The lights in the house were literally going up and down all night. The power company already changed out the transformer that submerged last year under salt water, but that did not fix the problem. They are coming back tomorrow and the electrician has determined it is an outside problem (“floating neutral”) and assumes it is a problem with the burred wires. Thank you.

  30. steven says:

    first, thanks for your valuable teaching, will buy you a drink next time we meet..
    you said in Condition (2): Neutral is Floating, Phase to Ground Voltage: The meter indicates 120V (at the consumer power socket). But I understand that in TT distribution System, the ground at the consumer power socket is the one go down directly to the earth mass by grounding rod, which also located at consumer end. If the ground line at the supply transformer end is in proper order condition (not broken ) and both the earth electrodes resistance are good, then I think the phase to ground voltage measured at consumer socket should be near to 230V..

  31. anthony says:

    at the gererating plant, how you test the neutral braided bus bar ?

  32. Mukesh Tyagi says:

    Thanx a lot ,it very usefull.Looking for more usefull knowledge.

  33. lupupa peria says:

    mine its nt a comment bt a question,wat happens to a domestic house which has a floasting neutral and at the same time it has good earthing system? Wil it have impact on neutral?

  34. Miller the Killer says:

    The readings on one leg at the bus bar was ranging between 40V to over 170V depending on the power load. The house at night looked like someone was getting electrocuted as the lights were going up and down all night until the problem was fixed.

  35. Smith says:

    Thanks a lot for Useful Information

  36. prasada says:

    hi sir thanks for your valuable information
    i have doubt regarding “PT” secondary voltage is fluctuating at 11 kv phase to neutral side.we are getting 1.7v difference in the single phase.even though the earth resistance is 0.1 ohms.why it is getting like that can u explain me please

  37. M.K.Madhavan says:

    Dear Sir,
    Your explanation regarding Floating Neutral turns my attention towards the reasons why the voltage variation in each phase to neutral is happening. Thanks.

  38. Teguh says:

    Appreciated so much, thank you for your sharing. very helpful

  39. shivaraj says:

    Dear Mr.Jignesh,

    Its very good information and are very much usefull. for me i am very small home electrical technician
    i am seen neutral floating problem iam still can’t salved can you help me to solve this problem
    and how remove the short between neutral phase (like that i put the tester neutral and phase both line are showing live and any one line removed from the circuit than showing ok ) and some time when swithed the light bulb bulb liting dimly i checked voltage that time showing 120v neutral to phase and that line one bulb liting normaly and one bulb liting dimly any help for this solve this problem

    Thanks&Regards,

    shivaraj from Bangalore

  40. K.V.RAO says:

    Nice write up on floating neutral. My sincere appreciation to Mr. Jignesh

  41. Richard Keakantse says:

    Richard says
    Ah! first thanks for giving out that knowledge. But still i don’t see how a four pole breaker will help during neutral floating problem . Could you explain more.

    regard
    Richard

  42. Tofiq Azad says:

    The contents of the article are very useful for electrical engineers.

  43. How to decrease the Neutral to earth voltage in a distribution system.

    • Tauseef says:

      i think,1st you have to balance your load on 3 phases,and 2nd you should ground your neutral near to distribution transformer..

  44. Dear Mr.Jignesh,

    Hi sir thanks for your valuable informatio Its very good information and are very much usefull i am Asst Executive Engineer in PWD Andhra Pradesh.I am facing floating neutral problem in some of our Govt Buildings in those building when we measure voltage between Neutral to Earth it is nearly 15v. So how to decrease the voltage between neutral to earth so kindly give solution for this problem.

    Thanks&Regards,

    shivaraj from Bangalore

    • Tauseef says:

      i think your neutral is grounded too far and facing resistance in neutral conductor.,and these 15v are subtracting from phases.your load is also imbalanced..

  45. Dionne says:

    Thanks for sharing your knollege

  46. Tauseef says:

    Dear Mr jignesh!
    aslam o alaekm!

    the info provided by you is very good and usefull,i m electrical superviser in a local organization….i was very confused about neutral and grounding.now i m cleared about it..thanks for ur great information.
    may God bless you,

  47. Jay Kulkarni says:

    Dear Mr. Jignesh,

    Thank you very much for the information.

    Pl tell me why neutral CT is required at distribution transformer?

    Kindly clarify it to me.

    Regards,

    Jay Kulkarni

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