A/C blower no good

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BillyK

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Pic one is the look in the salon. Air in on top, cool air out on bottom. Pic two is in the closet behind the first pic. Pic three is from below. In pic three, there is coolant in and out, wiring for the blower and I assume a drain hose. The unit is a Marine air 16,000 BTU conditioner, that normally runs about 12 amps. This weekend it started to trip the breaker at over 35 amps. As I was trouble shooting, when I disconnected the blower wire, the unit did not trip the breaker. When I reconnected the blower, it tripped again, so I feel I have a bad blower motor.

The blower housing in pic two is a riveted sealed unit, front and back. I can reach in from the top and touch the blower wheel, but there is no obvious way to get at the motor.

Has anyone have experience with this problem and how do I fix this.

Thanks,

Billy K.
 
Bily, No expert, but why can't it be a bad breaker? Friend here had similiar issue with pump. Though pump was bad but re-wired to another breaker and it worked.
 
Dave, It's definitely not the breaker. I'm almost positive it's the blower.

Willie, Very funny, Marie and I are still laughing. ( B.O.A.T.) I need a whole new unit?

Billy K.
 
Check the unit's start capacitor (dual cap). I once found a wire that was melted at the terminal (from a bad factory crimp) in the control box that went from the terminal strip to the (dual) start capacitor. Most HV (high velosity) blowers on MarineAirr units have start capacitors.
Bill
 
Ok, then all I can say is if hard to do and you need a reference, I use Marine Specialists for A/C issues.
They are fairly prompt and usually reasonable in cost. No complaints with there work from me.

Robski who is on here is pretty good with A/C issues too.
Don (Double D) is the electrical guy.

Beyond that, I am no help! Sorry!
 
Billy,
If u can figure out how to get to the motor. im sure u can get a replacement locally. Im not very familiar. like was said , try and find the cap for the motor .

Rob
 
I agree, start with the cap. If it is not mounted directly to the blower, follow the wires from the motor, they will lead you to it. At least 75% of the time, the cap is the issue. It can be tested with some DVOM's. I keep spares at home for all of mine.........D........
 
Hi guys,

That's the problem. I can't get to the motor. Should I drill out the rivets or grind out a hole. I don't want a basket case, but at this point why not.

Thanks,

Billy K.
 
The start cap is usually not mounted on the motor in MarineAirr units. It should be on the main control board.
Bill
 
quote:
Originally posted by BillyK

Hi guys,

That's the problem. I can't get to the motor. Should I drill out the rivets or grind out a hole. I don't want a basket case, but at this point why not.

Thanks,

Billy K.

Click to expand...
If you have to remove the unit you will have no choice but to cut into the plenum/ ductwork? I would make a careful cut and then when it's time I would install a piece of starboard with set screw that you can remove to work on the unit in the future.
Perhaps I'm not understanding where the unit is in relation to the vents?
Bill
 
quote:
Originally posted by Billylll

The start cap is usually not mounted on the motor in MarineAirr units. It should be on the main control board.
Bill

Click to expand...


Hi Billy,

Do you mean in the control panel in the salon?

Thanks,

Billy K.
 
quote:
Originally posted by Billylll

quote:
Originally posted by BillyK

Hi guys,

That's the problem. I can't get to the motor. Should I drill out the rivets or grind out a hole. I don't want a basket case, but at this point why not.

Thanks,

Billy K.

Click to expand...
If you have to remove the unit you will have no choice but to cut into the plenum/ ductwork? I would make a careful cut and then when it's time I would install a piece of starboard with set screw that you can remove to work on the unit in the future.
Perhaps I'm not understanding where the unit is in relation to the vents?
Bill

Click to expand...


There is no duct work. If you reach your hand into the top hole in pic one you can feel the fan wheel, but it is enclosed from the motor. i believe the motor is behind the cooling unit in the lower hole. I am going to look for the capacitor. hopefully you are right and it is not on the motor. the fan blade spins with no wobble or noise.

billy K.
 
No Billy K. it is a slide out assembly mounted on the AC unit itself. I assume you have a 1 piece MarineAirr unit?
The small controls and the board they are mounted on is not what you are looking for. You want to get to the board that all the AC power, pump relay and the control assembly plugs into. It usually is held in place with 2 screws then the assembly barely slides out depending on if the unit's power wires had service loops installed or it can be pulled out because those wires are coming from the top side of the main control board.
Bill
 
I have access to the Compressor in the engine room. I'll be back at the boat this afternoon, take a look and report back.

Thanks for all the advice.

Billy K.
 
Doubt it s the breaker if you re showing 35 amp on the meter...

Turn off the compressor and put the blower on full then check the amp... They should be really low with just the blower. If you re pulling like 20 amps just with the blower, then yes the blower is suspect. I doubt it has a start capacitor but I guess it s possible.

Since you have the old style controls, does the pump have a relay or is it on at all time? How much is it pulling?

A couple of months ago we were randomly tripping the breaker on the saloon AC... It would run for hours just fine and then trip... Nt on compressor start up. Turned out to be the compressor relay, even the AC guy was surprised...

Before pulling the blower, I'd want to be sure that's what it is... Also try starting the blower on low and watch the amps as you increase the speed... Had one that would pop e breaker if started on high, but fine if started low and gradually increased.
 
Pascal,

When I remove the fan from the buss bar and started the compressor the breaker did not trip. Even with the fan on low as soon as I started the unit the amps went right up to 35. The pump does have a relay, but seems to be ok on the other two air conditioners. I'm pretty sure I have a blower problem, but will check to see if there is a capacitor.

I'm leaving work soon and will check on the things you suggested.

Thanks,

Billy K.
 
Wasn't really trying to be funny but that's what seems to work, often as not.

Sometimes a pro can find something everyone else has overlooked. Might be worth a call to the mfgr if nothing else. Generally if it CAN go wrong, they've already found out about it.

If the blower has to come out I would drill out the rivets before I started cutting any new holes. Rivets can be easily replaced.
 
My money is on the start capacitor based on the description. Now that you tell me the fan moves freely with your hand I am more convinced it's a high volume fan with a failed start capacitor. Bad start caps draw excessive current and the motor will not turn or if it does it might start to turn stop then try and run in reverse (real slow). It will repeat this process until the breaker trips.
A relay's failure mode is generally not a short or high current event. The coil generally opens and the circuit they control doesn't energize or the contacts get pitted from arching giving the same result the circuit it controls isn't completed. It's still possible you have a bad fan but I would check the fans start circuit (start capacitor).
Bill
 
The original problem happened on Friday. We left it alone until today. I checked the caps and all seemed well. I started the unit on low fan and it ran fine. As I turned up the speed it made noise and increased amps, but not overload. I slowed it down until the noise stopped and it is still running. I still think I have a motor problem.

Thanks all,

Billy K.
 
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