Harmonic whine with Accentra 52i distro fan

[Peterfield]

I wonder if any other Accentra 52i insert owners have experienced this. I noticed ever since I fired up the stove there has been a harmonic whiny sound (don't know what else to call it) when the distribution fan kicks on. I have had the fan on low or medium and it's been a constant sound whether the stove is in manual or temp mode and whether it is maintaining heat or warming up the house after shutdown for cleaning. Last night it was colder than other nights so I increased the fan to high and the noise surprisingly disappeared and all I could hear then was the wonderful whoosh sound of heated air exiting the stove. I immediately started playing with the fan speed control and discovered from medium high to high speed, the fan doesn't make this noise but as soon as I slow the fan to a low to medium speed, the noise returns. Logically, ash as nothing to do with the sound because this has been going on since installation. I have only had the stove on since Nov. 1 so no wear and tear issues to worry about. I am planning on contacting the dealer but before I do that, I thought I would solicit any advice from fellow Accentra 52i owners. I did see a post from an Englander owner with a similar issue and the company replaced the motor in question and the noise stopped.

 

[JDenyer236]

When you vary the speed of electric motors, especially shaded pole motors, by varying the voltage which is what these stoves do, you often times get an electrical whine at the lower speeds. Variable frequency driven motors do not exhibit this type of behavior, but they are really, really expensive and require an expensive inverter to drive them. Just my thoughts.

 

[Husky]

I have a new Accentra 52i insert, installed this summer, and do not here this sound at any speed. I would call dealer and have motors replaced. On low I can hardly here my stove running.

 

[F4jock]

I have a new Accentra 52i insert, installed this summer, and do not here this sound at any speed. I would call dealer and have motors replaced. On low I can hardly here my stove running.

No such problem here either.

 

[JDenyer236]

No whine here either, but I do know the noise that the OP is talking about. A replacement motor may very well fix the issue.

 

[Peterfield]

One added note, my wife has better hearing than me (reminds me all the time) and she is hearing the whine at any fan speed.

 

[Dhosh]

If your wife hears the wine better than you do, then she should switch to a better wine!

 

[Big papa]

One added note, my wife has better hearing than me (reminds me all the time) and she is hearing the whine at any fan speed.

Give it a chance to break in if it gets worse call the dealer no worries mate it's under warranty!

 

[Peterfield]

Tonight I fooled with the speeds and thought I got a little more range where it didn't whine. Hoping that trend continues. I am amazed how the stove keeps the temperature of the room within a degree of where the temp is set. The FSU's I'm burning are ashy but the stove chews through them. Can't wait to see the performance with a higher grade pellet.

 

[SidecarFlip]

When you vary the speed of electric motors, especially shaded pole motors, by varying the voltage which is what these stoves do, you often times get an electrical whine at the lower speeds. Variable frequency driven motors do not exhibit this type of behavior, but they are really, really expensive and require an expensive inverter to drive them. Just my thoughts.

Your thoughts are correct and that applies across any and all manufacturers. Ifany manufacturer went to a freq controlled motor setup, it would one, be prohibitively expensive and two be much larger physically because even solid atate frequency drives take up lots more room.

The best alternative to reducing the ingerent harmonic hum/whine is to make sure the motor mounts are resilient and run the motor in the higher 2/3rds speed ranges. Any shaded pole motor will exhibit harmonic whine at lower rpm when the input voltage is electronically chopped but the cps remains constant. Fact of physics.

 

[ZBrooks]

Get it replaced. My distribution motor was bad out of the box when I installed my stove earlier this year. New motor, no more harmonics. It drove me nuts!

Another member solved this same issue with a new motor, as well, on his Harman last year.

 

[SidecarFlip]

Never fear, your new motor at some point will develop harmonics too. As mounts loose their resilency and bearings wear, the inherent harmonics of a shaded pole motor will return.

 

[Peterfield]

I hear what folks are saying about the type of motor but if I don't hear it on the display model but I do hear it on mine, anecdotally either something is amiss with one of the motors or the installation. Thanks for all the info and I love this forum. I will drop by the dealer and have him fire up a 52i and double check and then discuss options with him.

 

[SidecarFlip]

If it's warrantable, all well and good in as much as drives aren't that inexpensive (about a hundred bucks or so). Probably costs a buck to make but that is supply chain economics again....

Sounds like you just got it, might as well 'go for the gusto'....

When she's out of warranty, some minor disassembly of the drive and a new set of synthetic rubber biscuits will do it. Faucet washers make excellent vibration dampeners.

 

[ZBrooks]

The motor is a warranty item. If I were you, I would just call your dealer, tell him the issue, and that you would like a new one. It is a simple process for them to make the swap.

 

[Peterfield]

The motor is a warranty item. If I were you, I would just call your dealer, tell him the issue, and that you would like a new one. It is a simple process for them to make the swap.

Well, the Harman tech visited today and swapped out both distro motors. No more whine. There certainly is some noise associated with the operation of the blowers but now at least it doesn't sound like fingernails dragged across a blackboard. Now I can hear my wife again.... wait a minute........

 

[JDenyer236]

Well, the Harman tech visited today and swapped out both distro motors. No more whine. There certainly is some noise associated with the operation of the blowers but now at least it doesn't sound like fingernails dragged across a blackboard. Now I can hear my wife again.... wait a minute........

Great to hear you got it sorted out, now go enjoy your stove