Generator Wiring Question

[Paul]

Generator Wiring Question

Generator 120/240 volt three wire with ground
                   or
120 volt two wire with ground is the question.

We have two roof top air conditioners, microwave, 65 amp converter( for 12 Volt system) TV /  CD player
When I start the microwave with the air conditioners on the smart transfer switch turns off.
We just added Mangum 4000 Watt inverter that also turns off transfer switch.

The generator is wired for 120/240 and when new the voltage read 122 volts on both lines.
Now it is only 117/116 volts per line

The transfer switch is a Surge Guard model 40250 RV Power Monitor

[Jriddle]

Does the transfer switch sent the neutral to the power source?

John

[bevans6]

I don't understand your problem.  Transfer switches typically don't turn off, they switch between sources of power.  A Magnum 4024 can supply around 30 - 32 amps at 120 volts, so two AC's and a microwave is too much for it to handle.  It will drop out and cause the transfer switch to look for another source of power.  You don't mention the power rating of the generator but it is probably having it's output pushed down too.  

Edit - I had another thought.  I had an issue with getting the AC to turn on.  If I was on the inverter, it would turn on fine.  If I was on a cord or the generator, it wouldn't turn on, the Magnum would start trying to switch in and out with it's transfer switch.  The problem was voltage drop on the surge load as the AC motor started.  I reset the Magnum low AC voltage setting to a fairly low setting, I think around 95 volts, and it stopped trying to protect things as the motor started.

Brian

Brian

[Paul]

This only happens when on generator power.

The air conditioners do not work on inverter power only on shore or generator power

The trouble is with the  generator getting out of balance and shut down on low or high
voltage.

The question is generator wiring
Generator 120/240 volt three wire with ground
                   or
120 volt two wire with ground is the question.



      Thanks John & Brian
         Paul

[digesterman]

Paul what is the wiring now on the generator? It would be a waste if it were to be a 240 wired generator and you only utilized one lag or one 120 winding (sounds like you have two 120 windings). Use both 120 wires to two different loads, of course the ground AND the neutral if so equipped , some older units didn't have a neutral just 120, 120, ground, not so good on electronics. You can always run the two 120's to a 240 outlet for whatever. On some generators if you do not use the neutral your 120 windings can give you unequal output, I.e. 90 volts on one and 140 on the other, again guaranteed to take out electronic equipment.

[belfert]

Some generators can be wired for either 110/220 or just straight 110.  My Powertech can do either and Powertech recommends doing 110 only for generators under 12,000 watts unless you must have 220 volts.

[Oonrahnjay]

Paul what is the wiring now on the generator? It would be a waste if it were to be a 240 wired generator and you only utilized one lag or one 120 winding (sounds like you have two 120 windings). Use both 120 wires to two different loads, of course the ground AND the neutral if so equipped , some older units didn't have a neutral just 120, 120, ground, not so good on electronics. You can always run the two 120's to a 240 outlet for whatever. On some generators if you do not use the neutral your 120 windings can give you unequal output, I.e. 90 volts on one and 140 on the other, again guaranteed to take out electronic equipment.

     Yes, good info here, but there's also the issue of 240 leg balancing.  If you're running a generator that's making 240, you should be using about the same wattage on each leg; otherwise, you have a LOT of juice going down the neutral.  Being out of balance is one of the big reasons (not the only reason but probably the biggest one) for the unequal output that d-man is describing above.

[Paul]

This is the data for my transfer switch

http://trci.net/products/surge-guard-rv/transfer-switches/50a-plus-hardwire-rvc