[Moody38CC]

I have a CruiseAir FX10 a/c unit for the forward cabin of my boat. The a/c unit works but the multi-speed fan that blows air at different speeds (can be set by thermostat in which case it operates automatically, or manually) by pressing softkey buttons on the control unit in the cabin, a SMX II control system. The problem lies not with the SMX II control system because I switched it out (it is plug and play wiring) with the larger a/c unit in the boat salon and it operated the blower speeds on that system just fine. I had a technician come to look at it. He said the blower motor was bad and wanted to order a motor and new squirrel cage fan for $600.

I took the motor home and ran some power to it and it seems to spin OK when given 110V power. It has only one set of windings, so I’m not sure how the speed is varied by its control unit. But if it spins in response to power, would it be OK? The motor is a FASCO Type UB, 115V AC, and one can get Taylor Made U63B1 replacement models for $200. Am I being taken or missing something?

 

[O_salt]

Hi, if the fan runs at home, it is not the fan that is the issue.

The SMXII display is not what controls the fan. The display controls the power logic box located on the condenser of the HVAC unit.

If the fan does not blow or does not change speed ( I couldn't tell from your email) the issue is probably the same; the triac that controls the fan has failed. The fix is to replace the SMXII power logic box.

A work around is to wire the blower to either the line voltage (fan will then run continuously when the breaker is on) or to the pump out put (the fan will then cycle with the sw pump). My choice would to have the blower run continuously.

Good luck.

 

[dacap06]

80% of problems with any electromechanical system are mechanical, especialy with solid state electronics in a rough and tumble environment. I'm wondering about broken wiring from years of flexing.

Before you order and replace anything, get your multimeter out and start measuring where the voltage reappears, working backwards. I'd measure it where it is supposed to arrive at the motor, where it departs from the power logic box, and where it goes into the power logic box. Compare those measurements to measurements at the same places in your working system.

 

[chucklesR]

I agree with my neighbor above - take out a volt meter and start finding the problem.

I bet the first test - voltage in from the two different plugs (forward cabin and salon) is the problem, and the forward cabin has low voltage due to poor connection or debris. Occam's Razor and all that- the simplest way to find a solution is usually the correct way. The only difference to working and not working is the plugs.

If it works out that is the problem, don't forget to call the expert and tell him he's not so expert after all, and not a good salesman either.