How to quiet down a noisy inverter fan?

[ewarnerusa]

Hello,
I have a cheap ebay PSW 300 watt inverter. But it works great for my needs. It has a cooling fan that only comes on when demand warrants it. But the fan has become really noisy, sounds like a bad bearing type of noisy. I see that the fan is still spinning when it is making this noise, but it sounds awful. Typically the sound tends to go away as the inverter warms up, but lately it seems like this takes longer and longer. I'm thinking a drop of lube on the fan axle should do the trick, but I thought I'd at least solicit some input before I opened it up to try this. Thanks.
Ed

[Gdetrailer]

landyacht318 wrote:
There are a stunning array of computer fans available in all sizes. While I'd definitely remove the fan, peel off the sticker and lube the bushing, i would also snap a pic of all the specs on the fan, and try to find its ratings, then find a ball bearing fan of similar specs.

Long time back I replaced the noisy fan in my MSW inverter, with the same exact fan, when i should have researched a bit more and got a better fan.

Some designs can move more air for less noise, and usually these designs have steeper angles on the impeller blades, more scythe like blades as opposed to a straight 45 angle. Also some fans have a smaller hub and more fan blade area allowing them to move more air for less rpm and thus noise.

google 'frozen CPU'

I doubt that the noise is coming from dry bearings, instead it comes from the HIGH SPEED of the fan..

The smaller the fan, the FASTER it must run in order to get a lot of air flow..

The BEST way is to find a NEW fan of same size but with a slower RPM motor..

What needs to be done is to take the model number of the existing fan, do a internet search for the specs.. Typically you want to get the CFM, RPM and noise rating.

Then you search for a fan that has a lower RPM/noise rating that has about the same CFM..

Personally, the OPs noise issue is one of many good reasons to avoid purchasing stuff from Ebay..

You can find plenty of inverters on Amazon and if you don't like it you can easily return it.. Sometimes it is better to pay a little more upfront than to be cheap, buy cheap then spend time and money making it LESS cheap..

[time2roll]

For pin point oiling I use a clock oiler.

Example on amazon

Actually bought it for a Grandfather clock. Has proven to have many uses. The synthetic oil does not evaporate near as fast as WD40.

[RoyB]

Ed,

I always try WD40 first with the sprayer long tube. Even spraying on the shaft side might get to the bearings maybe...

Roy Ken

[westend]

To oil the fan bearing, pull off the rating/nameplate sticker and the end of the axle will be exposed. Put a drop or two of light weight oil on the exposed shaft and rotate the fan blades so the oil travels inward. Sometimes the sticker will adhere back onto the center cap and sometimes I've had to use a dab of contact cement to stick it back on.

In my collection, I have a Samlex 600 W inverter with a fan so noisy that I'm loathe to sell it and have anybody else endure the wretched noise. I could replace the fan with a less noisy fan but the Samlex is nearly brand new.

[landyacht318]

There are a stunning array of computer fans available in all sizes. While I'd definitely remove the fan, peel off the sticker and lube the bushing, i would also snap a pic of all the specs on the fan, and try to find its ratings, then find a ball bearing fan of similar specs.

Long time back I replaced the noisy fan in my MSW inverter, with the same exact fan, when i should have researched a bit more and got a better fan.

Some designs can move more air for less noise, and usually these designs have steeper angles on the impeller blades, more scythe like blades as opposed to a straight 45 angle. Also some fans have a smaller hub and more fan blade area allowing them to move more air for less rpm and thus noise.

google 'frozen CPU'

[ewarnerusa]

Gracias, Mex. I agree about not having much to lose. And I don't even need this small one since my 1500 watt PSW one works fine. But if the small one is more efficient for what I actually use it for, it seems worth it to try and keep it alive. Unless I have to spend more than pocket change...

[MEXICOWANDERER]

For fun I'd try and fix it - what have you got to lose?

These little guys are measured in millimeters not inches.

If your fan has three wires it must bereplaced by a fan with three wires.

Cheap fans use porous bronze bushings not ball bearings. Look on the rear of your squealing fan. Note the label. It will have a power rating in milliamps and volts. Your new fan sgould have the same voltage and have almost the same milliamp number.

jameco.com

Or

allectronics.com

Are a good place to find a big variety of fans. Be sure your new fan is ball-bearing.

[ewarnerusa]

LOL, My inverter collection is already up to 4...
I was just thinking about that yesterday when I thought of the Morningstar inverter as a replacement. I gambled in the beginning and got this small PSW inverter for cheap that met my needs. But then I kept gambling when looking for a bigger PSW inverter which is why I have 4 now but only use 2. If I had just bought a nice large one in the beginning, I'd probably have saved money in the long run. Isn't that how it usually works? Funny because with my mountain bike components I learned this lesson years ago.

[JiminDenver]

My little Power bright cw150 is wonderful except even left out in the truck, I can hear it's fan running at times. I can either get a slightly larger inverter that wont need the fan under small loads or go with the Morningstar fanless 300w inverter.

In the case of your fan getting larger, small inverters are pretty inexpensive.

[azrving]

I had the same problem with a cheap model. I never hear any noise from my xantrex. I think you need to try and crack it open and replace the fan or do like some of us and start an inverter collection.

[Second_Chance]

If the fan is anything like the fans in computer equipment, there may be a rubber plug on the back of the motor housing. I have re-lubed these in two ways: 1) remove the plug and drop in the smallest amount of 3-in-1 oil possible (often with a toothpick), or 2) if the plug isn't removable, use a syringe and needle (I'm a retired Army nurse) to inject a minute amount of 3-in-1 or sewing machine oil. It's easy to over-lube these motors. The alternative is to find a replacement fan (of better quality) by matching the size, voltage, and CFM specs.

[ewarnerusa]

Yeah, I haven't fully thought the idea through or opened up the inverter. Just a brainstorm of what seems like a simple solution. If I have to invest anything to "fix" this cheap unit, I'll probably just look into replacing it instead. I hear the Morningstar ones are nice and don't use a fan at all.

[time2roll]

Replace the fan. Good luck getting a drop of oil on the bearing.

[Ivylog]

Put it somewhere you cannot hear and run an extension cord.

[2oldman]

Yeah.