SPP6 Start Capacitor on Cruisair 1600

[Obi Wan]

I read on this forum that using an SPP6 will/may allow a Honda 2000 generator to start the AC. I bought one and installed it across the compressor terminals at the run capacitor as shown on the schematic for the AC. It made absolutely no difference. The AC shuts down when the compressor kicks in using the generator (a Ryobi 2200) at exactly the same point with or without the SPP6.
The voltage when running is 300 volts across the compressor terminals.
Also, the Supco website talks about a PTC (positive temperature coefficient) relay wired in series with a start capacitor to cut it out of the circuit after the compressor starts, but I don't remember seeing that mentioned anywhere here.
I'm wondering if anyone has any wise words that may help.

[Sailmonkey]

How old is your AC?

And I hate to say it, but I've seen reviews of the honda lookalike generators, most of the others (Yamaha excepted) just couldn't pull off the starting current that the honda could.


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[Dsanduril]

You can use the PTC or a start relay, but something needs to take the start capacitor out of the circuit after the compressor starts.

There are two reasons the start capacitor can’t stay in the circuit full time.

1. The start winding of the compressor can’t carry such a heavy current continuously
without overheating and burning out.

2. The start capacitors are made very compact and would overheat in a short while
because they aren’t big enough to dissipate heat as rapidly as it’s generated.
The plastic casing on the start capacitor also plays a role in its tendency to overheat.
When a start capacitor does overheat, the little putty filled hole in the top of the
capacitor blows and all the fluid inside runs out, causing the capacitor to fail.

[a64pilot]

It may be that the current is still too high.
I have a brand new 16K of another manufacture, it's inrush current is darn near 50 amps. It is very short lived, but 50 amps is a heck of a lot.
I put the Supco hard start on it and it's inrush dropped to about half, or about 25 amps, but a little Honda couldn't handle 25 amps of course, so even with the hard start its too much. A soft start might get it started, but it may take too much current to run it.
A 16K AC will just about bust the little Honda's gut, even if you can get it started. My old AC pulled about 15 amps once started, and my new one pulls an amazingly low 11 amps, Honda can only make 13 continuously I believe.
I believe the relay is in the plastic cover of that cap, it's not just a capacitor or I don't think it is anyway.

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[Obi Wan]

Originally Posted by Sailmonkey

How old is your AC?

And I hate to say it, but I've seen reviews of the honda lookalike generators, most of the others (Yamaha excepted) just couldn't pull off the starting current that the honda could.

It's not a Honda lookalike, it's a Ryobi 2200. I'm quite happy with it and have tested the power output satisfactorily - at least to it's rated output and maybe a bit higher. Does the Honda go considerably above it's rated output? The AC is only a few years old.

[Obi Wan]

Originally Posted by a64pilot

It may be that the current is still too high.

I thought even if the current was still too high, at least I would notice a difference, like it would take longer to kick off with the start capacitor.

[Obi Wan]

Here's another thought - the Ryobi has a synching system to synch two of them together to double the output which I believe is also an option on the Honda. I don't really want to carry two generators. I know there are synchronizing inverters, which are probably really expensive. Does anyone know if it's possible to use the synchronizing circuit on the generator to synch a pure sine wave inverter to it? Or do the two generators have to talk to each other to synchronize? Obviously this is off topic from my original post but to the same end of getting my AC to work with my generator.

[Sailmonkey]

Originally Posted by Obi Wan

It's not a Honda lookalike, it's a Ryobi 2200. I'm quite happy with it and have tested the power output satisfactorily - at least to it's rated output and maybe a bit higher. Does the Honda go considerably above it's rated output? The AC is only a few years old.

A ryobi is a honda lookalike, there are lots of others too. But none had managed to work as well as the original.

It's the inrush that's killing you, even if you could get it started the running current of the AC and water pump may be too much to carry for an extended time.


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[Obi Wan]

The AC unit is an STX16-HV.

I wish I had a Honda 2000 handy to just test and see if it worked when the Ryobi does not. If it did, I would buy one that day.

As I said, I've been happy with the Ryobi so far. Quiet, powerful, light weight, starts easy, nice and portable with wheels and a pull-handle.

[HopCar]

it's possible that the starting load of your AC is just too much for your generator even with the Supco. Look for LRA on the compressor label. That stands for Locked Rotor Amps. This will give you an idea of how many amps it will take to get the compressor moving. My old 5k btu AC had an LRA of over thirty. I installed a Supco and was able to start it on a 1000 watt Honda. If the AC was larger, it wouldn't have worked. My gut feeling is that if your LRA is more than about 60 amps you won't get it started without a bigger generator even with a Supco on it.

[Obi Wan]

The LRA is 59 but I don't think it's fair to say that's what it's drawing when it starts because the rotor certainly isn't locked. Now it would be fair to say that the compressor start amps would be higher than the FLA, which is 9.4 but something less than the LRA. I would make an uninformed guess at around 50%, which seems logical.
I have read on here that someone else with my AC got it to work with the SPP6 and a Honda 2000.

[HopCar]

From what I can find LRA is actually a pretty good indicator of the power needed to get the compressor moving. Take a look at this: Sizing a Generator to Start Air Conditioner and Motors

I was able to start and run an air conditioner with an LRA about three times the generator rating by using a Supco. I would think your 2200 watt gen should start a 59 LRA air conditioner that is equipped with a Supco.

[redsky49]

Locked rotor amps is what you encounter when you hold firmly the blades of a fan and then turn it on. It is a critical failure amp draw, not (necessarily) a start-up amperage.

Doesn't Cruiseaire offer a soft start factory option?

[Obi Wan]

Originally Posted by redsky49

Doesn't Cruiseaire offer a soft start factory option?

I dont know. I guess I'll have to look into that - but I thought that was the point of the SPP6

[Obi Wan]

Originally Posted by HopCar

From what I can find LRA is actually a pretty good indicator of the power needed to get the compressor moving.

That's funny, the website you gave (which is a great reference, thank you) contradicted what you said and supported my guess (I was off by a percentage point).

"As the result, starting volt-amps could be 0.7*0.7=0.49 of nominal"

So LRA of (59 *.7)*(110v*.7) = 3180 watts. If the supco was working, I would also think the 2200 would be able to start the compressor.