Help getting air compressor motor over "the hump" on generator power

[kinarfi]

Can I parallel two gennies? Does that even work or do they fight each other? I figure the frequency variance alone could be an issue?

YES! But you have to it manually, the easy way is to tie the grounds/neutrals together and put a light bulb or volt meter between the output of gen 1 and the output of gen 2 and adjust the speed of one or the other so they match as close as possible if possible. Watch the light or meter and it will on and off or swing from high to low as the two gens go in and out of sync, when the light goes out or voltage goes to 0, throw the switch to tie them together, then start your air compressor and once it's up and running, you can drop the smaller gen out.
I have done this many times and it can be done with gens of vastly different ratings. If you want to leave them both connected , the stronger gen will force the weaker one to follow, but it shouldn't cause any problems.
Jeff

 

[tcmtech]

Can I parallel two gennies? Does that even work or do they fight each other? I figure the frequency variance alone could be an issue?

Not reliably with common simple single phase units.

Just suck it up and put an engine on it and be done with it the right way. You'll be happier in the end for doing it.

 

[kinarfi]

I've been thinking about this and I think that if you just tie the two together, with a switch, they should load share quite well if they run the same voltage and frequency fairly closes, I think you could even add a single cylinder gen to aid a larger 2 cylinder gen to get it up and running, even if you flipped the switch while the phases were 180 out, it would only create a momentary load that would quickly correct itself, then start load sharing. Wish I had another gen to try this with, I'd say, go ahead and try it and then let us know how it worked out, I would choose 2 gens that are capable of running the compressor, but not starting it and hook them together to get it started, waiting patiently for your report!
Jeff

 

[JimB]

even if you flipped the switch while the phases were 180 out, it would only create a momentary load that would quickly correct itself

Look here:


JimB

 

[schmitt trigger]

Can I parallel two gennies? Does that even work or do they fight each other? I figure the frequency variance alone could be an issue?

Short answer no, unless you have a sure-fire way of tightly adjusting the output voltage, frequency and phase.
Otherwise, as you correctly mention, the two generators will fight each other. In a terrible way, I must add.

 

[tcmtech]

So meanwhile back here in reality,

No one but me has any problem with the idea of hauling two portable generators plus the compressor around, having to start both, synchronized them, then start the compressor, then shut one off only to have to come back to restart it again the next time the compressor cycles or leave both running?

Seriously, no one sees that as being at minimum a practicality of use issue compared to just putting a gas engine driven compressor that a person starts once and lets run until the job is done together that doesn't require any portable generator to have to follow it around let alone two of them?

 

[JimB]

So meanwhile back here in reality,

I agree, sometimes you just have to step back, take a look and ask yourself
"What the hell am I doing?" "This is madness!"

JimB

 

[fastline]

I was more or less asking to parallel gennies as an emergency tactic. Sounds debatable if it will work or not.

However i firmly agree on a gas powered comp. It makes the most sense by far in terms of fuel use size you name it. Not to mention a real 5hp comp is pretty worthy on most tools.