Temp Generated supply for office

ohlins · Dec 30, 2009

Hi guys,
Ive been asked by one of my good customers if it is possible to rig up a temp supply to feed there small office and workshop next week as the mains will be off for one whole day.They have a large (not seen) generator on site.Please could i have your thoughts on this,the generator is a stand alone bit of kit and is not connected at all at present.What would you guys do regards connection/protection etc.
Many thanks

Guest123 · Dec 30, 2009

Hi.

You could offer him the option of installing a mains changeover switch to future proof the job should the power ever go off for any length of time again.

Obviously there is the cost to consider but I'm sure the cost of you doing the job right first time would be off set by him losing a days production from his workshop.

It's probably the easiest way of connecting in the geney too, all that would be needed is an appliance inlet next to the changeover switch and extension lead (both rated accordingly) out to the geney, depending on size of geney and if there are socket outlets or direct connections on it.

Would need some more info on the size of the geney and setup before I could comment on earthing arrangements.

More than likely need to install a rod adjacent to the geney to bond frame to earth unless E+N are linked at the star point of the winding/alternator in which case the geney RCD would clear any fault on supply cable, you could do a continuity test to confirm this at the geney outlets.

HTH.

boatnik1 · Dec 30, 2009

Alternatives: either single or three phase. A change over switch between meter output and CU/DB, either 2 pole or 4. to give alternative mains or Gen. in and CU/DB out can be left in position for future use and is fairly fool proof.

The alternative and hairy not approved and not advisable way is to connect into the switched side of the CU/DB with the switch off but you can be sure that some clot will turn the switch on and cause a conflict with the incoming mains.