Noisy RCD. - BG brand

[1Justin]

I thought I'd try a BG CU.

The RCD's are noisy under load. Perhaps 2KW sets them off, a buzz which is quite audible from a few feet away. I swapped the noisy RCD for the second (since that side was still unused when I worked this out), the other one is also noisy, but less so.

Both switch fine, measure up (disconnect) fine, Zs fine, and no signs of anything wrong, no smell, heat etc. - Just the noise.

Is this normal for a BG brand RCD? Does anyone have anything to offer, or should I take them back?

 

[somersetsparks]

have yer tried giving then a tap?

 

[diditrain]

Fitted a few and never heard any buzzing before. Not normal.

 

[Deleted member 72666]

have yer tried giving then a tap?

With a hammer....

 

[telectrix]

could be a fault on the circuit. i fit BG regularly and ain't never herd them buzz, but then again, i'm a bitt mutton, so who knows? at least they not got recalls.

 

[MDJ]

Is this normal for a BG brand RCD? Does anyone have anything to offer, or should I take them back?

No it's not and yes take them back, unless you have not gripped them on the busbar and they are loose, seen it done tbh.

 

[chopper76]

Inductive or dimmed loads?

 

[GLENNSPARK]

check all connections on new dis-boards justin....that includes factory ones ....

 

[1Justin]

All connections are tight. I checked that already, but I will re-check since all the screws on thes BG (on the MCB's and the N E bar) are very stiff.
The load(s) which cause it may well be a bit inductive, because it's the heavy (heating) loads - eg kettle.
No dimmers.
Circuit all measures OK

The buzz under load is low level, but noticeable in quiet space.

It sounds like slight 50Hz rattle - like you might get from a loose winding of a transformer.

Just had an idea, I could pop the RCD into my own CU to try it, maybe worth a go.

 

[GLENNSPARK]

All connections are tight. I checked that already, but I will re-check since all the screws on thes BG (on the MCB's and the N E bar) are very stiff.
The load(s) which cause it may well be a bit inductive, because it's the heavy (heating) loads - eg kettle.
No dimmers.
Circuit all measures OK

The buzz under load is low level, but noticeable in quiet space.

It sounds like slight 50Hz rattle - like you might get from a loose winding of a transformer.

Just had an idea, I could pop the RCD into my own CU to try it, maybe worth a go.

are you sure about this statement justin?

 

[GLENNSPARK]

check how much leakage by clamping all the tails together

 

[1Justin]

Hi Glenn,

Well I don't know, but a kettle is heated with a ceramic wire coil. Not exactly a motor winding I know, but it's not going to be a pure resistor. Anyhow, clutching at straws here since Chopper posed the question.

"Clamping all the tails together?" I'm not with you on that one.

 

[GLENNSPARK]

Hi Glenn,

Well I don't know, but a kettle is heated with a ceramic wire coil. Not exactly a motor winding I know, but it's not going to be a pure resistor. Anyhow, clutching at straws here since Chopper posed the question.

"Clamping all the tails together?" I'm not with you on that one.

clamp both the tails with a leakage clamp....any mA shown will be the leakage...i suspect those RCDs are near their limit....

 

[Marvo]

It may be it's close to the tripping threshold or it may be there's something wrong with them. To be honest if there's no problems with the circuits I'd return them to the wholesaler for a warranty and get them to investigate the issue, bottom line is they shouldn't make a noise and the customer will probably complain sooner or later.

 

[1Justin]

Hi Glenn, Hmm leakage. Firstly might a standing leak show up as significant offset in the break time between positive and negative cycles? (I see no big difference).

& Insulation resistance is very high.

I also don't have a current clamp - maybe I should have one, would be handy from time to time. Thanks.

 

[GLENNSPARK]

It may be it's close to the tripping threshold or it may be there's something wrong with them. To be honest if there's no problems with the circuits I'd return them to the wholesaler for a warranty and get them to investigate the issue, bottom line is they shouldn't make a noise and the customer will probably complain sooner or later.

well this was my initial thoughts here marv...

i will say this though Justin....a while back one of the counter staff at a screwfix up here in Leeds mentioned they`d had a lot of these british general boards back with issues about this n that....

 

[GLENNSPARK]

Hi Glenn, Hmm leakage. Firstly might a standing leak show up as significant offset in the break time between positive and negative cycles? (I see no big difference).

& Insulation resistance is very high.

I also don't have a current clamp - maybe I should have one, would be handy from time to time. Thanks.

a requirement really when RCDs are about...the alternative is to ramp it off load...then again on load...the difference will be leakage....

 

[1Justin]

Yep, I've just been looking up clamp meters on line, need one with good resolution down to mA and AC DC also.

I was unsure of the BG board in general, maybe not again..

Mechanically it's nice, better than MK. The front goes on really well and doesn't bend. (- Perhaps removing it is a tad too easy though with two quarter turn locks). The switches run right to left, but the earth bar is numbered left to right. - RCD is right to left so to speak, which means I couldn't try it out this evening in my own MK board since the busbar on wrong side.

 

[Marvo]

Yep, I've just been looking up clamp meters on line, need one with good resolution down to mA and AC DC also.

I don't know how you're going to test the actual leakage without one. I would look at the Dilog earth leakage clamp, it's very reasonably priced and gets good reports but I'm not sure about it's DC capabilities.

 

[GLENNSPARK]

here you go Justin...£39 off fleabay...
now, i`v got one of these....and their OK...

Mini AC Leakage Current Tester ST-9810 (AMECaL) | eBay