Field wiring bypassing terminal blocks after incident ( Industrial Board in EU)

[tintin75]

Dear all,

A newly commissioned cubicle had some terminals burn and cables melt on the LV supply (seemingly due to faulty connection at push-in terminals)

The contractor simply cut back the damaged field cable and terminated the wires directly. In the case of the active, fitting it into a circuit-breaker terminal that already accommadates a busbar (schneider busbar a9xph212).

The quoted thread was interesting but I don't know if under IEC rules, field cables must terminate into designated terminals (?)

I requested the terminals be replaced and the cabling to be restored as per drawing but the contractor prefers to update the drawing to represent the mod.

I don't like that the active is just squashed in with a busbar I think this could present its own problems.

I have not convinced anyone that the installation should be restored to original. It is of course functional and perhaps I should leave it there... but do you know of any wiring rules that require terminals for field cables (as opposed to it being just convenient for installation)?


thread248-502613

 

[che12345]

I have the following opinion for your consideration
"#1. ..newly commissioned cubicle had some terminals burn and cables melt on the, LV supply (seemingly due to faulty connection at push-in terminals)".
As there are some (not isolated case), the workmanship is questionable. Check and recheck ALL the terminals. Keep extra supervision for another at least six months.
" #2. ..The contractor simply cut back the damaged field cable and terminated the wires directly. In the case of the active, fitting it into a circuit-breaker terminal that already accommadates a busbar (schneider busbar a9xph212)"
I am of the opinion acceptable for practical reasons.

" #3. quoted thread was interesting but I don't know if under IEC rules, field cables must terminate into designated terminals (?)"
In general, any terminal block design with correct current and voltage rating are acceptable.
" #4. I requested the terminals be replaced and the cabling to be restored as per drawing but the contractor prefers to update the drawing to represent the mod".
If the terminals are of correct current and voltage rating and there is NO sign of over-heating, the contractor preference is acceptable; for practical reasons. The more important is the functionality. The drawing usually does NOT define the installation method on how the terminations shall be made.
Che Kuan Yau (Singapore)

 

[waross]

Bid documents?
Contract documents?
Inform the contractor that you will be requesting the manufacturer to make repairs and will be back charging the contractor.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[FacEngrPE]

Repairs not in accordance with the original design void the ITL (UL/CSA/etc) certification. I agree with waross, the vendor should be required to resolve as a warranty claim in a manner that the ITL certification remains intact.