Connect 120v Gen to 50Amp ATS?

Depends on the genset.
Some gensets have a 120/120 neutral and ground twist lock setup.
Others have a 30 three wire 120 volt twist lock receptacle.

I'm interested in the electrical connection, not the mechanical plug/socket connection. The 50A ATS has two input hot leads at its gen input, L1 and L2. The 120v gen has only one hot lead at its output (which could be connected to multiple receptacles). Is that single gen hot lead normally electrically connected to short across both L1 and L2 at the ATS input?

if the generator has a single output then yes generator input L1 & L2 will be bonded on the TS.

You would need to get the correct adapter to go from the three wire 120 output to go to the rig's 50 amp 120/240 connector. Yes L1 and L2 are connected together.

are you 'wondering' about the built in generator is wired in a 50 amp coach ?

that generator has two outputs, and is wired to the genset input exactly like the
50amp shore cord is wired on its set of inputs

NO,, there is no shorting or connecting the two hot wires

that only occurs in a 50a female to 30a male dog bone adapter for shore power use

most RV generators have two 120v outputs
even a 4kw genny in an RV with a 30amp shore cord and breakers

one input will go directly to the house circuits
the other will handle the A/C unit and maybe minor bedroom or bath
so the house circuit can handle the kitchen, MW , fridge etc

time2roll wrote:
if the generator has a single output then yes generator input L1 & L2 will be bonded on the TS.

X2
Generator HOT goes to 'gen input L1' with a jumper from 'gen input L1 to L2'


When generator is source of AC Power.....both L1 & L2 are energized so Main Panel is hot on both busses.

Otherwise only 1/2 of main panel would be hot when on gen.

MrWizard wrote:
are you 'wondering' about the built in generator is wired in a 50 amp coach ?

that generator has two outputs, and is wired to the genset input exactly like the
50amp shore cord is wired on its set of inputs

NO,, there is no shorting or connecting the two hot wires

that only occurs in a 50a female to 30a male dog bone adapter for shore power use

most RV generators have two 120v outputs
even a 4kw genny in an RV with a 30amp shore cord and breakers

one input will go directly to the house circuits
the other will handle the A/C unit and maybe minor bedroom or bath
so the house circuit can handle the kitchen, MW , fridge etc

I was wondering about generators like an Onan HKAK 8KW. It is inverter based and produces single phase 120v power. It doesn't matter how many physical outlets or receptacles it has, electrically, it has only one hot lead. My older Onan which produces 240v has L1 and L2 connected to the matching leads on the ATS.

The manual I read has two 30 or 35 amp breakers so while it is single phase each pole may get connected to each side.

time2roll wrote:
The manual I read has two 30 or 35 amp breakers so while it is single phase each pole may get connected to each side.

Yes! I suspect that's exactly what I will find. I was thinking about the 4.0CCK Onan 120 v gen in our first coach when I asked the Q. I had forgotten that I'd read in the HKAK manual that although it was single phase 120v, it had a split output. The CCK would be bridged across L1 L2 in that application (it has only a single output and no breaker).

That means that one could only pull a max of 33 A on each of the 50A branches even though the HKAK gen is rated at 66A. One couldn't pull a full 50 A on either branch if one needed to.

The 2800 watt inverter in the all-electric design would probably be bridged across L1 L2, since it isn't a split output.

Thanks to all for the comments.

DryCamper11 wrote:
I'm interested in the electrical connection, not the mechanical plug/socket connection.

You can't really talk about one without the other, or shouldn't, because the physical type of plug/socket MEANS something about the configuration and capacity.

IF your gen has only one 120 output, then it probably doesn't have the capacity to run both legs of your 120 service in the RV.

You might be able to get away with it by severely restricting your usage inside......but it really isn't a good idea.

It is perfectly OK, however, to feed ONE leg off the generator.