Method for Installation of DB or Panel-(Part-1)


Purpose:  

  • This method of statement describe the procedure for safely installation and testing of DB and LV Panel as per contract specification and as per the standard Practice and Code.

General Equipment & Tools:

  • The equipment that will be engaged for Installation of Panel ,D.B will be
  • Tool Box with Screwdriver, Pliers, Spanner , Hammer
  • Drilling Machine with various Bits , Grinding & Cutting Machine
  • Electrical Tester , Continuity Tester ,Multi Meter , Earth Tester , IR Tester
  • Wire Cutter , Blower ,Crimping Tools
  • Knockout punch and Flat File
  • Marker, Measuring tape, Level gauge / Spirit level.
  • Ladder / Scaffolding / Mobile scaffold
  • Chain Block and Pipe Wrench
  • Portable Lights
  • Removable Barricades

Storage & Material Handling:.

  • Suitable lockable storage shall be made on Site.
  • The storage area must be free from dust and Water leakages / seepages.
  • The DB, Panel and Accessories shall be unloaded with care in designated area of the Store to avoid any damages and against the effects of weather or any construction activities of Site.
  • The Material will be stacked / unload in the site store on a proper stand on wooden loft on a flat surface at a sufficient height from Ground.
  • Materials shall be stored in a place free of water and adequately covered to avoid any kind of damages.
  • Proper protection should be given to the material by means of covering the material with Tarpaulin sheet etc.
  • If they are dispatch in packs or pallets, each pack of pallet shall be lifted individually with suitable lifting equipment.
  • The material shall be transported / Shifted in their original packing to Site location.

Inspection of Materials:

  • Inspection of Materials:
  • Check the reference of delivered material against approved submittal and purchase order.
  • Check The Material according to its Type, Size, Make
  • Physical Damages Inspection:
  • In case of any damages observed during inspection, the concern report will be issued and Material shall be returned to the supplier for replacement.

Sequence of Installation Works:

(1) Shifting of Panel on Site

  • Prior to commencement of Panel installation works, areas and access shall be checked and confirmed by safety officer, that they are in a suitable Condition for installation works.
  • Decide appropriate Size of Crain / Hydra according to weight of Panel.
  • Panel shall be carefully unloaded or shifted to the site by using Crane/Hydra or by sufficient manpower and moved to a defined installation location.
  • Remove the packing and ensure that the panel is free from transportation damages
  • Check The shop drawings, Material submittals, Method statement, ITP & HIRA are approved,
  • Ensure all contents are available inside the panel.
  • Ensure control wiring identification shall be correctly done.
  • Megger shall be used having a valid calibration certificate.

1

(2) Installation of Panel:

  • Marking of Panel Position:
  • For floor mounted panel, the exact location of the panel and fixing holes to be marked on the concrete plinth for the installation.

2

  • Remove the Factory packing and ensure that the LT panel is free from transportation damages

3

  • Install the panel in proper alignment and fix properly.

4

  • To secure panel base to the floor using M12 anchor bolts.
  • Access around the panel to be checked for future maintenance as per regulations.
  • Ensure the services contains water is away from the panel or properly protected against any accidental leakages.
  • Incoming and outgoing cables shall be marked/identified as per approved shop drawing.
  • Mark the fixing position of the DB’s support as per approved shop drawing and coordinate with other equipment and services.
  • After marking are then drilled according to the selected sizes of anchor bolts to appropriate depth as per approved shop drawing.
  • Locknuts on the anchor bolts will ensure a permanent fixing of the DB support to the wall/slab.
  • After installation of DB supports, installing position of the DB as per approved shop drawing.
  • Ensure that painting of the wall is completed prior to marking and mounting of DB.
  • All DBs wall mounting and floor mounted arrangement will be in accordance with approved shop drawings and the approved material submittal.
  • If there is more than one DB to be installed at the same location, they shall be installed side by side and clearance shall be maintained as per approved shop drawing.
  • The height of Distribution Board shall be maintained as per approved shop drawing so that easy access for termination of cables and other maintenance work can be carried out.
  • Check the position according to the approved shop drawings.
  • Check & ensure adequate space is available for maintenance
  • After installation, the panel shall be properly cleaned and protected to prevent dust & contamination.
  • Before beginning installation in any area, examine all adjoining works in that area should be completed. Installation shall not proceed in that area until such conditions are corrected by the contractor.
  • Fix all equipment independently of wiring system. Use cadmium of zinc electroplated bolts, nuts, washers and screw.
  • Mount single DB at 1800mm from finish floor level to top of equipment, unless shown otherwise on drawing / schedules.
  • Ensures that clearance in front of switchgear is not less than 1m, or as indicated.
  • For flush installation, DB’s all conductors shall terminate behind the board in an adaptable box.
  • For surface mounting, trunking shall be fixed between the board and ceiling or floor level, or conduit run directly into Trunking which prevent correct installation of the Trunking lid.
  • The panel with plywood will be pushed towards the trolleys inside substation Room
  • When the panel reaches on the trolleys inside the substation room. Push the panel to the location where need to install .
  • To set up the chain block support to fix the chain block.
  • When the panel reaches the actual installed location, lifting-up of panel by using of chain block. Lift the panel on the panel base
  • If Panel is in section wise
  • Position the first section panel on the fixing channel & check the leveling by using the level bar & adjusting with liners.
  • To secure panel to the panel base using M12 anchor bolts.
  • To rack in the correct breaker & PT to the correct panel.
  • Proceed in the same manner for the second sections.
  • Position the second section next to the first panel.
  • Secure the second section to the panel base using two M12 anchor bolts
  • Interconnect & fasten the two section units together.
  • Proceed in the same manner for the other sections.

