A 100a Distribution Board will be used to power Block L. A ring circuit will provide power to the substation room and Generator/switch room (labelled Sockets, Generator/Switchroom). It will be protected by a 32A BS EN 60898 type C RCBO. The RCBO type C is used as equipment could either be plugged in from outside or attached to an inductive load. Another ring circuit will provide power for the workshop and restroom (labelled Sockets, Workshop/Restroom), this will also be protected by a 32A BS EN 60898 type c RCBO as again, equipment could be plugged in from outside or attached to an inductive load, as well as equipment being used within the restroom. The Electric Roller Shutter Door (labelled Motor Door) will be wired on its own radial circuit as if it faults due to wear it will not trip out a ring circuit. It will be protected by a 16A type D MCB to allow for the motor.
The Block L outside lighting will be on a radial circuit protected by a 10A type c BS EN 60898 RCBO, this will be used to allow for the inductive discharge lighting and the 10A capacity for future lighting to be added. Calculations:
150W x 5 = 750W 750W x 1.8 = 1350W (1.8 discharge lighting factor) I = P
= 1350W = 5.87A load current
The inside lighting fittings will be twin 6ft fluorescent luminaires protected by either a 6A or 10A type B MCB circuit depending, with each tube rated at 70W. They will be divided into five circuits. current per fitting = P x 1.8 (discharge lighting factor)
current per fitting = (2 x 70W) x 1.8
current per fitting = 1.1A
number of fittings = __MCB rating___
current per fitting
number of fittings = _6A_ = 5.45
number of fittings = 10A = 9.09
The 6A MCB will have 5 fittings...
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