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Overview
Many major construction projects now require Mains Distribution Assemblies (MDAs) to incorporate Form 4b Type 7 segregation, which enables outgoing circuits to be safely connected or
disconnected without the need to isolate the overall MDA. Adopting Form 4b Type 7 segregation eliminates disruption to the site, or the need for out of hours work, in order to carry out routine
activities without compromising safety.
For a recent project we supplied 2 no. MDAs each rated at 3200A. These large panels, rated at IP55, also incorporated a host of other features including surge protection, hinged inset plates, door stays, test sockets and a 1600A plug-in facility, enabling a 1000kVA stand-by generator to be safely and easily connected. The stand-by incomer was key interlocked with the 3200A mains incomer, ensuring the board could only be supplied from either the mains or the stand-by supply.
On the distribution side of the assembly, outgoing circuits were 4P rated up to 800A, with each protected by a variable time and current modular RCD, providing Type A protection. Each RCD incorporated associated test sockets allowing periodic testing to take place without the need to remove inset plates. On circuits up to 630A, inset plates were hinged, preventing doors from being closed until inset plates were lowered in to position.
These bespoke panels were developed from our standard range of Form 4b Type 7 MDAs, which are stocked in ratings up to 1600A.
If you have a requirement for a non-standard or high current Form 4 MDA, please contact our Projects Team, who will be pleased to assist.
Project No:
SP120
Industry
Construction
Category
Form 4 Standard MDAs, Temporary Distribution
Year
2025
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