Cruisair Capacitors

[scottinsydney]

Air con system refurbishment continues. This week I'm learning about start and run capacitors.

The twin cabin run capacitor had bloated and was replaced. I swear the fan is now running faster and blowing twice as much air.

Next is to replace OSR capacitors and salon capacitors as both systems seem slow to start up and have lower airflow than you might expect. There is a hum from the motor running the salon fan.

QUESTION: Most of the seven aircon unit's start capacitors have a small resistor soldered across the terminals... what is the purpose of this resistor? Do I need it? Does anyone know the resistor ohm range? I guess the resistors will have to be custom soldered?

QUESTION: I can get exact matches for the run capacitors in Australia. I cannot match exactly the start capacitor micro-farad range.... do I go up or down a few micro-farads in range? What actually does a higher/lower micro-farad rating do for a motor?

[KPTIM]

As for the resistors.
The resistors are a safety thing. There purpose is to bleed off any charge that may be left on the capacitor if the power is interrupted to the device. The value is not that critical typically 500K to 750K ohm. If you buy aftermarket capacitors you will have to add them yourself. You can transfer them from the old capacitors.

[Briankinley2004]

Im not sure if Amazon ships to your location but I have ordered some of mine from them. Also the Capacitorwarehouse.com has a big selection if you can get them to ship. I find locally they all have to order them and have a 3 day wait so I just get myself online.

[scottinsydney]

Thank you.

I have ordered from ebay a dedicated capacitor meter for curiosity's sake.

All the capacitors are available in Oz for about US$20 each. I'll solder in new resistors.

The start capacitors are all the same range around 43-52 MF and the run capacitors are either 15, 20 or 35 Micro-farads.

After 35 years, I'll bet all the capacitors need replacing.

QUESTION: Where do I buy/obtain new compressor/fan start relays? Is this a special Cruisair part? Apparently this relay should/might be replaced when the capacitors are replaced.

[Briankinley2004]

I haven't had to go down that road yet but I would start by getting the part number off the relay and doing an internet search. I know the control boards are brand specific but I would think the relays would be more standard.

[Reefgeorge]

This is a subject where made in the USA is important. The current crop of offshore made crappy capacitors for high voltage applications need to be avoided. I see so many of them fail early and in many cases puke acid out all over the innards of the unit. During my last rebuilds I used USA made HD Titan run capacitors and USA made BMI/Mars start capacitors. Here are mine:

https://www.ebay.com/itm/TitanHD-PRC...ss!32907!US!-1

https://www.ebay.com/itm/43-52-MFD-u...ss!32907!US!-1

My rebuilds are almost 5 years old.

Those are bleed resistors, discharging the caps for safety as said before. Either move them over. measure their value with a meter or look up their value from the color banding.

George

[scottinsydney]

Thanks. I've purchased the capacitors for the first 3 air con units. I'm told they are an American brand. I guess we will see when they turn up. I was able to get the same MF for the start capacitors.

Does anyone know about the old Cruisair start relay in compressor box? It has screw terminals. Seems newer relays may use spade connections. I don't fancy making 30 -40 new wire connections. An ebay link or part number would be great.

[Reefgeorge]

Pls supply a photo of the existing relay.

George

[Reefgeorge]

And a part number if you can find one on the unit.

George

[scottinsydney]

My capacitor tester arrived. I pulled capacitors on three aircons. Three run capacitors were all well out of range. Two of the start capacitors were out of range and the third was marginal. Replaced all.

Motors/fans run better and heating / cooling is far more effective.

capacitor-testing.jpg