(3) Non Electrical checks before Charging Panel:

 (a) General Checking of Panel:

  • Confirm label/marking to ensure that is the Panel is correct according to the approved shop drawings.
  • All components (Circuit Breakers, Relays, Voltmeter and Ammeter) of the panel shall be verified against the approved panel / Technical drawing as per correct in Numbers, rating & size.
  • Ensure all contents are available inside DB.
  • Check that it is not possible to come into contact with energized equipment when working on the system.
  • If there are any Correction or modification than Check All internal connections/modification will be carried out by the Manufacturer.
  • Check the main bus bar and auxiliary circuits (control, monitoring, alarm, and fault) for continuity.
  • All breakers (incoming/outgoing) shall be in “OFF” position and to be locked to prevent mishandling

(b) Visual Checking of Panel:

  • Ensure the absence of all foreign bodies inside the switchboard.
  • Identifications labels of approved engraved type nameplate shall be fixed on DB.
  • Check the compliance with the protection index (leak tightness of the functional units, various sealing points, etc.).
  • Check the Continuity of grounding bus bar to the main earthing system.
  • Check that the panel hinged doors are connected to the frame by earthing braids.
  • Adequate earth continuity shall be made between the various components.
  • Check the door locks for correct operation
  • Check the connections for conformity with the reference drawings.
  • Check Continuity of Main, Auxiliary, Eathing and Neutral Busbar with respect to incomer and outgoing Circuits.
  • Check the connections for conformity with the reference drawings and their tightness.
  • Number terminals, cables and component parts to correspond with manufacturer have certified drawings.
  • Ensure that vents are clear and filters are in place. Screens covering ventilation openings should be in place to prevent entry of rodents or small animals.
  • Check the outer appearance (absence of any traces of shocks, peeling paint) -carry out any touch-ups if needed.

(c) Mechanical Checking of C.B:

  • Check for correct racking in and Out for circuit breaker and check :
  • That it is impossible to rack in a circuit breaker in the closed position.
  • That it is impossible to close a circuit breaker not correctly racked in.
  • That it is impossible to rack out a circuit breaker is in ON condition.

(d) Tightness of all Connection of Switchgear.

  • Fully tight all Bolted electrical connections of Electrical Switch gear of Panel.
  • Loose bolted electrical connections can lead to higher energy consumption and eventual equipment failure if not properly addressed.
  • Loose control, Power wires can lead to spark, over heat which turns in to catastrophic failure.
  • Check that all wiring connections are tight and that wiring is secure to prevent damage during routine operation of moving parts, especially when removing draw-out circuit breakers or opening and closing cubicle doors.
  • Gently tug on control wires to ensure a tight connection or use a screwdriver to gently verify torque on the connection. Infrared scans are also very effective for finding loose wires in control circuits.
  • Tighten all the connections as required

(d) General Wiring Checks for Switchgear

  • Wire inserted in the Panel will be cross-checked for existing circuit number done and final ferruling shall be done as approved shop drawing. 
  • Wire in Panel shall be used cable tie and dress with bunching of the phase-neutral and earth and lugged to the respective MCBs and Bus bar as per approved shop drawing.
  • Bunching shall be done as per phase separation respectively R, Y and B.

(e) Moving Parts and Interlock Checks for Switchgear

  • Confirm the correct operation and sequencing of electrical and mechanical interlock systems. Attempt closure on locked-open devices and attempt to open locked-closed devices.

(f) Lubrication of Switchgear and Switchboards

  • Check for appropriate lubrication on moving current-carrying parts and moving/sliding surfaces to keep everything operating smoothly. This includes hinges, locks, and latches.

(g) Insulators and Barrier Checks for Switchgear

  • Tracking is an electrical discharge phenomenon caused by electrical stress on insulation. This stress can occur phase-to-phase or phase-to-ground. Although tracking can occur internally in certain insulating materials, these materials as a rule are not used in medium- or high-voltage switchgear insulation. Tracking, when it occurs in switchgear assemblies, normally is found on insulation surfaces.
  • Electrical insulators should be inspected for evidence of physical damage or contaminated surfaces. Damage caused by electrical distress is normally evident on the surface of insulating members in the form of corona erosion or markings or tracking paths.
  • Inspect barrier and shutter assemblies for proper installation and operation. All active components should be exercised, mechanical indicating devices should be inspected for correct operation.

(h) Moisture and Corona Inspections for Switchgear and Switchboards

  • If corona occurs in switchgear assemblies, it is usually localized in thin air gaps that exist between a high-voltage bus bar and its adjacent insulation or between two adjacent insulating members. Corona might also form around bolt heads or other sharp projections that are not properly insulated or shielded. Corona in low-voltage switchgear is practically nonexistent.
  • Inspect for evidence of moisture or corona when performing maintenance inspections. On outdoor assemblies, roof or wall seams should be checked for evidence of leakage, and any leaking seams should be sealed with weatherproof caulk.
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