Cruisair air handler blowers- If one ceases to turn...

but yet the bearings seems good such that the squirrel cage will turn and start easily with a little help (pushing it lightly with pinkie), would putting in a new run capacitor likely cure the problem ?

(Unlike the condenser compressor for example, I don't think the type of fractional horsepower single phase motors on the air handler blowers have start capacitors, only run capacitors)

I was told by one tech that sometimes the blower motors, even with the slightest wear in the shaft bushings may happen to occasionally stop at a point where there is the slightest difference in the distances between armature and magnets and refuse to start up the next time.

And yet I wonder if part or not all of the problem is more "getting old" capacitor related ? Guess I'll find out in a week or so when a couple of replacement caps come in from eBay. In the meantime, curious what any of you have found regarding this issue ? In other words can these blowers turn effortlessly as new by hand, but still cease to work due to microscopic wear in the axle bushings causing a slight off center situation....or is a weak capacitor more likely ?

Worn bearing causes the spinning armature to be off center, which cause the magnetic field to pull more strongly on one side, which causes the motor to not be able to start turning as one side of the magnetic field is stronger than the other, that can happen. Replaced a furnace inducer motor that did this. Bearings were worn just barely.

Is there a start or run capacitor? Could also be the issue. I have a digital meter that reads capacitors.

sdowney717 said:

Is there a start or run capacitor? Could also be the issue. I have a digital meter that reads capacitors.

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I find that question very odd considering I specifically addressed it in my post already. In fact that was the whole point of the topic !

But I did enjoy your other info. Now wondering if a slightly higher uF run cap might overcome the bearing wear issue for awhile ? (assuming there is any bearing wear..may not be) The cap on each blower now is only 2uF rating.

FWIW, I also have a digital cap meter ("Capacitor Wizard" is the brand) but I don't think it is accurate for caps as small as 2uF.... but to be honest can't remember now...maybe it would read that low.... forgot I had the thing been so many years since I've needed it on my CNC control repairs...back at my shop.

Wiggle the shaft of the motor and see if there is play evident, should be very little. Compare play to the unit that runs.

If you don't have a meter to check capacitor, swap it out with a cap from the one that runs.

https://jet.com/product/detail/b308...zlRIG4PVX0qOS5iG0BYKVpvbqz5HAp6GcYaArZm8P8HAQ

They are cheap the run capacitors, this one is 5$. An electric motor shop or HVAC supply house may be cheaper than from Cruisair Maybe you can swap one from another fan as a test. I have some here, but then I have lots of stuff I keep or pickup for parts.

Get the highest voltage rated cap you can get as it will have more headroom for voltage spikes.

sdowney717 said:

https://jet.com/product/detail/b308...zlRIG4PVX0qOS5iG0BYKVpvbqz5HAp6GcYaArZm8P8HAQ

They are cheap the run capacitors, this one is 5$. An electric motor shop or HVAC supply house may be cheaper than from Cruisair Maybe you can swap one from another fan as a test. I have some here, but then I have lots of stuff I keep or pickup for parts.

Get the highest voltage rated cap you can get as it will have more headroom for voltage spikes.

Click to expand...

As of a few days ago, I already have a couple of new replacement caps on order via a seller on eBay....just wondering in the meantime (slow boat from China apparently) if I just wasted $10 or not

Re the suggestion to switch known good cap for test... yeah I know but all the other blowers are just too hard to get to. Sometimes I think Viking purposely decided to hide all the air handlers in such strange and tight spaces just to drive future techs crazy.

Actually the dual handler for the galley and inside helm is easy to get to but the blowers are enclosed in an insulated metal box with a gazillion screws to remove to lift off the top of the box, so forget that one, rather just wait out new replacement caps as they are so cheap and the non functioning blower is not needed much at the moment anyway.

You can't totally blame Viking. You boat may have actually been built by Gulfstar.

I'm guessing you're going to need a new blower.

Capt.Bill11 said:

You can't totally blame Viking. You boat may have actually been built by Gulfstar.

I'm guessing you're going to need a new blower.

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Viking bought Gulfstar in 1988. Mine is a 1993 CPMY. Gulfstar didn't exist in 1993.

But I know what you mean...it indeed might have been built by ex Gulfstar workers. But their job description and paychecks were Viking so officially this boat was built by Viking.

Having said that, I'm guessing you are right about needing new blower but the theory was to at least try new cap first to see if that helps. Surprising to me so far no one here seems to have actual experience doing what I am proposing to do.

I have done this (replaced caps) with home condenser fans with great success but there the situation is a little different in that the fans are always vertically mounted and not as subject to the off center issue of worn bearings that a horizontally mounted blower would be.

Greetings,
Mr. C. Long shot that may be part of the problem. The speed control probably has a trim pot. Have your tried running the adjustment screw back and forth to "clean up" the contacts?

