Method Statement for Installation & Testing of Electrical Distribution Board

This method statement will help the electrical engineers and supervisors for the installation of distribution board for an electrical project.

Additionally site team will need detailed information of all aspects associated with the installation process in order to complete the job inline with the contract or project requirements, specifications and approved electrical drawings.

Before the start of installation work, all material received at site shall be inspected by consultant engineer and ensure that the material are as per approved material submittal.

Any discrepancies, damages etc. shall be notified and reported for further action. Materials found not suitable for the project are removed from site immediately.

High caliber and well trained charge hands and electrician will be dedicated to carry out the installation works for distribution board under the supervision of the project team shown on the project organization chart in accordance with the approved shop drawings.

The following indicative tools shall be available on site as a minimum for the installation of the distribution board DB.

• Continuity tester
• Multimeter tester
• Loop impedance tester
• Polarity tester
• RCD Tester
• Technician hand tools

Health & Safety Requirements

• All Safety Regulations and requirements as per the project approved EHSP plan must be implemented and monitored on site at all times by electrical staff.
• Safety induction and training to all involved site staff will be provided by the main contractor prior to commencing any activities on site.
• Tool box talk will be provided by safety team to highlight and hazards or safety regulations to be followed during the installation of the Distribution Board on site and attendance singing sheet will be kept.
• All Personal on site must wear (PPE) equipment at all times
• Ensure proper barricading to the work area with Standard safety warning signs to be placed all around, visible to the public at any point where work on site to be performed
• Traffic Management with proper access to and from the site during the installation process shall be maintained until completion of the works
• The approved Risk Assessment Sheet must be implemented during the work course on site to prevent or minimize any identified risks during the execution of the job on site

Installation Sequence of Distribution Board

Upon receiving the Distribution Boards, material inspection is conducted.

Size of the Distribution Board shall be as per approved schedule and standards.

Examine the location to receive Distribution Board, for compliance with requirements for installation tolerances and clearances and after installation for periodic service as specified in the construction drawings.

Prior to moving the Distribution Board to the appropriate location, check the dimensions of plastering Level and the finished floor level to comply with the requirements of current revision of specification.

Install the empty Panel Box at its position and fix it with nuts and bolts at their place properly.

Install switchgear panel with its accessories inside the box as per the manufacturer’s written instructions.

Tighten electrical connectors and terminals according to manufacturer’s torque tightening specifications values.

Sample or mock up inspection shall be conducted in case of first DB installation.

The enclosure shall be protected from plastering.

After completion of all electrical installation, remove dirt, and construction debris, Clean the work location and site is left in a tidy fashion.

Raise Inspection Request to consultant Engineer, before the testing of DB’s distribution boards.

Pre-commissioning of SMDB’s:

Check units, wires & cable termination and tightness as per drawing.

• Check the Earthing termination of panels
• Check the provision for BMS interfaces
• Check the load schedule drawings in panels
• Check meter connection
• Check rating and name plates as per approved drawing.
• Check feeder identification labels and panel mounting devices are provided with labels.
• Check bus bar joints connection tightness, where applicable or filed assembled.
• Check incoming & outgoing cables termination and tightness on both sides.
• Check torque of the bolts & mark it with permanent red marker
• Ensure the panel is clean and free from foreign matter.

Pre-commissioning of MCC’s & Control panels:

• Completion of electrical installation including termination of all cabling and fully documented panel as per commissioning sheet
• Check the provision for BMS interfaces
• Check the load schedule drawing in panels
• Check the rating and name plates as per approved drawing
• Check feeder identification labels and panels mounting devices are provided with labels
• Check incoming & outgoing cables termination and tightness on both sides.
• Check bus bar joints connection tightness, where applicable or field assembled
• Check the torque of the bolts & mark it with permanent red marker
• Ensure the panel is clean and free from foreign matter

Pre-commissioning of FDB’s:

• Check name plates as per drawing and relevant specification.
• Check MCB’s/RCD’s/Isolator are as per approved load schedule and drawing
• Check the wiring and cable termination tightness
• Check grounding of DB
• Ensure DB load schedule is available inside the DB

Visual Inspection of Distribution Board

• All insulator and insulation material are physically inspected and are clean and free from damage
• Ensure that circuit breakers and compartments are as per drawing and satisfactory
• Installed switchgear matches single line drawings, schematic and equipment schedule

Cold Test Procedure

• Check the insulation resistance of cables, if not done prior to termination.
• Check the continuity test of cables, if not done prior to termination
• Bolt torque is check within assembly and QC marks are available
• Check the termination tightness of cables and wires.

Live Test of Distribution Board

• Check the operation of MCCB’s and door interlock
• Check the operation of MCC/ Control panel and door interlock
• Check earth fault loop impedance test
• Verify MCCBs operation by tripping manually
• Verify the indication lamps are working properly ( MCC)
• Verify speed control by overriding to maximum and minimum speeds ( MCC)
• Record voltage and Amps, cross check the reading with panel meters.

Quality Control Arrangements (Testing, Inspections & Records)

• All Quality control measures and site inspections will be carried out in accordance with the approved quality plan
• Quality Assurance and Quality control of all aspects of the installation process must be monitored at all times by Project Engineer and Site Engineer
• Following the installation of the Distribution Board, electrical engineer will conduct initial inspection prior to submit a formal request for inspection (IR) by the client.
• Request for inspection shall be prepared by site engineer and shall be issued to consultant for further inspection with Consultant.
• Site engineer shall co-ordinate with Client / Consultant to arrange for site inspection and submit an (IR) 24 hours minimum before inspection date.