King Arthur
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- Jun 22, 2019
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Looking at this for a friend (honestly!). Bathroom has six LED ceiling downlights on two circuits of two lamps (over the bath) plus four lamps. Both circuits controlled by separate dimmers. The 4-light circuit also has an extractor fan wired to it. Basically, the 4-lamps + fan are not working, the two lamps are working and dimming ok. Immediate suspicion was that the dimmer for the 4-lamps+fan had failed.
I removed the faceplate comtining the two dimmers and swapped the wires to them. As suspected, the 4-lamps+fan now work and the two lamps over the bath do not. So it looks like a failed dimmer, which should be an easy fix. So far, so good.
My question concerns the extractor fan. It's a basic two-wire fan and does not overrun (how could it with only two wires?). I've not checked but my guess is that it has simply been wired into the 4-lamp circuit. It's an old-ish installation with red/black wiring to the fan and was originally switched (the dimmer was only connected about one year ago), which was probably ok at the time. The light switches were, apparently, replaced with dimmers by a pro electrician about a year ago in full knowledge of the fan.
After replacing simple light switches with dimmers the fan speed varies as the LEDs are dimmed. Clearly this is not ideal and I'm wondering if this could have led to the failure of the dimmer after only one year?
I see three options here:
1. Replace the failed dimmer module. Perhaps it was 'just one of those things' although I'm sure we'd all expect it to last more than one year.
2. Replace the failed dimmer module with a switch. The existing dimmer module is fitted to the faceplate with a nut and is easily removed. The issue would be finding a suitable switch with a knob that matches the existing one - ie it would look like two dimmers on the faceplate but only one would actually dim. But that's just a cosmetic issue really.
3. Replace the failed dimmer AND replace the fan with a more modern fan with overrun facility. My understanding is that such units have a permanent live connection and a 'trigger' connection, which would be compatible with the dimmed lighting circuit - ie lights are switched on with any brightness which triggers the fan to switch on at full speed until lights are switched off. The problem with this option is getting a live connection to a new fan set into a fully-tiled bathroom.
If it was me, I would replace the dimmer with a simple switch and leave the fan alone but my friend insists she wants all the lights to be dimmable.
What does the panel think?
I removed the faceplate comtining the two dimmers and swapped the wires to them. As suspected, the 4-lamps+fan now work and the two lamps over the bath do not. So it looks like a failed dimmer, which should be an easy fix. So far, so good.
My question concerns the extractor fan. It's a basic two-wire fan and does not overrun (how could it with only two wires?). I've not checked but my guess is that it has simply been wired into the 4-lamp circuit. It's an old-ish installation with red/black wiring to the fan and was originally switched (the dimmer was only connected about one year ago), which was probably ok at the time. The light switches were, apparently, replaced with dimmers by a pro electrician about a year ago in full knowledge of the fan.
After replacing simple light switches with dimmers the fan speed varies as the LEDs are dimmed. Clearly this is not ideal and I'm wondering if this could have led to the failure of the dimmer after only one year?
I see three options here:
1. Replace the failed dimmer module. Perhaps it was 'just one of those things' although I'm sure we'd all expect it to last more than one year.
2. Replace the failed dimmer module with a switch. The existing dimmer module is fitted to the faceplate with a nut and is easily removed. The issue would be finding a suitable switch with a knob that matches the existing one - ie it would look like two dimmers on the faceplate but only one would actually dim. But that's just a cosmetic issue really.
3. Replace the failed dimmer AND replace the fan with a more modern fan with overrun facility. My understanding is that such units have a permanent live connection and a 'trigger' connection, which would be compatible with the dimmed lighting circuit - ie lights are switched on with any brightness which triggers the fan to switch on at full speed until lights are switched off. The problem with this option is getting a live connection to a new fan set into a fully-tiled bathroom.
If it was me, I would replace the dimmer with a simple switch and leave the fan alone but my friend insists she wants all the lights to be dimmable.
What does the panel think?
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