Cruisair A/C Tripping Breaker

[Houseboat_Livin]

Hello, I'm working on my neighbors Cruisair SMXII AC/Heat unit. The boat is plugged up at the marina. When the associated breaker on the boat is switched on the marina breaker for that switch immediately trips, but the boat breaker does NOT trip. No power on the control panel, no noise, nothing. Just immediately trips the breaker. This started occurring after rolling out the new gfci installation at the marina. No surprise there. The panel within the boat has several other breakers/devices that work fine with tripping the marina breaker. So the boat panel seems to be properly grounded.

Here's what I've done so far:

1. Switched the circuit to another breaker, same result. Breaker presumably good.

2. Disconnected the circuit power at the unit to test the wiring for shorts. Neither circuit breaker tripped. Wires all ohmed out at less than 5 ohms. Wires presumably good.

3. Disconnected the water pump from the circuit. Marina breaker tripped, boat did not. Pump presumably good.

4. Checked start and run capacitiors with meter and they both tested OK.

5. Disconnected the fan wire from the logic/power controller. Breaker still tripped.

6. Disconnected the compressor from the circuit. Breaker still tripped.

7. Found a ground going from the motor to the unit case. Disconnected it from the unit case and jumped it straight to the ground lug for the unit. Breaker still tripped.

8. Checked the main connector from the logic/power controller and noticed the fan control terminal wasn't pushed all the way into the connector. Fixed that. Breaker still tripped.

9. Disconnected the logic/power controller from the unit and the breaker DID NOT TRIP.

I am assuming that the power logic controller (smxII) is defective, but I've also read that the smxII will trip the breaker if the supply voltage is too low. Not sure how true that is. However i did check the input voltage and it's reading at 120vac.

Has anyone else seen this? Do the controllers fail in this fashion? Any experience or advice would be appreciated. Thanks!

[Houseboat_Livin]

Bump, let me know if you have any questions.

[US1Fountain]

Last winter I hauled my boat to my brothers barn to work on it over winter. I had an extension cord going from my shorepower plug, into one of his barn outlets that was protected by a GFI outlet. When I would finish for the day, I'd just unplug the cord inside the barn and leave the boat end plugged in. If I had everything turned off when I returned the next day and plugged the cord back into the barns GFI outlet, all was good. BUT, if left a regular flood light switched on when I would leave, it would always trip the barns GFI outlet every time I plugged the cord in. I could then simple reset the GFI outlet and be good to go for the rest of the day. Could even run a couple of electic heaters, a few lights and it would be fine. Was just that initial plugging in of the extension cord that would trip the outlet, as long as any item was left switched on when I left the day before. I presented this issue to the board last winter thinking my boat had a wiring issue, which I traced every wire and found nothing askew. Boat back to the slip in the spring and never an issue.

[Scott Berg]

if you're tripping an ELCI shore power breaker (30ma?) you probably have a delta between the hot and neutral (with the excess current on the ground wire or going into the water). Using a leakage meter you can monitor that. Could be the circuit board, a sensitive leakage meter like a Yokogowa is your friend. Chasing down ground faults is tedious but doable.

[US1Fountain]

http://www.cruisersforum.com/forums/...ng-197857.html

[Sailshabby]

Scott’s probably right on, but have you run the shore power cable to a different pedestal? Quick check to see if it’s the supply.

[Locquatious]

This is the troubleshooting Cruise Air suggested to me at a boat show:

On Air conditioning unit:
Check Middle knob Fan Speed, Jump two wires “red and orange?”
Check wire loom butt connectors
Check plug and replace with terminal strips.
Replace motor for fan

As I recall the butt connectors were corroded in wire nuts. When cut off and reconnected the tripping stopped.

[Cadence]

Originally Posted by Houseboat_Livin

Hello, I'm working on my neighbors Cruisair SMXII AC/Heat unit. The boat is plugged up at the marina. When the associated breaker on the boat is switched on the marina breaker for that switch immediately trips, but the boat breaker does NOT trip. No power on the control panel, no noise, nothing. Just immediately trips the breaker. This started occurring after rolling out the new gfci installation at the marina. No surprise there. The panel within the boat has several other breakers/devices that work fine with tripping the marina breaker. So the boat panel seems to be properly grounded.

Here's what I've done so far:

1. Switched the circuit to another breaker, same result. Breaker presumably good.

2. Disconnected the circuit power at the unit to test the wiring for shorts. Neither circuit breaker tripped. Wires all ohmed out at less than 5 ohms. Wires presumably good.

3. Disconnected the water pump from the circuit. Marina breaker tripped, boat did not. Pump presumably good.

4. Checked start and run capacitiors with meter and they both tested OK.

5. Disconnected the fan wire from the logic/power controller. Breaker still tripped.

6. Disconnected the compressor from the circuit. Breaker still tripped.

7. Found a ground going from the motor to the unit case. Disconnected it from the unit case and jumped it straight to the ground lug for the unit. Breaker still tripped.

