Change over contactor

ktguk · Mar 6, 2012

Ive a customer with commercial units which are fed by a large diesel generator and this also feeds his house in the day (cheap/free electric) but when then generator turns off there is a change over switch in the house and then the house back feeds to the units for the lighting/access equipment, a lot of this has been bodged e.g. not working 100% and with frequent problems

So question is would this work with the phase failure option?

http://www.enbray.co.uk/ChangeoverContactors%20Datasheet.pdf

ProDave · Mar 7, 2012

I can see that working to switch the house from the genny to the mains when the genny shuts down.

But the bit I don't like the sound of it the house "back feeds the units for lighting / access equipment"

I suspect that part needs to be re designed as a separate function, possibly with a dedicated standby lighting circuit fed from the house.

I take it the house and units are adjacent so adding another cable run for the standby lighting should be possible.

What a strange arrangement. Is it REALLY cheaper to generate their own electricity with a diesel generator?

ktguk · Mar 7, 2012

The reason for the feed back for access/lighting is cost, it costs more to run the genny just to power the access/lighting (its using more energy just running the genny than its producing)

It doesnt really back feed it is through a sep core (4 core swa feed N&E, 1 DNO Live and 1 Gen Live)

It is very strange at first but the reason for the genny is the DNO wanted around 90k to install a 3ph supply that would run the park and the genny cost about 8-9k (85kw genny btw) and he is metering and billing the units