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mattd
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# Posted: 23 Jun 2024 10:57pm
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I put the Supco hard start cap on my camper in hopes of running the ac with the 2200w inv gen.
It’s still tripping the gen breaker. Have it on the Herm and Common spades. And it fails right away once the compressor tries to kick on.
I was under the impression it was a pretty good bet it would work. Not so? Or do I have something else I should try?
It is a bit older hard start. Bought it for the cabin window unit a few years ago, but the gen powers that 8k btu just fine. So it’s been sitting around the garage the whole time.
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gcrank1
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# Posted: 24 Jun 2024 12:55am - Edited by: gcrank1
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My guess is the gen just doesn't have enough beans. Are you running on gasoline or propane (lp has less energy)?
And don't have it set on Eco but running full on and warmed up.
Next would be trying it with a 2500w (got a friend with one?), then a 3000w.
Fwiw, I got my old 5000w window ac unit going by manually switching the ac off when the gen was slowing down but before it tripped then on again once the rpms came back up (gotta be quick). Once the compressor spooled up it ran fine. I think it would keep running to cool the cabin until it reached the set temp and went to cycling off/on. By then the cabin would be cool enough to turn the ac off.
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mattd
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# Posted: 24 Jun 2024 11:51pm
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Gas power on full power mode, not eco.
I just have a wall thermostat and it takes about 2.5 min after turning it on for the compressor to kick in. So no tricking the system.
For $15 bucks I bought a new one to test. Will test tmrw.
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mattd
Member
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# Posted: 25 Jun 2024 12:23am
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The next option will be to run 2 2200w gens in parallel.
Is that likely to run the compressor? Is that like having 4400w available?
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travellerw
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# Posted: 25 Jun 2024 12:35am
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My suggestion would be to ensure the fan is running before the compressor kicks in. Some ACs will try to start both at the same time and generators can't deal with the inrush of both the compressor or fan.
If that doesn't work, then your only option is a new AC or a soft start unit (about $300 USD). Soft starts do work and I have seen a honda 2000 start a 13.5K BTU unit.
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mattd
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# Posted: 25 Jun 2024 11:08pm
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Got the new hard start cap installed, and same thing. Tried it a few diff ways; switched the wires I attached to the factory cap, tried diff gen outlets, etc.
Still didn’t work.
Plugged it into the house to confirm the ac still works (it did back in March when we last ran it, and is only a few years old), it it still works fine.
Shut it all down and plugged back into gen and it works! Maybe just had to get the bearings warmed up.
It is running the gen at an elevated rpm. With just the fan running it idles quietly. I figured there’d be an rpm surge at compressor startup and then Slow down some. It’s not slowing down.
The immediate need for this weekend is at a friends prop where he has a larger gen. So worst case we get it cooled off with that and then run it for a bit on my small one.
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gcrank1
Member
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# Posted: 25 Jun 2024 11:20pm
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Be aware that running a power device at the upper reaches of its band continuously is not optimum. That is, most stuff likes to run at about 3/4 of the band with stretches to the top now and then.
No idea where your unit falls in this, but most likely the bigger gen would be in its happy place.
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mattd
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# Posted: 25 Jun 2024 11:30pm
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Found the ad from when I bought it 6 yrs ago and it says as quite as 52db.
My phone db meter says 92db. Where’s that rank for a 2200w inv gen? It’s loud but not getting ready to explode loud.
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mattd
Member
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# Posted: 25 Jun 2024 11:33pm
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First video on YouTube is my exact gen. He’s running 82db in eco mode, no load.
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gcrank1
Member
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# Posted: 26 Jun 2024 12:43am
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Beware advertising hipe vs reality.
Ive never checked my Lil' Champ 1750/2000peak inv/gen but it is so much quieter than anything else that I don't need to.
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ICC
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# Posted: 26 Jun 2024 12:50am
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Quoting: mattd Found the ad from when I bought it 6 yrs ago and it says as quite as 52db.
At what distance between the genny and the decibel meter?
I assume the "as quiet as" means at idle
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ICC
Member
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# Posted: 26 Jun 2024 12:53am
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Honda uses 7 metres and measured 90 degrees out grom from the control panel
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mattd
Member
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# Posted: 26 Jun 2024 12:57am - Edited by: mattd
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I don’t put any stock into the ad. A guy on YouTube was using a real meter and measured 82db right next to it in eco mode with no load.
He measured 94 I think with a 1500w heat gun running.
My phone measured 92-98db. That was continuous, not at comp start up.
So I’m guessing I’m a bit over 1500w to run the comp on an 1800 running watt gen.
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ICC
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# Posted: 26 Jun 2024 01:23am
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7 meters or 21 feet is the std industry distance so if the guy is measuring right by the machine it is somewhat meaningless.
For each doubling of distance from a point source, the decibel level decreases by approximately 6 dB
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gcrank1
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# Posted: 26 Jun 2024 03:32am
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I don't get the correlation between Db and Watts
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ICC
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# Posted: 26 Jun 2024 04:13am
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Quoting: gcrank1 I don't get the correlation between Db and Watts
An increase in watts will be accompanied by an increase in noise, as would be expected, but not really meaningful.
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gcrank1
Member
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# Posted: 26 Jun 2024 12:06pm
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Yeh, I Get that....and agree not very meaningful outside of subjective. Pretty much like the Harley boys around here that think straight pipes give em more power.
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mattd
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# Posted: 28 Jun 2024 03:18am
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I ordered some parallel cables off Amazon and a buddy let me borrow his Honda 2200w.
The cables that came were not the same from the add, so know time to test parallel gens before this weekends trip.
But his Honda does start and run my ac. Every time. But also every time there seemed to be a power surge 10-15min into ac running that over loaded the Honda.
The thermo was set to 66, and it never got that cold, so the compressor shouldn’t have stopped turning. Any idea what that surge is? Do compressors ramp up at some point?
So from idle to peak compressor start up it has enough juice, but ac running at 1500+w it can’t meet the demands of whatever that surge is.
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gcrank1
Member
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# Posted: 28 Jun 2024 03:30pm
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Turn the stat down?
Fwiw
1500w divided by 120vac equals 12.5amps + whatever extra is there due to inefficiencies (beyond the simple math)
The circuit breaker is likely for the 15amp outlets and you are on, or over the edge.
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