Help - split load CU RCD tripping

[Guest rafal]

Just installed my DSC 832 and I have very strange electric problem.

The panel is connected to its own 6A mcb in the non RCD section

of the split load /one section with an isolator switch, other with an RCD/

consumer unit. As soon the mcb is switched on the RCD section trips out!!!!

So far I have found the following:

- works ok with the RCD section off

- it trips with the 832 transformer connected /panel disconnected/

- it trips with the earth wire disconnected

- tried different wire from the CU to the transformer

[Guest]

If you look in the consumer unit you'll see there are 2 neutral bars. You've connected the neutral of the alarm supply to the wrong bar.

[Guest rafal]

If you look in the consumer unit you'll see there are 2 neutral bars. You've connected the neutral of the alarm supply to the wrong bar.

35222[/snapback]

Whoohaaa, result! It is bloody working!

Thank you, thank you, and thank you!!!!

You have just saved my sanity. I feel a bit like a plonker.

But if you do not know, you do not know.

After all I am an electronics engineer not an electrician.

But have no fear, I

[Guest]

No probs, I've seen people do this many times over the years!

I once worked with a firm that had this subby on a job who changed a consumer unit and did this. By the time he'd finished he'd condemned half the appliances in the house and even meggered a couple of lightbulbs for earth faults before someone else pointed out the fault in the CU!

[jb-eye]

No probs, I've seen people do this many times over the years

35250[/snapback]

Lurch you can fix mine now (that was easy). I have a TT system with an RCD MCB DB The intermittent tripping is a pain in the but. ive used insulation tester, issolated load the lot i recken som ferkin mouse is lickin the cable when im not there. Its been behavin itself for about a month and went again so shove it out with the RCD stuff the regs i want a constant supply.

Jef

[Guest]

Tricky one, hard to do a lot from here!

I'm a bit pushed for tiime at the mo but I'll try and give a more useful response later.

For a start, are any of the circuits looking dodgy from the results oif the megger?

If everything is on one RCD you could alter the DB so only certain circuits are on a 30mA RCD and the rest, such as lighting and non socket circuits etc.. are on a time delayed 100mA RCD.

[Guest rafal]

No probs, I've seen people do this many times over the years!

I once worked with a firm that had this subby on a job who changed a consumer unit and did this. By the time he'd finished he'd condemned half the appliances in the house and even meggered a couple of lightbulbs for earth faults before someone else pointed out the fault in the CU!

35250[/snapback]

Sometimes it is unbelievable what people can get away with and still call

themselves professional. People running around with a neon tester

insisting that the spur is ok when the neutral is burned out.

A senior Debenhams electrician moved a 3phase socket and rewired

lewden plug trying to much the colours of the flex cable and the solid core

cable in the socket /blue to blue!/ Lucky I check it before connecting 15k worth

of equipment. I made him a little explanation drawing.

He got very upset with me

[amateurandy]

Interesting comments on electricians skills being made here.

We had a faulty dishwasher that the engineers came back to many, many times. In the end we discovered that it had been built using a batch of faulty actuators (not sure what you call them, they're wax-filled and electrically heated to move valves) so different bits of it kept failing and shorting.

After a few visits and at least 5 replaced controllers one guy decided our house wiring was faulty and stuck a "unsafe do not use" label on the socket. He had "tested" it with some small device and said the earth impedance was too high. Quite how this would blow a dishwasher is beyond me; if it's working properly it won't touch the earth.

I hired a big tester myself and everything in the whole house was fine. The particular socket is right next to the consumer unit and earth point so got the best readings.

So we contacted the electicity board who came out, checked it all and said the earth was fine. They pointed out that as we have overhead supply the Neutral is actually earthed as well - at every other pole on the route they said. Their comments about the dishwasher engineer were unrepeatable.

Of course this was an appliance engineer, not an electrician. The real professionals got it right!

[Guest]

After a  few visits and at least 5 replaced controllers one guy decided our house wiring was faulty and stuck a "unsafe do not use" label on the socket. He had "tested" it with some small device and said the earth impedance was too high.

35363[/snapback]

AKA 'clutching at straws'!

[Guest IM_Alarms]

Shall we just call him an Appliance repair man, rather than engineer!