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Electrical noise created by 3ph machine

Steve Phillips

Hello all

Life long sparky... semi-retired now, but working at a local workshop

The company had a local (rather shoddy) electrical company come in and re-supply a 3ph, 35A per phase painting/spray machine.    It was fed before and created flickering in the office fluorescent lights.

But, it still does it.  The fluorescent lights in the offices on the mezzanine nearby flicker when the machine pulls a high load.

It's fed from a sub DB that has a 125A, 25mm 3ph SWA supply (This run is considerable from the incomer - probably somewhere like 70M+.   

Machine MCB is 32A

They used 6mm 5 core SY cable (I would have gone 10mm) over a 25M run.  But they laid it on top of (not in) a 4" galv trunking with T&E inside.  Entirely possible the lighting feeds run within this trunking.

I may unstitch the cable and move it away from the trunking, but I am not entirely convinced that is the issue.

Any ideas on what to try?  

Personally, I would rewire the machine directly back to the incoming mains cupboard, but that is no easy task.

Parents
  • 0

    I have had a closer look at the lighting (I KNEW I would get roped into looking at the electrics here!)

    I am going to sort out the horror show that is the lighting.  Rewire it properly in conduit + plug-in roses and LED highbays.  Drop the circuits to 10A by adding two new circuits.

    Then the electrical company that just replaced the incoming DB and did a survey + certs (laughable), have agreed to then come and test it and sign it off.

    Thank you for everyone's advice

Reply
  • 0

    I have had a closer look at the lighting (I KNEW I would get roped into looking at the electrics here!)

    I am going to sort out the horror show that is the lighting.  Rewire it properly in conduit + plug-in roses and LED highbays.  Drop the circuits to 10A by adding two new circuits.

    Then the electrical company that just replaced the incoming DB and did a survey + certs (laughable), have agreed to then come and test it and sign it off.

    Thank you for everyone's advice

Children
  • 0 in reply to Steve Phillips

    Signing off somebody else's installation work on an EIC is a bit iffy. IMHO, you should issue an EIC and if the customer wants more paperwork, the other sparks can do an EICR. Frankly, it's nonsense.

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