AC Compressor Stopped

[Photolomy]

When we turn on the forward salon AC, everything works normal (pump, fan) but the compressor is not turning on. After troubleshooting, I don't even think it is getting power (no humm, nothing). After researching the site, this would indicate a bad TRIAC, but where exactly is it?

It is AC unit #2 in the following picture...

IMG_2218.jpg

Also, for future reference, where is the starting cap?

[Pascal]

I don’t have any on my chiller system but I thought triacs were used to activate the sea water pump.

It sounds like the control isn’t send the signal to the compressor. Either an issue with the Tstat in the room or a problem with the control board in the box on the left of your unit which should also include the start cap

What kind of controls do you have? Most modern controls have a “compressor on” indicator. Does it come on ?

[Photolomy]

I still have the original 3 knob rotary controls. Are you saying that the fault might be there?

[Pascal]

I still have the original 3 knob rotary controls. Are you saying that the fault might be there?

Yes. If the control doesn’t send the run command the compressor will not start.

[SeaEric]

IIRC the compressor won't run if it's low on freon.

[Photolomy]

IIRC the compressor won't run if it's low on freon.

It won't even try? It seemed to cool fine before.

[Pascal]

No the low pressure switch will stop It from even starting.

[Captain Ralph]

I still have the original 3 knob rotary controls. Are you saying that the fault might be there?

I have found behind the old 3 knob control, a few times, a burnt wire crimp.
If you back the panel off of the bulkhead just a couple of inches, with breaker off, you can see the slip on crimps.
Also, these wires may go to a terminal strip within 3 feet of wire with a plastic cover, found a bad crimp under there also.

[Captain Ralph]

No the low pressure switch will stop It from even starting.

Rite on. Must have pressure to turn on.

A volt meter either at the compressor or on the capacitor will prove ACv at the condensing station.
Pretty sure there is no Triac on your 3 knob control system.

[JuiceClark]

<I share this only for chuckles - there's no lessen here!>

Whatever that controlling solenoid is, which turns on the water pump when any of the units is switched on, was bad on my a/c system. So, the previous owner actually ran a new wire directly from the water pump to the breaker panel. (one of those solid yellow wires you use in the house) So, you had to go into the ER and throw the raw water pump breaker before turning on an a/c system.

I had to completely replace the 8kw system in the master because the compressor was somehow completely shorted out.

No biggy - it was only $7,000 to replace the blown system, undo the silly business and get all four units running properly. I've spent about that same amount renovating the entire rest of the boat so far.

Actually, there probably is a lesson in there...or I'm just pandering for sympathy.