3phase machine goes BANG with a bit of smoke

[james king]

hello every one just wondering if u could give me possible solutions to why it went bang.

its a 3 phase machine pluged in to a socket. the socket goes straight back to board.

the machine is a compressor and is very old bout 30ish years!!!

i did NOT wire the sockets or the board. they called me out when there spark fitted the new CU. and left.

the bang happend when turing on the isoltor for the machine and that is wear the smoke came from.

i have not done any test yet eg continuty IR test as did not have time?

wondered what u thought it may be

 

[Darkwood]

Too many questions to ask for a definate answer but main question did it work before the new cu was fitted has anyone alterered the wiring where does the smoke come from- Motor??

 

[james king]

Too many questions to ask for a definate answer but main question did it work before the new cu was fitted has anyone alterered the wiring where does the smoke come from- Motor??

no smoke came from isolator. not sure if it worked b4 lets take it as a yes! it had rewire to yes people did altered it.

i take it from the point of smoke that the problam is in the isolator!

also a drill does not work and trips rcd evey time it turned on?

 

[stef]

Hi James,

check whether neutral and one phase aren't wired up correctly. It would mean that yoou 3 phase
application runs on two phases.

If the RCD tripps with the drill: check neutral, phases and earth, this must be a wiring fault.

 

[james king]

or a problam with the drill as it extreamy old! i will check all connections.

confused about the wiring of one phase and nutral? u mean they may be switched? eg

L1 brown
L2 blue (N)
L3 grey
N black

 

[stef]

Yes, something like that. It might be in the distribution board if that was the last thing which has
been changed. Another thing: are all the phases actually live? Canb you measure 415V between
each phase and neutral and earth?

 

[james king]

Yes, something like that. It might be in the distribution board if that was the last thing which has
been changed. Another thing: are all the phases actually live? Canb you measure 415V between
each phase and neutral and earth?

nope did not have time to make ne measurments as i had a job to look at 5 mins after!

i will deff do all test for every circuit. i had a quik look in the CU allrwires looked ok (for drill)

eg al were in correct place

l1 brown
l2 black
l3 grey. all nurtals were connected up as was earths....

so may be connection wrong in sockets.

Yes, something like that. It might be in the distribution board if that was the last thing which has
been changed. Another thing: are all the phases actually live? Canb you measure 415V between
each phase and neutral and earth?

nope did not have time to make ne measurments as i had a job to look at 5 mins after!

i will deff do all test for every circuit. i had a quik look in the CU allrwires looked ok (for drill)

eg al were in correct place

l1 brown
l2 black
l3 grey. all nurtals were connected up as was earths....

so may be connection wrong in sockets.

Yes, something like that. It might be in the distribution board if that was the last thing which has
been changed. Another thing: are all the phases actually live? Canb you measure 415V between
each phase and neutral and earth?

nope did not have time to make ne measurments as i had a job to look at 5 mins after!

i will deff do all test for every circuit. i had a quik look in the CU allrwires looked ok (for drill)

eg al were in correct place

l1 brown
l2 black
l3 grey. all nurtals were connected up as was earths....

so may be connection wrong in sockets.