HELP! Duel Feed changeover unit for firemans lift and life saving services

[yackov]

hi everyone

has any one ever supplied a lift and emergency life services from one main supply permanent and the other a backup generator i have checked everything the changeover kicks in the generator when permanent supply fails but keeps running when the power is restored
i have checked everything and have no idea why it would do this. any ideas would help as i am losing the will to live being kept on hold by the manufacture

 

[UKMeterman]

It might not want to switch back till the supply has been proved to be stable..

 

[UKMeterman]

It may be an idea arrange for a buzzer and light to be activated somewhere public when this change over is active but not somewhere that would stop people useing the phone. There was one major UK data center had a power failure late on a Friday, UPS kicked in and the gensets took up the load. The load did not go back to public supply when restored, and the gensets ran out of fuel on Saturday afternoon, cue major shopping problems across the country...

 

[Darkwood]

Disregarding a possible issue with the unit.... if its functioning ok you may find the supply needs to be on for a set period before the gen will shut down also to consider is the supply has to sequence its phasing to match that of the supply otherwise your gen' will uproute and shoot through the wall, i would speak to the change-over panel manufacturers to enquire about a delay on re-established supply to unit shutting down.

 

[Engineer54]

As Darkwood has suggested get in touch with the change-over panel manufacturers, as it sounds very much like a component has failed, not allowing change-over to the prime supply. The only other thing i can think of why it's not changing back to prime power, is that the DNO (or others) have changed the order of phase sequence, which is a remote chance, but still a possibility!!!