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LED won't go out on replacement 45a DP switch

Postby eirwen » Sun Oct 04, 2009 2:00 pm

Hi there, I'm new to this forum and I'm really hoping someone can offer me some help.

I've just replaced the 45a dp rocker switch which provides the supply to my electric heating boiler. I think I've done something wrong because the indicator LED remains on all the time, even when the switch is in the "off" position. The switch works (i.e. when it's "on" the boiler receives supply and when it's "off" the boiler receives no supply) but it concerns me that the LED won't go out.

The old switch had started to smell really bad and on investigation I discovered it had melted around the netural wire which had gone totally black. I expect this is because the switch is taking such a large load and is in the "on" position most of the time (is this correct?).

I stripped back the burned cable really carefully before rewiring the new switch but could this be the problem?

Any advice would be greatly appreciated.
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Postby kbrownie » Mon Oct 05, 2009 11:43 am

Sounds like you've had a short at some stage, this could be down to loose connection in the plate and two live conductorsLine and Neutral have touched.
But if the smell continues get an electrician in straigt away as other factors could be incorrect fuse rating for cable causing insulation failure do to cable over heating. I would recommend this circuit was not used until it has been inspected.

When you buy new accessories they usually come with diagrams of the correct way to wire them up, check that out too.
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Postby eirwen » Tue Oct 06, 2009 6:05 pm

Thanks so much but it's fixed.

I took the new switch face off again to double-check and I'd got the wiring wrong. I had copied the wiring on the previous switch as a guide (marked "IN" and "OUT") but the new one was by a different manufacturer and it had "FEED" and "LOAD". I assumed the position of the terminals would be the same (mains supply at the top and heater cable at the bottom) but the different manufacturer had reversed them so I just swapped them over and now it's working.

I appreciate your response and will no doubt be back here for advice in the future.
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Postby DEEARR2 » Tue Oct 06, 2009 6:25 pm

Sound as though you may have the feed and neutral from the mains and the feed and neutral to the load in the wrong connections. Worth a check.
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