Electrical Installation Method Statement for MDB and MCC

Below is a precise electrical installation method statement that covers installation of main distribution board and MCC panel board in compliance with the approved design, drawings, manufacturer instructions and material submittals.

The electrical or MEP project manager is overall responsible for the implementation of this procedure and any relevant documents/standards.

Site Engineer will be responsible for all construction activities at the site and will directly supervise skilled workmen at the work site.

Quality and site engineer will  be responsible for arranging and controlling the inspection and testing activities.

Furthermore, it is the responsibility of each individual employee in the project to take due care to ensure their own personal safety and that of their work colleagues.

Below are the steps that involve the complete activity of MDB and MCC installation.

• Delivery and Inspection of MDB and MCC panel board upon delivery at site
• Preparation for the installation work
• Setting out of works
• Installation of MDB and MCC panel board
• Inspection of MDB and MCC panel board

Below is list of necessary materials, tools and equipment.

• PPE for all staff and labor
• Measuring tape and setting out markers
• Electric Drill hammer
• Fitters tool box
• Electricians tool box
• Certified scaffolds / Step ladder
• Multitester / Megger Tester

Material Delivery Handling & Storage

The MDB and MCC panel board material should be according to the site requirement and in accordance with the approved/design drawings.

It should be noted that the materials used in this work are of valuable nature and that they shall be stored in a secure location, and access to these materials  shall be strictly controlled.

All materials delivered to the site will be first inspected by the store In-charge / site in-charge.

Delivered materials shall be checked in accordance with the site requirement, approved design and material qualification.

Materials must be free from any damage caused during the delivery to site.

Delivery documentation shall be checked for completeness.

Any defective or damaged materials shall either be returned to the supplier’s facility or stored on site at a suitable quarantine location.

Materials will be stored in a clean / dry place and adequate covering by tarpaulin sheets to be provided to protect the equipment from deposition of construction dust till they are finally shifted to their installation location.

On arrival at construction site materials shall be inspected to ensure that these are as per approved material  submittals in terms of make, model  type, country of origin and capacity.

Material inspection request shall be submitted for consultant  approval & acceptance before proceeding with installation of MDB and MCC Panel.

Preparatory Requirements for MDB & MCC Panel Installation

Check that the shop drawing and design drawings for MDB and MCC panel board installation are approved and available at the site.

Ensure the availability of site clearance and access in the work area of distribution board installation.

Make sure that the work area is clean and safe, all necessary temporary services are available.

Prior to installation of MDB & MCC Panel board, the supervisor and foreman will verify and ensure that all health and safety requirements have been complied with and necessary control measure are in place.

Supervisor and foreman will orient and familiarize all the technicians and labors regarding relevant approved shop drawings, technical submittals, manufacturer installation procedures / details, acceptance criteria and safety requirements.

The supervisor and foreman will examine surfaces to receive the MDB & MCC Panel for compliance with installation tolerance and other clearance required as described in the installation requirement.

Installation will not proceed until satisfactory conditions have been achieved.

Sequence of Electrical Installation of MDB/MCC

Ensure approved documents like shop drawings, SLD, electrical room layout and load schedules are available and confirm that panels are as per schedule.

Shift the panel on its designation location, packing/covering should remain on the panel until it is finally installed or mounted.

Check the label / marking to ensure the right board is selected before installation.

Mark the fixing position of the panel as per shop drawing.

Make holes and fix the anchors as per the given installation details and approved drawings/details.

Fix the panel with proper metal plugs and bolts.

Ensure the installation is straight/plumb and leveled.

Suitable knock-out at the top and bottom of the panel shall be used for incoming and outgoing cable entry.

File the knockout to suit the cable glands and lugs for rigid termination.

Ensure the bus bars and interconnecting terminals are free from dust and damage.

After fixing panel into its final location, the following must be done:

All components of the panel such as ACB, MCCB, MCB, Relays, Fuses, Meters, CT’s, Contactors, Terminals etc., Shall be verified against the approved panel drawing and SLD for correct rating and size.

Check the breakers by referring to the approved load schedule.

Perform insulation resistance test of the panel by using Megger tester.

Conduct insulation resistance test of the cables before termination.

Terminate all the circuits to its respective breakers with proper  ferrule identification.

Dress the cables neatly with cable ties / cables cleat.

Double check the connections by tightening the terminations.

Clean the panel from inside and outside by means of vacuum to remove the dust and solid particles inside the panel.

Provide identification labels as per specifications, approved submittals and schedules.

Place and attach the approved load schedule copy inside the panel door.

Keep the approved single line diagram near the MDB/MCC (Photo framed), wall mounted inside the switchgear room.

Inspection and Testing

In progress works shall be monitored for quality of workmanship and installation against approved construction drawings by the relevant electrical supervisor.

Upon completion of installation of MDB / MCC, comprehensive inspection shall be done by QA/QC engineer.

After internal inspection the installation works shall be presented to consultant for final approval.

Housekeeping shall be of good standard and all cut pipes, cables and debris shall be removed.

Inspection Checklist for MDB & MCC Installation

Check the distance between panels and panel to walls have met the minimum required distance.

Check general arrangements of the components, internal wiring and cleanliness.

Check the panel against approved shop drawing to ensure correct components ratings are installed.

Check if bolts and nuts are properly tightened.

Check the earth bonding of the components.

Check the meters and selector switches are in good condition.

Check if all cubicles is properly labeled and identified.

Check if safety covers are in place and all covers are secured properly.

Check interconnections between cubicles and busbar connections.

Check the installations of grommets at knockouts and terminations after dressing of cables.

Check for providing rubber mats to the entire length of MDB / MCC panels.

Check ID tags/name plate, cable labels and warning signs have been affixed.