RT Firefly said:

Greetings,
Mr. C. Long shot that may be part of the problem. The speed control probably has a trim pot. Have your tried running the adjustment screw back and forth to "clean up" the contacts?

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RT, you're living' in the past m'man... There is no adjustment screw...fan speeds are all electronic... (SMX II control)

Greetings,
Mr. C. Just a suggestion...Ah, well. Old is good. At least that's what I keep telling myself...

Same thing happened to me.....Cap did not fix it, though it may yours as at least you get rotation. I replaced the entire cage for roughly $150. An exact replacement was easy to find on Amazon, even for a 20+ year old unit. Has worked like a champ ever since and the newer motor is built much better than the old one from the same manufacturer...I'll warn you, the R&R was a PITA...

My old thread on troubleshooting and Squirelcage replacement:

http://www.trawlerforum.com/forums/s31/ac-diagnostic-help-20026.html

Heron said:

Same thing happened to me.....Cap did not fix it, though it may yours as at least you get rotation. I replaced the entire cage for roughly $150.

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I hope you mean the entire blower, not just the cage, as $150 sounds about right for the whole deal. So yours was hard to turn by hand, or even seized completely ? Mine still turns as new..hell, I could probably blow on the cage like blowing out birthday cake candles, and it would start turning and then ramp up to speed from there. It's just such a PITA to get to I need to fix it long term.

Caladan said:

I hope you mean the entire blower, not just the cage, as $150 sounds about right for the whole deal. So yours was hard to turn by hand, or even seized completely ? Mine still turns as new..hell, I could probably blow on the cage like blowing out birthday cake candles, and it would start turning and then ramp up to speed from there. It's just such a PITA to get to I need to fix it long term.

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Yup...The entire rig. Tried to find just the motor but no love. Mine spun like a top. No seizure or other mechanical issue...Just a failed motor..

Lucky for me access was a piece of cake..

Heron said:

Yup...The entire rig. Tried to find just the motor but no love. Mine spun like a top. No seizure or other mechanical issue...Just a failed motor..

Click to expand...

OK just to clarify further, by "failed motor" you mean even after you spun it by hand, it would not ramp up to speed and continue running ? The situation with mine is I can just barely touch the stuck "squirrel cage" and it will immediately take off on it's own and run great.

I had another identical blower stop rotating at the beginning of summer, did the same thing..just barely touched it and it started right up...been running fine ever since... 8 months now...with numerous on/off cycles in that time.

Caladan said:

OK just to clarify further, by "failed motor" you mean even after you spun it by hand, it would not ramp up to speed and continue running ?

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Yes...Mine was totally DOA. Tried a new Cap with no success. 20 + years on that system so $150 to get it going again VS $1500+ for a new unit was a no brainer. I don't doubt I'll have to replace it all at some point, but the new blower/Cage probably bought me a few years..

RT Firefly said:

Greetings,
.Ah, well. Old is good. At least that's what I keep telling myself...

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In a lot of cases I agree

Ted

I have had two blowers fail as you described with needing a push to get going. Both of them the cap fixed the problem.

Rogerh said:

I have had two blowers fail as you described with needing a push to get going. Both of them the cap fixed the problem.

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Ah..finally someone with the exact same problem and some real world experience with it...thanks !

RT Firefly said:

Greetings,
Mr. C. Just a suggestion...Ah, well. Old is good. At least that's what I keep telling myself...

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You're right there RT. I keep telling myself everything I own is an oldie, but a goodie. Whether that still holds good after my car goes in for a service Tuesday, I'm keeping my fingers crossed. For a start the aircon needs more gas. The aircon tech who put a new compressor in about 3 yrs ago told me the other day..."Doc, in human terms this car is 100 years old, it's bound to be a bit leaky."

Crikey, it's only a 1990 Celica GT4, so what...26 years...100's a bit steep...not as if it's a cat or dog, but still...keeping fingers crossed they find nothing else too terrible and costly...

Then there's my boat. it's about 41 yrs old, and I'm hoping today I've found and fixed an annoying leak into a corner of the saloon ceiling, that never did that until I put it on the market. The beggar's getting back at me I reckon...

Not directly related to the OP's question, but . . Some boat manufacturers, including Bertram, were in the habit of mounting these little Dayton-type fans with the axis vertical. In my experience the bearings wear out fast and the fans start to rumble because they are not designed to resist axial loads. The squirel-cage fan in Heron's picture is mounted correctly - with the fan axis horrizontal.

Caladan said:

Ah..finally someone with the exact same problem and some real world experience with it...thanks !

Click to expand...

Just realize that there are several problems that could keep your motor from running. Just because someone else replaced the capacitor and that fixed his doesn't mean that this will fix yours as well.

