Panel problem

[rizla1990]

Well, I'd take your clamp meter with you to measure imbalance.

You could possibly measure what the ct is producing and measure that with a multimeter .

Thanks for the help, i am rather new to the commerical side of things so am still learning a lot as i go along. Will let you know what i find

 

[Bobster]

Quarry work is hardly commercial. There is a lot more than bs7671 you need to be aware of here. A lot is also statute law whereas bs7671 is not. So make sure you are absolutely sure you're meeting all requirements. As if it goes wrong you will soon be in a world of excrement.

Also worth a note no insurance will cover you if you've departed from some of these standards.

 

[Darkwood]

Are those the schematics at the bottom, you need to use them to trace the shunt trip circuit and what it is operated by, usually but not exclusively they look for a N/C loop and will trip the main switch if opened, it can be many things causing the intermitant tripping from corroded control connections, guard limits, O/L auxillaries etc etc.
You need to review and understand the wiring schematics, if unavailable it comes down to tracing and interpreting how the control system operates, failure to approach this the correct way will just cause wasted time and further confusion.
Judging by the colour code of the cable, the control will be AC possible 110v or 230v although the TX is too small to confirm.

 

[Darkwood]

Ill second Rob on this, in asking the question you really should be supervised when doing this work, this is not something you can take on when your short of other work, you need alot of experience in this sector or like Rob says, you may end up in deep doodi's, I did 15yrs in control and machinery before I classed myself as competent enough to hit it on my own, although i do cover a large variation of machinery, I'm still on a big learning curve even now after 28yrs.

 

[LeeH]

Like I said the shunt is clearly visible, upper right of the isolator near the 3 phase bus.

It may just need commissioning correctly.

 

[Darkwood]

Like I said the shunt is clearly visible, upper right of the isolator near the 3 phase bus.

It may just need commissioning correctly.

It is likely to be a shunt but to be open minded here, it may be one of many trips that can be fitted hence I motioned to look at the schematics which seem to be sat in the bottom.

 

[LeeH]

It is likely to be a shunt but to be open minded here, it may be one of many trips that can be fitted hence I motioned to look at the schematics which seem to be sat in the bottom.

With the CT connected (you can see the grey flex both ends) to the unit it has to be an RCD?

 

[Darkwood]

Bloody hell..had to expand that to super size to see it, yes it does look like the unit to the left of the 4 motor overloads is an eartheakage monitor, that been the case the red wire on the main switch will be as I suggested before just looking for a closed loop or it won't hold.
Are you veiwing this on a 42inch screen or what ?

 

[LeeH]

iPhone...

 

[Antony1]

The earth leakage relay is probably adjustable and probably didn't get set up right from the start, it may need adjusting now the motors are aging

 

[Bobster]

bare in mind that may be feasible in an ordinary installation.

This is supplying quarry pumping equipment

 

[rizla1990]

The earth leakage relay is probably adjustable and probably didn't get set up right from the start, it may need adjusting now the motors are aging

Sorry guys, forgot to let you know, turns out antony you are spot on, it was set quite low 0.5ma and 0.5 time delay. It has worked like this for around 10 months no problems. Have turned up to 1.5ma and 1.5 time delay and all is good. Thanks again everyone for the help

 

[Bobster]

1.5ma? You sure?

 

[LeeH]

Normally there is a multiplier. x1 x10 etc so maybe he's confused.

 

[Bobster]

Normally there is a multiplier. x1 x10 etc so maybe he's confused.

Exactly my thinking, guessing it's 150ma, if so, just broken M&Q regs.