SPP6 Start Capacitor on Cruisair 1600

[a64pilot]

I think your best bet is the inverter running the AC, and your generator running a battery charger.
It is sort of Rube Goldberg and will be inefficient. I'd think you would need at least a 100 amp charger, actually more if your AC pulls 10 amps. I think it will take pretty much all of your Ryobi's 15 amps to do it too with the inefficiencies involved, but at least the generator will see a steady load.
My Magnum will let me tell it the max AC current the shore power is capable of, when the AC load hits that number, the charger backs off to keep from exceeding it, maybe yours can do that?


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[sailorboy1]

Originally Posted by 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.

Where did you measure the amps in relation to the capacitor? It's function is basically to supply extra amps to the compressor on start-up by discharging.

I'm not going to go back a pick the thread apart. But have you tried to start and run the unit while on shore power? If you did did you measure the amps then?

Assuming your system will start; if it wouldn't start with the potable gen then the capacitor isn't supplying enough power. Get a larger capacitor!

[Obi Wan]

Originally Posted by 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.

It does - see: Supco

I also charged it quickly (less than a second) after it had cooled off (so the relay should have closed) and measured it - still only 1.5 volts. Just saying...

Originally Posted by a64pilot

Truthfully capacitors worry me, sort of treat them like a loaded gun as I have been bit in the past.

Yes, good advice. I was careful. They can pack quite a wallop.

Originally Posted by a64pilot

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.

This explains it very well. It cooks both the motor and the capacitor:

http://www.supco.com/images/pdfs/AC%...%20Booklet.pdf

Originally Posted by a64pilot

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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It doesn't lower the inrush required by the motor, it lowers the inrush on the supply line in because it is supplying some of the required current, which it can do because it has the "capacity" to do that for a very short time (all that's required to overcome the initial requirements to start up the compressor). What you say is interesting though and feasible if it actually did extend the time, and would make sense if that was so, but I don't think that is the case.

[Obi Wan]

Originally Posted by sailorboy1

Where did you measure the amps in relation to the capacitor? It's function is basically to supply extra amps to the compressor on start-up by discharging.

I'm not going to go back a pick the thread apart. But have you tried to start and run the unit while on shore power? If you did did you measure the amps then?

Assuming your system will start; if it wouldn't start with the potable gen then the capacitor isn't supplying enough power. Get a larger capacitor!

Yes of course I made these measurements with shore power.

You are at least partially wrong, or at least misleading, though, in saying that the capacitor supplies "extra" amps. The motor draws X-number of amps to start, assuming the circuit has the capacity to supply all the needed amperage, which it should on shore power (ideally). It can not supply any more than the motor requires in this ideal case. So on shore power, the capacitor doesn't supply extra amps, it supplies some of the required amps, thereby reducing the load on the supply line. Of course, that's ideally, and I would say that there is probably a voltage drop on the shore circuit when the compressor starts, limiting the amps to below what the motor actually requires. The more the voltage drops on the supply line, the more amps the capacitor provides, in relation to what's required by the motor. So from that perspective, it does supply "extra" amps . I guess that's why these capacitors are used a lot because so many of the circuits can't supply the required amps.

Of course, I'm no EE either, but that's what I remember form my electrics courses.

But you make a good point in that I measured between the capacitor and the motor. So if my supply line, even on shore power, can't supply the required amps, that might explain why the current went up with the SPP6. So maybe it does work. I don't know at this point. But it still didn't work with the generator. And I still think there should be a voltage across the capacitor with the relay closed.

And there was another thread on here (yes I searched before starting this thread) that said someone with my exact AC unit, and a Honda 2000 generator, and an SPP6, worked. That's why I ordered the SPP6 and bought the generator. If the Honda is rated at 12.5 amps, and the Ryobi at 15 amps (which I verified), my system should work, assuming the SPP6 actually works. That's why I want to know if these miracle Honda generators are somehow producing quite a bit more than their rated amps. Which it sure would be nice if someone would verify, empirically.

[sailorboy1]

Well I know when it is time to just stop reading a thread.

[Obi Wan]

Originally Posted by sailorboy1

Well I know when it is time to just stop reading a thread.

Too bad. You've been such a big help...

[Obi Wan]

If anyone is interested (surely not sailorboy), I have an update. I tried another SPP6 and it was identical to the first so there must not have been a problem with the first. I tried both of them in parallel to "boost" it even more and noticed no difference.

My next step is to contact Cruisair and see what they say. I will also try an inverter.

Also, I did get a chance to test out a Honda 2000. Turns out my slip neighbor had one and let me try it. It did not start the AC either, though it seemed (just an impression) to be slightly more up to the task than the Ryobi (my impression was that it responded quicker to the demand for power).

