mawyatt
New Member
All,
I have experienced a serious design flaw in our Cruise Air AC system. When the AC failed a few weeks ago I was able to trace the problem to the Control Module PC board. Basically the 120VAC hot is wired into a terminal stip that is soldered onto a PC board. A male lug connector is located next to the terminal board and soldered onto the PC board, this lug supplies the entire compressor startup and load current thru a stud mounted TRIAC for control of the compressor. The flaw is the copper on the PC board is not able to provide a low enough resistance and begins to heat up. Heat caused by "I squared R" for you electrical types, with startup current approaching 50amps rms and 25amps rms run current, with 4 milliohms resistance this can cause up to 10 watts of local heat at the connection!! Eventually heating to the point where the entire area around the terminal strip burns away (because the resistance increases as things get hotter) from the soldered connection creating an open circuit, yes I said completely burns away! This is a serious design flaw IMO.
My solution was to repair the PC board with a pair of solid wire jumpers across the burnt PC board (after cleaning), and connect the TRIAC wire directly to the terminal strip 120VAC hot with a spade lug. This causes the compressor current to bypass the PC board all together.
The model # for the controller board is: CruiseAir SXUF18/IHV-RMT-35ISO SMX Control circuit board.
Please check your Controller board and make sure you don't have the same issue. I am going to send this info to Crusie Air in hope that they will make this simple correction and prevent a boat fire.
Mike
I have experienced a serious design flaw in our Cruise Air AC system. When the AC failed a few weeks ago I was able to trace the problem to the Control Module PC board. Basically the 120VAC hot is wired into a terminal stip that is soldered onto a PC board. A male lug connector is located next to the terminal board and soldered onto the PC board, this lug supplies the entire compressor startup and load current thru a stud mounted TRIAC for control of the compressor. The flaw is the copper on the PC board is not able to provide a low enough resistance and begins to heat up. Heat caused by "I squared R" for you electrical types, with startup current approaching 50amps rms and 25amps rms run current, with 4 milliohms resistance this can cause up to 10 watts of local heat at the connection!! Eventually heating to the point where the entire area around the terminal strip burns away (because the resistance increases as things get hotter) from the soldered connection creating an open circuit, yes I said completely burns away! This is a serious design flaw IMO.
My solution was to repair the PC board with a pair of solid wire jumpers across the burnt PC board (after cleaning), and connect the TRIAC wire directly to the terminal strip 120VAC hot with a spade lug. This causes the compressor current to bypass the PC board all together.
The model # for the controller board is: CruiseAir SXUF18/IHV-RMT-35ISO SMX Control circuit board.
Please check your Controller board and make sure you don't have the same issue. I am going to send this info to Crusie Air in hope that they will make this simple correction and prevent a boat fire.
Mike
