RCD / LED problem

[Octopus]

Next time don't give the customer the option.

They are running as business ... Hours lost cost far more than a couple of rcbo's

Best get back on site and use your tester

 

[Dillb]

Costing you now though isn’t it.

 

[Emkey]

You are absolutely right about not giving a customer an option in this case.

I will be there next week and try to get an earth leakage metre too. They are not cheap but seem very useful.

 

[Emkey]

It's costing me a lot cause the place is 100 miles away. Only agreed to do it because the owner is a friend of a friend. Big mistake.

 

[PEG]

The clamp is a must,on issues such as this,but if the only thing i had was a screwdriver,i would be pulling the neutral on that mcb switched lighting circuit,and seeing what happened...

 

[Toneyz]

Can we rule out that these LED lights are nothing to do with the s
unbeds? Edit these are just doing lighting in the shop.

So the LED lights are only in the shop ceiling are they?

 

[Emkey]

That's right. LEDs are on the walls and don't suppose to have anything to do with the Beds.

 

[buzzlightyear]

the plot thickens

Hang on is the RCD required by
1) insurance
2) council
3) customer
4) installer

the only persons who is missing from the that is the candle stick maker ,now cluedo comes to mind

 

[Midwest]

Seems a less than helpful night on the forum.

 

[Octopus]

Seems a less than helpful night on the forum.

posted at 10.56 pm on a Saturday night!

Could have been a lot worse.................

 

[Richard Burns]

Theoretically the LEDs cannot be affecting the RCD on a different supply as the RCD is only monitoring the outgoing circuits.
Possibly, but I am not sure how, the LED dimmer is introducing a DC component that is masking the RCD operation; alternatively if there is a Neutral Earth fault on the sunbed side of such resistance that is just tripping the RCD and there is also a neutral earth fault on the LEDs once switched on then this would give parallel paths for the neutral current and so reduce the current seen by the RCD below its tripping threshold.
If the sunbeds are switched on by a double pole switch then it is possible that there is a difference in arcing across the poles so that the RCD occasionally thinks there is an imbalance and the LEDs just happen to coincide with the trip times. This could be tested by connecting the "working" sunbed to one of the other sockets.

 

[johnduffell]

So when the LEDs are on, the RCD doesn't trip? All one one RCD?
If so it could simply be the sun beds are leaking inductively to earth and the LEDs are leaking capacitively. So they cancel out enough to stop a trip. Not sure how well RCD trip if you leak imaginary power, but either way the above suggestions about one 3p RCD per bed make sense.

 

[Deleted member 26818]

So when the LEDs are on, the RCD doesn't trip? All one one RCD?
If so it could simply be the sun beds are leaking inductively to earth and the LEDs are leaking capacitively. So they cancel out enough to stop a trip. Not sure how well RCD trip if you leak imaginary power, but either way the above suggestions about one 3p RCD per bed make sense.

Did you test the RCD?
Did you test the RCD with the LEDs on or off?

 

[johnduffell]

Did you test the RCD?
Did you test the RCD with the LEDs on or off?

I guess that was aimed at the op, not to me

 

[Deleted member 26818]

I guess that was aimed at the op, not to me

Sorry, thought you were the OP.
You need a picture.

 

[johnduffell]

You need a picture.

Good point, never intended to hang around here long enough to need one, but turns out you lot are more welcoming then i expected

 

[Wilko]

Hi - The shop's LED lights with no functional switch caught my eye - an indicator perhaps the rest of the place isn't wired as we might expect?

 

[Octopus]

Hi - The shop's LED lights with no functional switch caught my eye - an indicator perhaps the rest of the place isn't wired as we might expect?

I was wondering this but he has stated the new rcd board is wired independently of the existing cu which supplies the led light circuit ......

Very odd

Hope we get feedback once he’s been back on site ..

 

[marconi]

http://www.solansunbeds.co.uk/How_to_Set_up_a_Successful_Tanning_Salonv1.2.pdf

See page 16 of 17 of the reference which is quite clear that if RCD protection is provided for Solan sunbeds then the trip current difference must be 100mA and not 30mA to take into account the accumulated leakage from the many ballasts and hot humid ambient air inside the equipment. What do the technical installation instructions say for the make and model of tanning machine for which you have provided electrical supplies?

 

[Wilko]

Gives a good insight as to why RCBO should be used for each one. Hopefully 30mA rating will be ok, as I'm not overjoyed at the idea of stepping in and out of a metal box with 100mA ... (is it just me?) Still no clue as to the LED role in all this .