SPP6 Start Capacitor on Cruisair 1600

[HopCar]

"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)."



How does this contradict what I said?
"The maximum start up current is referred to as "Locked Rotor Amps" (LRA) because at the first moment when the rotor is at standstill it appear as if it is locked."


I also said that I thought your generator should start an AC equipped with a Supco with an LRA of 59.


Sounds like we are in agreement on that. Maybe you do need a better generator.

[a64pilot]

A Honda's max continuous output I think is 13.3 amps, I only know about Honda's as I have two. Ganged together it's like being on shore power, but I did bite the bullet and buy and install a Nexgen 3.5. I'm unsure what I'll do With the two Honda's.
First find out with your ammeter how much current your AC pulls, don't forget the water pump, and see if that number is lower than your max continuous output of the generator. If it's not, then there is no point in continuing as the gen can't pull the load. I'd suspect even if it can, it will be screaming like it's going to blow up as it will be wide open.

Inverters that will act like a UPS or similar and provide AC power in excess to what the generator can make are available, question is can they respond quickly enough? I would think so as my Magnum will switch from shore to inverter literally in milliseconds.

What I did to run the Airconditioner on a Honda was to install a 5 KW one in the front Stateroom, a Honda will run that and charge the batteries, or run it without charging the batteries In Eco mode and do it quietly. It doesn't cool the boat, but it does make it so you can sleep.


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[Scout 30]

Northern Tool has the Honda generators on sale through then end of the year.

[Obi Wan]

Originally Posted by HopCar

How does this contradict what I said?
r.

I quoted what I thought it contradicted. You said that "LRA is actually a pretty good indicator of the power needed to get the compressor moving." Maybe I misunderstood you - I understood you saying that the full LRA is the amperage required to run the AC through the start. The website pointed out that it's generally about half of the LRA, which is what I guessed.

[Obi Wan]

Originally Posted by a64pilot

A Honda's max continuous output I think is 13.3 amps,

The Ryobi is 15.

Originally Posted by a64pilot

I did bite the bullet and buy and install a Nexgen 3.5. I'm unsure what I'll do With the two Honda's.

Nice - probably cost as much as my boat! If you want to donate the generators (or sell them cheap) I'm game!

[Obi Wan]

OK, I measured the current with a snap-loop ammeter. Just the compressor pulled 20 amps when the controller started it, which is less than I expected. Then it quickly dropped to around 9, which is the stated FLA. The fan only draws about an amp once it is started and running. The water pump doesn't kick in until after everything else is running, so is not so important, plus it's probably only a few amps.
I also verified this at the main AC power panel, so there was no other big draw adding to the AC.
So now I'm wondering if the Honda can surge to 20 amps. Apparently the Ryobi can't, or it's not quick enough, even with the auto-idle turned off. Wish I had a Honda to try out. I'm going to actually measure the Ryobi output once I get some time tomorrow now that I found my more accurate meter.
What I did do was order a huge inverter, something I wanted to do anyway. It's a 3000W low-frequency monster that surges to more than double that. My plan is to try running the AC off of that, with the generator or the engine alternator running to charge the batteries because they obviously wouldn't last long running the AC without almost as much juice running into them. The batteries/inverter then take care of the "surge" (plus I have an inverter for running other stuff like a microwave.
Has anyone tried this - i.e. the inverter with constant charging? Any pitfalls anyone can see?

[Sailmonkey]

You're going to need a charger capable of producing over 100 amps continuously to keep up with the inverter (closer to 120 with the pump and blower). Not counting effluence losses, etc.


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[a64pilot]

I don't know if a Honda can handle 20 for a very short while or not.
Yes, you can run your AC off of your inverter and theoretically keep the batteries up with the Alternator. I say theoretically as I tried just that today, but just for a short while. I was running the little AC and other loads and the alternator seemed to be only making about 50 amps, and the battery charge falling slightly to 98%. I didn't keep it up long enough to see if Alt output would rise to match or exceed draw.
Another thing you might could do is use the Generator to run a charger to charge the batteries while the inverter ran off of said batteries. That would be inefficient of course, but would give the generator a constant load while the batteries took the surges associated with the compressor starting. Need a big charger or course, maybe your inverter has one?

