Why do some double socket spark when you switch them on/off
- Thread starter u587162
- Start date
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Unless there is some load attached, they will not spark. Sparking/arcing at a switch under load, is absolutely normal, but the amount will vary dependant on the load and the instant in the mains cycle, when the switch is thrown.
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The arc is created when the contacts break ( open OFF), If there is an arc when the contacts close it will be due to the contacts bouncing open before closing properly.
The duration of the arc depends on the speed at which the contacts separate. When the contacts open slowly the arc can re-start on the next half cycle of the mains voltage. ( 10 milliseconds later ) This can continue until the gap is too wide for the mains peak voltage ( worse case 265 volts ( 240 x √ 2 ) ) to re-strike the arc. Typically re-striking will not happen when the gap is wider than 1 mm but depends on atmospheric conditions.
From an MK specification
PHYSICAL
AMBIENT OPERATING TEMPERATURE –5°C to +40°C
IP RATING IP2XD
MAX. INSTALLATION ALTITUDE 2000 metres
A gap of 3 mm is ( almost ) certain to prevent re--striking.
Some switches are made from opaque plastic and the arc cannot be seen, others use semi translucent plastic through which the arc can be seen,
..and just seeing the arc can worry some people that there is an issue with a switch, whereas it is quite normal.
A short duration arc ( one half cycle ) will happen but some switches and sockets do have arc durations longer than that suggesting the gap has not reached 1 mm separation before the next voltage peak.
EDIT the next voltage peak of the 50 Hz AC waveform which is 10 milliSeconds later
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It is very normal, they all do it to some degree or other and some are more visible than others. I'm using the Wickes cheapies to replace the MK sockets in my kitchen as they fail. More details available if desired.
You are using cheapies to replace well known MK branded ones?
Or do you mean replacing cheapies with MK ones?
I AM REPLACING THE FAILING MK STUFF WITH CHEAPIES and so far I've found them to be more reliable. We refitted the kitchen about 15 years ago and I decided to use decent stuff, MK DSSO's with neon, purchased 10 for the price break for the 7 required. all 3 spares got used up as replacements and now there is only one left in use.
So far I have not had to replace a Wickes cheapie...
And in my day work I have always found I'm replacing MK sockets far more frequently than all the other makes put together and no one will ever be able to convince me it's purely down to MK having that much of a market hold.
I work for an industrial company. Several of our contractors have moved to Schneider hardware recently. They must get a good price in bulk because in the merchants I've used its rather expensive. Maybe they are focused on the bulk market.
MK quality is just not what it used to be. It used to be the best, most reliable and most robust designs, but not now. Crabtree was another good make, but not quite as good.
What can I do to make sure that future ones I buy dont spark like that? What brands to consider?
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