The Blakley Projects team has recently been involved with an overseas project with a requirement for permanently installed outdoor distribution equipment, which will be exposed to intense, overhead solar radiation. The enclosures provide ingress protection to IP56 and switchgear, bus bars and cabling within the assemblies are all rated for an ambient temperature of 50°C. In addition, the enclosures are painted white to reflect the sunlight; sun canopies are also incorporated to protect the main enclosure bodies from the effect of direct sunlight.
The overall package comprised of a series of distribution assemblies. The primary distribution assembly is shown above and is rated at 1600A. It incorporates an incoming automatic changeover arrangement provided by 2 no. 1600A 4P motor operated MCCBs with mechanical and electrical interlock (to prevent simultaneous closure), controlled by a Deep Sea 0334 controller, which also controls the stand-by generator. The two MCCBs supply a common bus bar assembly, which feeds a series of MCCBs fitted in to distribution compartments located at the front and rear of the enclosure. Each outgoing circuit incorporates a
multi-function meter, which includes a kWHr function.
The sub-distribution assemblies are shown on page 2 of the pdf. Initially, all sub-distribution assemblies are to be fed from individual generators, and a separate generator connection chamber is fitted to the rear of each enclosure. Each set of incoming generator terminals is connected to a generator incoming switch within a panel. The generator incomer is key interlocked with the panel’s mains incoming isolator, which prevents the two incomers from being closed at the same time. The permanent mains supply enters the panel via a removable gland plate in the underside of the enclosure.
All of the sub-distribution assemblies have IP56 ingress protection. Some assemblies incorporate 400V socket outlets with individual MCB and RCD protection, to feed portable or plug-in equipment. Other
sub-distribution assemblies incorporate Schneider Powerpact 630A MCCB pan assemblies fitted with distribution MCCBs rated up to 250A. Please see page 2 of the pdf for further details.