Cruisair smx II blowing main 30 amp breaker

[tradrockrat]

Hi all. I have 30 amp shore power. I've done nothing to change any electrical for a long while and my smx has worked fine everywhere but the French islands in the Carribean. It worked fine when we got back to Texas May 11th.

We've been gone for a few weeks and arrived to find the main 30 amp breaker tripped.

I cleaned and inspected the water intake and output, the strainers and filters, and there's plenty of water going through the system.

Sometimes the ac will run for a minute or two, but most times it trips the main 30 amp breaker immediately on startup.

I have Two breakers for the cruisair, but they don't pop - just the main panel breaker.

Any ideas? Thanks.

[SailingHarmonie]

Most likely: The marina power has a residual current breaker, and you are tripping that because of current leakage not because of an overload.

Could be the fan, could be the controller, could be the water pump, could be the compressor, or the wiring to the unit.

I'd suggest a visit from a refrigeration tech.

[tradrockrat]

Originally Posted by SailingHarmonie

Could be the fan, could be the controller, could be the water pump, could be the compressor, or the wiring to the unit.

I'd suggest a visit from a refrigeration tech.

Thanks - problem is we're here now and tomorrow is the holiday. I'm going to troubleshoot as best I can tomorrow- remove, clean, and reinstall wire connections, look into any switches or capacitors, etc.

Unlikely it's the water pump as the rare times it runs for a minute or so the water pressure is great.

The controller is notorious and we're on our second one, but I'm hoping we can figure this out tomorrow.

[GordMay]

Dometic DX Remote & Self-Contained A/C Installation and Operation manual
➥ https://www.dometic.com/assets/27/52...nual_62752.pdf

CRUISAIR ® MARINE A/C SYSTEMS Troubleshooting Guide
➥ https://www.flightsystems.com/pdf/cr...ting-guide.pdf

SMX II Control Systems (DX) OWNER/OPERATOR Manual

”... AC Line Voltage Calibration
The SMX II control assembly has a built-in voltmeter that
senses AC line voltage. The microprocessor automatically
responds to sustained low-voltage conditions by shutting
down the air conditioning system to prevent compressor
damage. At installation, the SMX II voltmeter should be
calibrated to line voltage within +/- 1%. To check or re-
calibrate AC line voltage:
• Upon entering the Programming Mode, press the Down
and Up keys simultaneously. Line voltage will be displayed
in as the last two digits of the voltage. On 115V systems,
95V appears as “95”, 100V as “00”, and 120V as “20”. On
230V systems the last two digits of 1/2 of line voltage will
be displayed, therefore, 190V will appear as “95”, 200V as
“00”, and 230V as “15”.
• To check accuracy or to calibrate, turn off all on-board AC
loads and measure the line voltage with an accurate
voltmeter.
...

➥ http://www.tropicalmarineairconditio...ets/L-2362.pdf

[ranger58sb]

Originally Posted by tradrockrat

Hi all. I have 30 amp shore power. I've done nothing to change any electrical for a long while and my smx has worked fine everywhere but the French islands in the Carribean. It worked fine when we got back to Texas May 11th.

We've been gone for a few weeks and arrived to find the main 30 amp breaker tripped.

I cleaned and inspected the water intake and output, the strainers and filters, and there's plenty of water going through the system.

Sometimes the ac will run for a minute or two, but most times it trips the main 30 amp breaker immediately on startup.

I have Two breakers for the cruisair, but they don't pop - just the main panel breaker.

Any ideas? Thanks.

We had a similar situation once with a Marine Airrrrr Vector Compact self-contained unit. Turned out the connections at the compressor needed some cleaning up. They weren't visibly corroded, but removing cleaning, reattaching worked.

-Chris

[tradrockrat]

Originally Posted by GordMay

Dometic DX Remote & Self-Contained A/C Installation and Operation manual
➥ https://www.dometic.com/assets/27/52...nual_62752.pdf

CRUISAIR ® MARINE A/C SYSTEMS Troubleshooting Guide
➥ https://www.flightsystems.com/pdf/cr...ting-guide.pdf

SMX II Control Systems (DX) OWNER/OPERATOR Manual

➥ http://www.tropicalmarineairconditio...ets/L-2362.pdf

Yeah - I have all that. None of that explains blowing the panels main 30 amp instead of the ac breakers. I also cleaned all the connections I could find this morning and it ran for 10 minutes with excellent water flow. I turned it off, buttoned up the electrial panels, and now it trips the 30amp breaker when the compressor comes on again. I removed the panels again, but no good. Won't start, blows the 30 amp breaker.