The twin problems of housing numerous single phase circuits with some requiring earth leakage protection to 30mA on one board has been solved for a West Country garden centre using a Hager split load Invicta 63 TP&N board.
With a three phase supply coming into the board, contractor Bob Tyler split each outgoing way into three single phase ways since Hagerís SP&N MCBs and RCBOs can also be used on the three phase boards Ė via an easy to fit link. This multiplied the number of outgoing ways available.
In addition earth leakage protection to 30mA is needed for areas open to the public, while 100mA protection is used for other areas that are not accessible.
Using a split load TP&N board, Tyler used a 100A main switch with the outgoing ways individually protected by 30mA RCBOs for additional earth leakage protection. The small cost premium is balanced out by the fact that in the event of any earth leakage only one circuit will trip so public areas are not completely isolated. It also makes fault finding easier in an emergency call out.
For areas where there is no public access, such as the general offices, a 100mA RCD provides earth leakage protection while single phase MCBs provide overload circuit protection.
All the circuits in public areas are switched from behind reception using a 24 way grid panel, via contactors located in an extension box above the main distribution board. Both the board and the extension box are also located behind reception for ease of installation and simple fault finding. In such a public area the aesthetics of Hagerís board and the extension box with reinforced smoke glass doors was another reason for its specification.
The garden centre itself has several sections. A Hager panelboard with a 400A incomer supplies the reception area board and other areas in the centre. Phase two, due to be completed before Christmas, will use a similar solution in a separate area of the centre.
For further information please contact:
Telford TF1 7FT
Tel: 01952 677899 or e-mail us at email@example.com
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