- Reaction score
- 1,556
Had a phone call the other day regarding a dimmer switch and 5 x 50watt dichroic lamps.
Caller said that when switching off the lights which are on a dimmer switch the was a flash from one and all the lights went out plus MCB tripped.
They reset the MCB but the lights in that room would not come back on, when I went round I checked out light fittings found them all to be ok including the one that the flash had come from but the lamp had blown.
I have known when incandescant lamps blow they can take out the MCB but never heard it take out a switch.
Only reason I can think it took out the switch, is that the dimmer switch was rated 400w max(approx 1.6A) and with the MCB being a B type it needed 18-30A to trip thus 10-20 times current rating of switch flowing through it for an instant.
Caller said that when switching off the lights which are on a dimmer switch the was a flash from one and all the lights went out plus MCB tripped.
They reset the MCB but the lights in that room would not come back on, when I went round I checked out light fittings found them all to be ok including the one that the flash had come from but the lamp had blown.
I have known when incandescant lamps blow they can take out the MCB but never heard it take out a switch.
Only reason I can think it took out the switch, is that the dimmer switch was rated 400w max(approx 1.6A) and with the MCB being a B type it needed 18-30A to trip thus 10-20 times current rating of switch flowing through it for an instant.
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