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Shallow Electrical Box

Posted by John Molnar, on
My daughter is disable and has problems using the bathroom when it is cold. I replaced an existing fan with this model which has a heater Delta BreezRadiance RAD80LED. The light and fan are wired together using the existing switch. I ran a new line to a dedicated 15 amp beaker for the heater which I intend to control with a no hold 15 amp timer switch intermatic EI205 . Problem is I cut hole for new box idirectly across from existing box on opposite wall. I found a shallow box with an extension to hold the wires but still had to cut back off for it to fit. The back of the new box would be formed by the back of the box on the opposite wall. Can I safely proceed as I planned?
Stephen Johnson

Stephen Johnson

Hi John, in short no.. Putting in a new circuit to a bathroom comes with a number of legal requirements. Firstly the fault protection needs to be sufficient, either the distribution board needs to have appropriate RCD protection or the dedicated breaker needs to be an RCBO or similar if the board doesn't have an RCD fitted, just a dedicated breaker on its own is not sufficient fault protection to satisfy legal requirements as its cut off fault power is 10's of thousands of times higher than the 0.003 amps set as the legal requirement. Unless the control timer is specifically designed to be within the bathroom it should be outside of the bathroom, it is never in any circumstances appropriate to have two electrical boxes back to back. Wiring regulations specifically prohibit it because of the very real risk of short circuits between circuits especially when a special location such as a bathroom is involved. I hope that helps, Kind regards Steve Johnson Creation Living Space Ltd

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