That being said, I did test it empirically right next to the Ryobi. The Honda, though rated at 13.3 amps I believe, easily produced a steady 15 amps. I tested with an electric heater and a few power tools using a clamp-on ammeter. It surged up to 20 amps (I saw 22 a few moments). So it produced (above it's stated output) about on par with the Ryobi 2200 .

My impression was that the Honda ran slightly (ever so slightly) quieter than the Ryobi, ran a little smoother and was slightly smaller. It seemed slightly heavier though the specs show it being slightly lighter. It's a tough call between the two - I got my Ryobi for $350, so, though I'd rather have the Honda, It's a pretty big jump in price. Plus I love the wheels on the Ryobi. Of course, if you have to rely on one in the middle of the sea, I'd go with the Honda.

[boat4life]

Hi Obi Wan, I have a similar issue with my Cruisair SX10-r6 air conditioner. I installed the SPP6 per instructions and did not notice any difference. Were you able to get your AC unit to work?
Wonder what Cruisair recommended? I tried contacting them but they aren't being very helpful.
Let me know if you'd rather PM instead.
Thanks

[Obi Wan]

First, I bit the bullet and installed a Victron Multiplus 12-3000-50 inverter. It combines generator power with the inverter power from the battery bank. I added two more batteries to my bank (total 5) with monster cables). With one Honda 2000, the A/C STILL DOESN'T start on generator power. I suppose with a bank of 10 batteries it might work. But I don't have the room or the inclination for that. Now I have a very expensive way to run my microwave.

So my solution for the A/C was to also start the diesel motor and run up the rpms so the alternator is pumping in about 60 amps to the batteries (14 volts of course), THEN the A/C would start. So then I shut down the diesel, and turn the AC all the way down so it won't cycle, because if it did, it would overload the system again. Then I run it as long as I can and get it good and cold. But this is not effective for letting it run all night because then it cycles. If I want to do that then I have to take TWO Honda 2000s and connect them together. Then it starts the AC fine without the diesel running.

I wish I had a smaller AC (or at least one with a soft-start compressor). The one I have is nice at a dock with shore power but a royal pain out on the water. Cruisair wasn't helpful for me either.

[boat4life]

Obi Wan,
That's some serious setup!
So, I had a marina friend who is an expert in HVAC help me out. We ended up isolating the Compressor from the entire system. Removed the wires that were currently attached to the C, R, and S (Compressor, Run, Start) pig tails. We then connected the SPP6 to the compressor. Used a power cord and rigged it on there. I don't have the correct schematics to explain it since he had created the power cord to capacitor to terminal connections.
We did a test run with shore power to see if the compressor would kick on. It worked! AC and Water Pump worked as well. So there was no issue with the compressor and SPP6 Capacitor.
We then tried it on the Honda 2000 to power on the compressor. It fired right up. We then tested the AC Fan and Water pump separately without compressor. It worked. Then we left the Fan and Water pump running, and
then plugged in the compressor. Everything worked!

Conclusion is that there may be something wrong with my Start Relay Box or Start Capacitor. The in rush amps/volts is not getting to the compressor when everything is installed according to the manual (it works on shore power but not on any generator). So, the plan will be to rig up a switch that will control the on/off of the compressor. It will be isolated from the entire system.
Side Note: I have a Westinghouse WH2000ixlt. I was not successful powering up the compressor with it, which was odd since the specifications are the same as the Honda. (It maybe the power cord we used to connect to the compressor, very thin wires. Will have to get a thicker power cord) I will have to try once more Thursday, let everything settle. If it does not work, then its true, "you get what you pay for"...Honda is a beast!

Boat4life

[Obi Wan]

Originally Posted by boat4life

Conclusion is that there may be something wrong with my Start Relay Box or Start Capacitor.
Boat4life

I have a feeling that this may be a common theme/root problem amongst those of us who can't start their A/C with the SPP6. I think you're on to something. But...I don't quite understand how you are isolating the SPP6 nor how this would work.

[stvhelm]

Im new here just found this thread after buying a spp6 cap to hook up to my cruisair sx16 16000. Do you have any pics of where to conmect it to this unit? I opened it up looking to find a small run cap but i dont see it.
I also have 2 honda 2000s that i pair together and works fine to run the ac.. actually 2 honda 2000s paired can run 2 boats ac's together. I have done it many times. Just boat with a buddy who also has a eu2000 and pair em up and you both run ac.

[Obi Wan]

I'll try to remember to take a picture the next time I'm at the boat.

[Obi Wan]

Here is the electric panel for my Cruisair. The start capacitor is at the top - the SPP6 is off screen, wired in parallel with the start capacitor.

[Obi Wan]

Of course, Cruisair does sell a "SmartStart" device to "Reduce Startup Surge." The only problem is they sell it for the outrageous price of $530. It's part #337975 for the 115v one. I would love to hear if anyone has ever bought/used one of these. It is cheaper than a second Honda generator (a new one anyway)...