Standby Generator 60Hz

Piratepete · Feb 4, 2011

Hallo
I'm rigging up a customer's 3Kw generator for standby use - essentially for floodlights and cameras around the house.
There is already a changeover switch with a supply cable, the installation is TT. I just need to connect that to a box containing an RCD and a plug.

The generator is of USA origin. I've removed the earth to the centre tap on the 115-0-115 winding and will connect one end to earth in the cable, but the output is at 60 Hz!

The customer has been running all his 50Hz power tools quite happily off this but I'm concerned about the effect on household appliances.

1. What appliances won't like 60Hz?
2. Am I right in saying that slowing the generator down to reduce the frequency will also reduce the output voltage?

ian.settle1 · Feb 4, 2011

Piratepete said:
Hallo
I'm rigging up a customer's 3Kw generator for standby use - essentially for floodlights and cameras around the house.
There is already a changeover switch with a supply cable, the installation is TT. I just need to connect that to a box containing an RCD and a plug.

The generator is of USA origin. I've removed the earth to the centre tap on the 115-0-115 winding and will connect one end to earth in the cable, but the output is at 60 Hz!

The customer has been running all his 50Hz power tools quite happily off this but I'm concerned about the effect on household appliances.

1. What appliances won't like 60Hz?
2. Am I right in saying that slowing the generator down to reduce the frequency will also reduce the output voltage?

1- Anything which is frequency dependent eg motors which will run faster on 60Hz
2- No it doesn't work that way, you will seriously damage the genny.

grantr37 · Feb 4, 2011

I take it the person moved here from America and is sufficiently worried about security lights etc to have planned ahead and decided to bring a generator over with them from the states, they have went to the bother of adding it to their CL (Container Load) from the states to get it shipped by Sea to the UK with their other things, or is it an old US Army surplus item from that company in Wales that deals in all that stuff? it is easy enough to get generators over here and they're not too expensive....

Piratepete · Feb 4, 2011

Generator looks fairly new (well couple of years old)- he has the manual. I'm trying to save him £600! judging by the lack of replies, I'm on dodgy ground.
I think I'll just have to say that if he powers anything other than incandescent lights and the kettle, it's at his own risk!

What I would like to know is whether it would damage electronics like low energy lights, TVs etc?

Marvo · Feb 4, 2011

I don't think the electronic appliance power supplies will like it. I would judge on a case by case basis, some power supplies are more universal than others. Some electronic items use the supply frequency to synchronise timer circuits so 60 hz on a 50hz system would reek havoc.

BlueToBits · Feb 4, 2011

If it's just for outside lights and security cameras I would have thought a change-over contactor on the one circuit would be easier with a wall mouted power inlet. If the supply failed the generator could feed this one circuit and not the rest of the house.

Engineer54 · Feb 4, 2011

To be on the safe side, i would check the spec's for those camera's and there monitor, they maybe 50/60, ...but then again, ...they may Not!!!

Piratepete · Feb 4, 2011

I have looked at seperating out the floods and cameras, but it's a major job as their supply points have been taken from various circuits and outhouse sub-boards.
It's probably cheaper to buy a 50Hz genny!

I'm sure that fridges won't like 60Hz either. They've got pretty crap motors so a 20% increase in speed.........!

Serious discussion with client required on Monday!

Thanks guys for all your thoughts.
Pete

Engineer54 · Feb 5, 2011

Sorry, ....I thought your original post was purely talking about supplying external flood lights and camera's.
You had better not hook that Genny up to supply the house, be it 50 or 60Hz, 3KW just ain't gonna cut it!! lol!!!

Also i was going to ask whats the total loading on these flood lights, as most Genny's don't like running for too long with under a 60/65% loading. They will actually start to destroy themselves!!! You normally have to size a Genny for the load it's going to carry....

Knobhead · Feb 5, 2011

60Hz will not go down well with motors, the speed and PF go haywire. Funny thing is going the opposite way doesn’t cause so many problems.

mnbs 4x4 · Feb 6, 2011

cant you fit a frequency converter to change from 60 to 50, i know they use them offshore for certain equipment , not sure of the costs though, might be cheaper with another gennie