three phase 2 pole rcd keeps tripping

[iceman]

hi chaps i had a call off a guy today frm his commercial warehouse, sayin his rcd keeps trippin, the rcd is on a 3 phase 2pole with 250A 30mA trip i tested it and all seems fine, but it in the office his running 12 pcs server plus all the usual kitchin appliences, this suggests the tripping possable overload , i reken he neds a higher rated rcd, i was thinkin mabe goto 300A with a 63mA trip wots ya thoughts on this

 

[Darkwood]

hi chaps i had a call off a guy today frm his commercial warehouse, sayin his rcd keeps trippin, the rcd is on a 3 phase 2pole with 250A 30mA trip i tested it and all seems fine, but it in the office his running 12 pcs server plus all the usual kitchin appliences, this suggests the tripping possable overload , i reken he neds a higher rated rcd, i was thinkin mabe goto 300A with a 63mA trip wots ya thoughts on this

Confused by the 3ph 2pole bit isnt it 3 or 4 pole? that aside I.T. equipment by the nature of the electronics dump waste electric to earth 'noise' the combination of all the servers is your obvious culprit here exceeding the operating value of your 30mA trip.
Fitting a 100mA should cure the problem but then you will have to fit individual rcbo's with 30mA trip where needed.
This is assuming they is no existing fault causing the rcd to trip in the first place.

 

[iceman]

it is 3 phase but the rcd is on 2 of the phases hence 2 pole , the sockets in question are on a ring final circuit, so you suggest i replace the rcd with a 100mA trip but wot rating would you use, and then replacing the the circuit breaker with an 30mA rcbo?

 

[Darkwood]

it is 3 phase but the rcd is on 2 of the phases hence 2 pole , the sockets in question are on a ring final circuit, so you suggest i replace the rcd with a 100mA trip but wot rating would you use, and then replacing the the circuit breaker with an 30mA rcbo?

My apologies never come across a 3ph 2pole, without knowing the dist board loading etc i still doubt its an overload problem so fitting the same rating should be fine but clamp the dist board supply to confirm this and as i mentioned before you need to have individual 30mA protection but this will only bring the problem to this rcbo so possible new circuit design to have the servers over different circuits thus reducing the accumulative leak on any one rcd.