Rogerh said:

I have had two blowers fail as you described with needing a push to get going. Both of them the cap fixed the problem.

Click to expand...

How long ago did you do the cap replacements and can you estimate how many sucessful stop/run cycles the blowers might have gone thru since ?

Also did you use the same 2uF size cap or increase to 4uF ?

As far as stop run cycles I have no idea because it went out after we purchased the boat so I don't no how much it was ran before then. Since we live in FL and the PO lived in FL I would guess it was very many. I replaced it with the same uF which I cant tell you if it was 2uF or not. It was not the same physical cap, I just got what the local AC shop had. Had to do some minor mounting changes. Agree with Wesk your problem could be something totally different but for me it was easy and cheap to replace. My tell tail was the fan worked when it got going, and the fan did not feel any bad spots when spun by hand.

Greetings,
Mr. C. My non resident alien suggests it may be a bad centrifugal start switch and I quote...


"The OP said his unit has a "run" capacitor, replaced and still not start ... if it runs fine after being turned by hand then it is probably a bad centrifugal start switch inside the end bell of the motor.

It is closed when at rest and on powerup it supplies power to a starting winding. Once up to a certain speed it opens and the motor runs normally. That is why starting by hand works.

If it just hums when power is applied, and then accelerates after a push, listen for the noise of the switch operating, it is a whirr followed by a soft click."

Caladan said:

How long ago did you do the cap replacements and can you estimate how many sucessful stop/run cycles the blowers might have gone thru since ?

Also did you use the same 2uF size cap or increase to 4uF ?

Click to expand...

Capacitors do not wear out from use. If one fails, it is usually from heat and age.
If you replace one that failed, it's best to use the same value. This is not a case where "more is better".

Some motors have starting windings that are enabled with a centrifugal switch. I doubt this is that type. If the starting windings or switch failed, it won't start.

I have had the same problem where you have to get it rolling and it goes from there, due to the viscosity of the lubrication being too high, or old. If you can get to the bearings / bushings, replace it with graphite lube and see how that works.

Perhaps if I may......

The capacitor you replaced is a "Run" capacitor rather than a start capacitor. As long as the microfarad value is correct, and the rated capacitor voltage is above the supply voltage, physical dimensions should be only a minor concern(mounting).

I would be more concerned with the voltages being supplied from the control board. This is a typical scenario that I have seen on these systems before:

When you turn the fan on, a relay closes to provide voltage to the fan motor. The contacts in this relay after many start and stops tend to get burnt. When this happens, if you check the voltage output to the fan, the voltage appears normal. Since the contacts are burnt, the relay will not pass enough current to allow the fan to run.

This can be checked by applying voltage to the fan. If the fan runs at this point, it is the control board that is at issue. If the fan still does not run, the fan motor will have to be replaced.

If I know what model the unit is I can tell you exactly where to connect voltage to make this test.

Just my $.03

WesK said:

Capacitors do not wear out from use. If one fails, it is usually from heat and age.
If you replace one that failed, it's best to use the same value. This is not a case where "more is better".

Click to expand...

"how" they fail is irrelevant to the issue at hand...the point is they absolutely do fail...sometimes totally with obvious leakage...sometimes just get weaker but still appear as new.

I replaced a start cap on a home HVAC condenser fan a few months ago. And the unit was not all that old... 2008 vintage condenser. And it was acting exactly like this Cruisair blower... fan would sometimes just refuse to come on...but if I stuck a screwdriver in there and pushed the blades a little, it would run fine. But interestingly, still not quite up to normal RPM (although I didn't realize that at the time)

The cap looked like brand new still. Absolutely no leakage or bulge anywhere.

So I replaced the cap and it went from that situation to running like new again...fan starts instantly and runs full RPM again every time. It was a little surprising as until I replaced the cap I didn't realize the fan was previously running a bit weak even when running.

(did no oiling, btw)

Rogerh said:

As far as stop run cycles I have no idea because it went out after we purchased the boat so I don't no how much it was ran before then. Since we live in FL and the PO lived in FL I would guess it was very many. I replaced it with the same uF which I cant tell you if it was 2uF or not. It was not the same physical cap, I just got what the local AC shop had. Had to do some minor mounting changes. Agree with Wesk your problem could be something totally different but for me it was easy and cheap to replace. My tell tail was the fan worked when it got going, and the fan did not feel any bad spots when spun by hand.

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RH...you misunderstand my question. I'm not interested in the cycles before you fixed it but the cycles after you fixed it.

In other words, if replacing the cap "fixed it" just two months ago...it might not really have fixed it and you are just lucky the blower hasn't stopped in a dead zone caused by micro wear of worn motor bushings.

But if you did this 5 years ago for example and have had many many stop run cycles since then, then the cap replacement was for sure the problem cure indeed.