One thing I have noticed is that my alternator doesn't seem to make rated output, it seems to make 110 and then in a couple of minutes fall back to around 90 or so. I'm not running the engine at high RPM so alt fan speed is low of course, that and lower Alt RPM I believe makes it work harder, a double whammy heat wise. Its a 140 amp Alt.
I suspect not making rated output isn't uncommon for alternators.


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[HopCar]

Not all clamp on meters will accurately measure inrush current. Does your meter have an inrush button? If you didn't push the inrush button, your reading is probably low.

How and why to measure inrush current

I like your idea of using an inverter/charger in conjunction with the generator to run the air conditioner. I considered that but the hard start capacitor solved my problem and I didn't need to do it.

[Obi Wan]

Originally Posted by HopCar

Not all clamp on meters will accurately measure inrush current.

I thought about that. It's not a very high-dollar model so probably doesn't catch the real peak, although the meter does seem to respond quickly. I wouldn't be surprised if it's closer to a quick 30 amp surge. I just considered buying that Fluke 381 it showed, until I saw the $465 price tag.

It sure seemed like the SPP6 was the solution but it just didn't seem to make a difference. I'm going to go play around with it some more.

[Obi Wan]

Originally Posted by a64pilot

I don't know if a Honda can handle 20 for a very short while or not.

I wish someone out there would test their Honda so we can get the real answer. I just tested my Ryobi under controlled circumstances. It easily put out the rated 15 amps. And it surged up to around 20, where it kicked off, just like it's supposed to.

[sailorboy1]

Originally Posted by Obi Wan

I wish someone out there would test their Honda so we can get the real answer. I just tested my Ryobi under controlled circumstances. It easily put out the rated 15 amps. And it surged up to around 20, where it kicked off, just like it's supposed to.

I'm positive that if you do a site search you will find lots and lots of posts where someone has a Honda and it runs their AC (with and without that start pak). You will also find lots of posts where it wouldn't.

[Obi Wan]

OK, I went back to the boat and tested the current with the SPP6 back on. I actually saw greater compressor kick-in amps this time around than I did before (up around 25) - not sure why I saw lower before, maybe because the ambient temperature was colder before (80 degrees here in FL today). BUT, when I put the SPP6 on, the surge current went UP to over 30. I'm pretty sure they sold me a lemon.

Correct me if I'm wrong (all you EEs out there) but isn't a capacitor supposed to hold some voltage across the terminals if you take it out of the circuit (kind of the point)? I shorted the terminals after taking it off and there was not even a spark. Then I connected it again and took it off and the voltage was about 1.5

I'm sure if I could get a hard start capacitor that actually works, if it could keep the surge below 20, the Ryobi would do just fine - the running amps of the whole system was within it's capacity.

[Obi Wan]

Originally Posted by sailorboy1

I'm positive that if you do a site search you will find lots and lots of posts where someone has a Honda and it runs their AC (with and without that start pak). You will also find lots of posts where it wouldn't.

I did, thank you very much. I believe I said that early in this thread! Those are very subjective and it's kind of difficult to compare when someone said "it runs my AC great!" Maybe my Ryobi would run their AC great too.

What I didn't find was anyone say "I tested my Honda under controlled conditions and measure a sustained capacity of XX amps and it topped out at XX amps (like I did with the Ryobi).

That's a little more objective.

[a64pilot]

I think the hard start cap isn't just a cap. I believe it is a cap with a relay that connects and disconnects the cap, so you shouldn't be able to measure voltage in it.
Truthfully capacitors worry me, sort of treat them like a loaded gun as I have been bit in the past.
I am no EE by far, more of an internal error combustion sort of guy, but I'm pretty sure you can't leave a cap connected to the motor, but I can't explain why, it will cook something I believe.

I think the hard start cap lowers the actual inrush, but extends the time it occurs, so instead of a 50 amp inrush of a tiny fraction of a second, you get a 25 amp inrush for a second or so. If that is true, then it may be that your ammeter sees a higher number based on dwell time?
They are not a cure all, sort of a patch. What has me confused is why don't these AC's come with them already if they are so good?


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