8. Checked the main connector from the logic/power controller and noticed the fan control terminal wasn't pushed all the way into the connector. Fixed that. Breaker still tripped.

9. Disconnected the logic/power controller from the unit and the breaker DID NOT TRIP.

I am assuming that the power logic controller (smxII) is defective, but I've also read that the smxII will trip the breaker if the supply voltage is too low. Not sure how true that is. However i did check the input voltage and it's reading at 120vac.

Has anyone else seen this? Do the controllers fail in this fashion? Any experience or advice would be appreciated. Thanks!

I know nothing about the smxII tripping a breaker. Is the voltage reading under load. Is it feasible the new dock side unit is being tripped by the smxII because of line lose in the connecting dock cable. Just a thought.

[Squanderbucks]

I remember just reading a couple of months ago about many people experiencing similar problems with many of the new or "upgraded" marina electrical systems. Do a search on the Motor and Power Yachts magazine and see what turns up.
Essentially new electrical standards are much less forgiving of wiring issues on boats and many boats are now having similar problems when they did not before. Something to do with grounding procedures changing over the years.
Apparently they said that if that is the issue it can take a circuit by circuit diagnosis to find the fault.
Turn everything off, plug in only shore power cord and test. then turn on main breaker box with all individual circuits off and each individual power user unplugged, then one by one turn the breakers and the devices on each circuit in a row, on till breaker trips. Keep going till device or circuit is found.

[Hickers]

We have a similar problem with our 6 year old cruisair unit the only difference is tbe ac runs fine on the shore power go 30/45 minutes before tripping the shore gfi. The ac runs fine on the genset, plenty of voltage and the run capacitor has been checked. I have already paid an ac tech $240 to not find a fault , perhaps I should have asked here first!

[ebs001]

It's pretty certain you have a ground fault. You can confirm this by plugging the boat into a non GFCI outlet and turning on the breaker. A GFCI trips at less than 5 milliamps leak to ground which is never going to trip a regular breaker. Once you removed the power logic controller it didn't trip which sounds like it would be the culprit of the ground fault. Moving to another pedestal will not change a thing.

My first step would be to reinstall the logic controller and try the breaker again just to confirm that it is causing the problem. Make sure that the controller is isolated. That is only power connected to it, black white and green. If the problem persists then the controller will have to be replaced. If not connect the other wires. You'll need the schematic to know what you are connecting so that you can isolate the other components to see which one is tripping the GFCI. It could also be in the wiring harness. With such little tolerance that GFCI's have it doesn't take much to make them trip so it can be very tricky to track down a ground fault.

[Kenomac]

Not enough juice coming from short power.

[Houseboat_Livin]

Originally Posted by Scott Berg

if you're tripping an ELCI shore power breaker (30ma?) you probably have a delta between the hot and neutral (with the excess current on the ground wire or going into the water). Using a leakage meter you can monitor that. Could be the circuit board, a sensitive leakage meter like a Yokogowa is your friend. Chasing down ground faults is tedious but doable.

If I recall correctly, the neutral and copper ground are sharing on the same ground strip. Could this be the cause? Should I switch the neutral/copper to a separate ground strip? My plan was to put in some walking by disconnecting one wire at a time from the smxII and flipping the boat breaker until the marina breaker issue stops. I'll probably physically disconnect the blower fan to try that prior to the process of elimination on the SMXII. Seems so strange to me that even though I've eliminated all other case grounds that it's still tripping. Except for when I disconnect the smxII. That could mean the board is bad, but it also loops back out to the other components for control, so it's tricky. Hopefully disconnecting the fan with prove successful. Do you think that the capacitors would cause the breaker to trip immediately like that? Everything I've read said they usually at least try to start the unit up before the breaker trips.

[Houseboat_Livin]

Originally Posted by Sailshabby

Scott’s probably right on, but have you run the shore power cable to a different pedestal? Quick check to see if it’s the supply.

Cable won't reach another pedestal. Didn't really think that to be the issue since everything else works fine on the AC and DC circuit, even the fridge and water heater. The cruisair doesn't even allow the display to turn on for me to even try turning the unit on. It just immediately trips the breaker.

[Houseboat_Livin]

Originally Posted by Locquatious

This is the troubleshooting Cruise Air suggested to me at a boat show:

On Air conditioning unit:
Check Middle knob Fan Speed, Jump two wires “red and orange?”
Check wire loom butt connectors
Check plug and replace with terminal strips.
Replace motor for fan

As I recall the butt connectors were corroded in wire nuts. When cut off and reconnected the tripping stopped.

This cruisair has the soft touch display/controls. No physical knobs to test. However, the fact that they mentioned the fan a few times has me wanting to take a closer look at it. There isn't any significant corrosion whatsoever. The unit is sparkling clean for being 20+ years old.