New Brew Rig Controller Tripping Breakers

[Fat Bastard]

And RCD's.
So... Went to fire up the new brew rig this arvo to begin the cleaning process, and it tripped the breakers and the RCD's.

I brew in a small courtyard between the house and the shed and draw power from both, and both sources have their own power boards and breakers, albeit coming from the same source on the street. The new rig powers the kettle and HX from one source, and the HLT from the other. Each system would power up ok until I connected the other, when it would trip both RCD's and breakers. The old rig would run fine, with the kettle and HX alternately running on one and the HLT on the other, so it's probably not the power source causing the issue (10A breaker in the shed, 20A on the house) but seemingly has something to do with the new controller, which is essentially the old controller x 3.

We had it running fine at work, so it's got me stuffed, and after a quick call to the guy that wired it for me left both of us none the wiser. I'll take it back to work on Monday, but pending that, do any of you clever electrical types have any idea of where to start looking?

Cheers,

FB

 

[Ducatiboy stu]

Initial surge current, inbalance in your house..... system.....

You say that you run parts of your system from 2 seperate supply boards.....am thinking you have your rig with a common earth so maybe running from 2 seperate supplies is causing earth loop currents which will upset both boards...

 

[Ducatiboy stu]

Will it run from just one source..ie house..( yes i know you tested it at work. )

I would be guessing that there is a potential difference between the earth pins from each supply you are using and that would be tripping your elcb on the boards.

 

[Fat Bastard]

Was just looking at the earths. They run to common ground, and when I hooked both sides up to the supply in the shed (elements and pumps off etc.) they tripped the RCD's but not the breaker. Which I suppose is an improvement!

Cheers!

FB

 

[Ducatiboy stu]

Sorry..cant really give an internet diagnosis...

 

[Fat Bastard]

Thought that might be the case, I've got it right in front of me and I can't make head nor tail of it. Mind you I'm no electrician! Seems very weird though.

You've given me a couple of clever sounding phrases to drop on Monday though, so at least you can say you've helped me appear smarter than I have any real claim to be!

Cheers!

FB

 

[Ducatiboy stu]

If it just trips a breaker but not elcb then it would point to an initial inrush current...but sounds a bit odd...if it trips an elcb it means there is some sort of earth potential or earth current....but then again you said it tripped an rcd....so diff problem again

 

[Nath151]

Have you got common neutrals in your panel as this will cause both elcb/rcd (same thing) to trip as there will be an imbalance on the neutral so the RCD thinks that it is going to earth and trips

Cheers
Nath

 

[QldKev]

Have you got common neutrals in your panel as this will cause both elcb/rcd (same thing) to trip as there will be an imbalance on the neutral so the RCD thinks that it is going to earth and trips

Cheers
Nath

This is my guess. If it is this, then your electrician should know better.


btw: what are the connections you use to crimp into the RCDs called

 

[Fat Bastard]

Looks like common neutrals in amongst all the spaghetti to me.

So, can I test this by removing the RCD's from the power in lines and see if it fires up ok? The spark from work suggested trying it last night, but I'm greatly afeared of something you can't see, and can kill you, so didn't try.

I guess if it didnt electrocute anyone at work during testing, it probably won't electrocute anyone now.

Cheers!
FB

 

[QldKev]

That pic is def common neutrals. Looking at the pic the left feed is onto 1 neutral, and the other 2 share a neutral link. If you remove the local RCD from the box, then the house RCDs may still be unhappy with it depending on how the power points you are using are wired up. With using power from the house and the shed I would guess that they have separate RCDs so you will still have the same issue.

Sack the sparky who wired it up and get someone else to do it.

ps. what are the crimps they used for pushing into the RCDs called?

 

[Fat Bastard]

Ferrules?

Looking at the terminal block he's got the neutrals going from the power supply in to, it looks like he's bridged them together, but then they go off separately to the terminal blocks for the neutrals for each element/PID/Pump circuit. Surely just removing the bridge would sort this out?

By the way, the breakers in the box are not the ones that are tripping, it's only the ones on the house/shed supplies and the in line safety thingoes that the external power plugs into before going to the brew controller.

The guy that wired it is only an apprentice, so I can't sack him, but I might be able to boot his tradesman up the clacker.

 

[QldKev]

I think it would be a matter of keeping the bridges just between the correct neutrals. So it's a matter of tracing them all and bridging them correctly. Shouldn't be a long job.

That was just a joke about saking them

 

[Ducatiboy stu]

If you have 2 different feeds into the unit then you dont want a common neutral.

Why does it have 2 feeds into the unit...?

 

[Fat Bastard]

I need the two feeds so I can draw from 2 10A supplies, didn't want to pay to get a big circuit put in atm, but that is something for the future.

Will take it back on Monday. I know he wanted to tidy the wiring up a bit better anyway, but I wanted to get it home to fiddle ASAP!

Promise I won't boot anyone up the arse, either!

 

[Ducatiboy stu]

Makes sense.

A common neutral is going to unbalance everything. Was thinking....a common earth could be an issue as well as the neutral is bonded to the earth in the main switchboard...

 

[MaltyHops]

ps. what are the crimps they used for pushing into the RCDs called?

bootlace ferrules ?

 

[Ducatiboy stu]

I would hope there insulated, because having exposed bare crimps is a bit of a no-no

 

[Pogierob]

Just had a quick look at your pick and BOOM I realised the problem..

the young fella has wired up the flux capacitor all wrong.

 

[booargy]

More than likely it could be that link screwed between the bottom 2 blue DIN rail connectors. I don't think you should take that out at all. In fact you should wait until monday until someone qualified can undo those 2 little screws and get rid of that little piece of metal joining them. He may also have to put a partition between or separate them.
Also get him to give you a cartoon of the wiring.