Powering single phase motor from 3 phases

[Satrio88]

Hi, this might be an easy question, but i need to power a single phase motor situated about 300 meters away from my MCC. Do I just run 3 phases 415VAC cable to the motor in the field and just connect one live phase and the neutral to get the 240VAC? if that's the case then what do I need to do with the other remaining live wires at the motor location? OR do you I need to modify the MCC and run 240VAC from the MCC to the motor? beside the neutral is earthing cable needed at the pump too?

 

[Marvo]

I don't understand your question if earthing cable is required at the pump. If it's a steel wire armoured cable you're installing the cable armour needs to be earthed. Most pumps require a CPC (an earth) so I would provide one in the pump supply even if it's not used. Single phase pumps from an MCC are unusual because it makes load balancing and effective PFC difficult. I'm assuming this is a small pump? Personally I'd probably run a 4 wire and earth cable and double up on the 2 load wires also sleeving and ID'ing them appropriately to give a future option for any replacement pump in future to be 3-phase.

 

[mainline]

Hi, this might be an easy question, but i need to power a single phase motor situated about 300 meters away from my MCC. Do I just run 3 phases 415VAC cable to the motor in the field and just connect one live phase and the neutral to get the 240VAC? if that's the case then what do I need to do with the other remaining live wires at the motor location? OR do you I need to modify the MCC and run 240VAC from the MCC to the motor? beside the neutral is earthing cable needed at the pump too?

I can't see any point in running a 3 phase supply all the way to the motor when you can get away with a suitably sized 3 core swa
If you're going to maybe use a 3 phase motor in the future then as above

 

[Spoon]

Welcome to the forum mate.

Also the volt drop on 300 meters is going to be quite a bit, so from a cost point of view 3 cores will be a lot cheaper.

 

[Satrio88]

Thank you all for your prompt advice.

 

[brianmoooore]

Also the volt drop on 300 meters is going to be quite a bit, so from a cost point of view 3 cores will be a lot cheaper.

Cable for a 400 volt three phase motor will be cheaper still. Might be worth considering if a 3 phase pump is available.

 

[Satrio88]

Cable for a 400 volt three phase motor will be cheaper still. Might be worth considering if a 3 phase pump is available.

For the cable run, what is the allowed % voltage drop between the MCC and the pump?