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Any Pointers on electrical layout for a fabrication rig
Former Community Member
Trying to find the best approach to this problem has the cable trays between the sockets of the units will not cater for large cables above 25mm2 so was looking at having to change the design from a looping cabling system between Main sockets on each floor there are 4 floors in total on the rig to each Power Cluster.So that each Power Cluster have there own Power Supply cable going to them individually so we can look at cutting down the size of cabling to fit the cable trays.But to do this i'm after some electrical layout ideas from the Forum.The starting point of the electrical layout are 3 125A Sockets (ie.400v,230v & 115v) which have an interconnection at two ends (ie Left Side and Right Side) so there is a need for a change-over switch.Then from there on looking at adding a large distribution box for the individual cables to connect to the various sockets of the Power Cluster.
So this is a mobile 4 stage building - like a stack of portacabins as a mobile worklshop ?
The biggest problem with plugging into supplies unknown is verifying that the earth impedance is OK to clear the fault protection, the fault protection is correct, and also, in the case of the 3 phase extension leads case, that the phase rotation and L_N polarity is correct.
I have some experience of military shelter sort of things that can be dropped anywhere, and in those there is normally a single box where power is marshaled before going out to the equipment, and at this point there are phase rotation indicators, N-E offset voltage trips, and an an earth fault relay . And an all pole isolator.
Power of opportunity is just that, and if you have no idea how it is being connected - and in some parts of the world it could look like jump leads from overhead lines, you have to be robust against all credible faults before you flick the big switch and connect your own expensive loads.
Equally if it is being installed in the UK as a semi-static site, it is not unreasonable to ask for an electrician to hard wire your tails into the local distribution board - after all very few places will have a couple of unused 125A sockets in a handy location, so if they are fitting them specially , then a box with some terminals for hard wiring is probably easier. - that may be as basic as line taps on a paxolin panel or henley blocks, but l inside a large metal box rigidly mounted to the wall or a pillar.
So this is a mobile 4 stage building - like a stack of portacabins as a mobile worklshop ?
The biggest problem with plugging into supplies unknown is verifying that the earth impedance is OK to clear the fault protection, the fault protection is correct, and also, in the case of the 3 phase extension leads case, that the phase rotation and L_N polarity is correct.
I have some experience of military shelter sort of things that can be dropped anywhere, and in those there is normally a single box where power is marshaled before going out to the equipment, and at this point there are phase rotation indicators, N-E offset voltage trips, and an an earth fault relay . And an all pole isolator.
Power of opportunity is just that, and if you have no idea how it is being connected - and in some parts of the world it could look like jump leads from overhead lines, you have to be robust against all credible faults before you flick the big switch and connect your own expensive loads.
Equally if it is being installed in the UK as a semi-static site, it is not unreasonable to ask for an electrician to hard wire your tails into the local distribution board - after all very few places will have a couple of unused 125A sockets in a handy location, so if they are fitting them specially , then a box with some terminals for hard wiring is probably easier. - that may be as basic as line taps on a paxolin panel or henley blocks, but l inside a large metal box rigidly mounted to the wall or a pillar.
