| Home |
| Search |
| Today's Posts |
|
#10
Posted to alt.electronics,sci.electronics.design
|
|||
|
|||
generator problem
Jon wrote: "Michael A. Terrell" wrote in message ... Jon wrote: "Tim Wescott" wrote in message ... Jon wrote: I'm trying to wire a transfer circuit for a generator. The generator will be located in the barn. The electrical service is at the house. Two 120vac wires and a ground go to the barn. There is *one* unused wire from the house to the barn I can use for a signal circuit. When the power goes off at the house, I need to disconnect the service to prevent backfeed and activate for generator power to both the house and the barn. When the service power goes on I need to disconnect the generator to avoid damaging it and restore normal service to the house and the barn. I have, *one 240vac 60 amp dpdt mercury relay *two 120vac 60 amp 3pdt relays. Any ideas? Jon Giffen 1: Dig a trench, lay some cable, do it 'right'. 2: Do an enormous science project, and plan on buying more relays. One way I can think of to do this is to have the generator in the barn set up to disconnect the _barn_ on power loss, then start itself up. Power the one wire (against the 120V neutral reference) with what the generator produces. Then up in the house, use the absence of street power and the presence of generator power to switch off the street and onto the generator. You could complicate this further to automatically switch the generator off, but you're already looking at a mad scientists dream; were I to do this (I'd dig the @$%# trench) I'd just plan on _walking_ out to the barn after the street lights come on and shutting things down manually. If you're smart you'll check your local codes very carefully before proceeding -- home generator setups that inadvertently apply power back to the street can create very hazardous situations for line maintenance folks, and power companies generally take a dim view of people winging this sort of design. At the very least you'll need to use some power-company-approved switchover device that locks out the generator when you're on street power. -- Tim Wescott Control system and signal processing consulting www.wescottdesign.com Here's what I came up with: 120vac service lines 120vac | | | | | | signal line *------(coil A)------*--------------* | | | | | | --- --- | --- --- | | A | A | | | | | | | o--- house/barn -----o | | | | | | | --- --- | -/- -/- (coil B) | B | B | | | | | | | o-----generator------o --- - gnd coil A 240vac contacts 200 amps N.O. coil B 120vac contacts 100 amps N.C. I don't need to turn the generator on right away. I just want to take the guesswork out of turning the main breaker on and off every time the electric goes out. Then I don't want to have to test if the power goes back on and I can't tell. With this arrangement I can save trips back and forth to the house and barn. If this works when the power goes off all we need to do is go to the barn and fire up the generator. I guess I could also add a generator kill switch off of coil B. Let me know what you think. Where do I find the relays? Do you really thinK that the building inspector will let you connect a home brew transfer switch to the grid? The grid is home brew. Otherwise we wouldn't need a generator for power outages. The question is if I'm going to let their incompetence ruin my own grid... and they're not getting any of my electricity, either. THEIR incompetence? -- Greed is the root of all eBay. |
| Thread Tools | Search this Thread |
| Display Modes | |
|
|
Similar Threads
|
||||
| Thread | Forum | |||
| Problem Grounding a Generator | Electronics Repair | |||
| Odd problem with generator ..? | UK diy | |||
| generator problem(s) | UK diy | |||
| Honda Generator problem | Home Repair | |||
| gas generator problem | Home Repair | |||
Threaded Mode
