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

[MEXICOWANDERER]

There is a company that markets a spray lube called "Super Lube"

I can say nothing more than the synthetic grease inside has outlasted every other spray lube I have ever used in bushings like fan bushings.

Good for you ewarnerusa! Not needlessly clogging land fill. If it starts squeaking again in a couple years no big deal but if it squeals more frequently than that then it's fall back five and punt.

[landyacht318]

Nicely done on the lube job.

40 MM fans come in 10, 15 and 20MM widths.

If/when you fan gets noisy again, and if it will physically fit, thicker fans can move more air for less rpm and noise.

If the fans position in the inverter is vertical, when the inverter is installed, the lube will likely last a good while. I've one bushing fan I relubed 18 months ago and it has been running 24/7 since

[ewarnerusa]

The freshly lubed fan is running stealthy quiet now, we'll see if holds up.

[westend]

If you PM me your shipping address, I'll send you a fan in that size. I have a bunch of them in my parts bin.

[Gdetrailer]

ewarnerusa wrote:
OK, I've opened it up and taken a photo of the fan label. I've put a few drops of oil on the fan axle beneath the sticker. I'm now googling this model number and looking for something with comparable specs. I'm navigating the Jameco Electronic link now. this fan is about 1 9/16"/40 mm on each side and 3/4"/20 mm deep.

4020 is the size, not sure about the S, the 12 is voltage and the H is most likely the air flow..

Unfortunately that appears to be a off brand Chinese motor which is made for that inverter and no real specs are available..

You can however take a cue from the current draw of .17A.. That is about the same draw as most P4 Pentium processor heatsink fans.. I would guess at a min of 10 CFM..

I found a 1U server powersupply fan which is 40x40 15 mm deep that would most likely come close to the CFM.. I can't find actual CFM or noise specs though.. They do run very fast (5K+ RPM) and have a pretty high pitch sound..

HERE

[Gdetrailer]

MEXICOWANDERER wrote:
Shipping an inverter is going to be "free"?

I can find a dozen odds & ends to fill up the 7 bucks in shipping. Things like fuses, mini chargers, 12-volt mini batteries for remotes. allelectronics.com has an excellent gooseneck mini desk lamp for eleven bucks. Coin cell batteries - on and on...

Plus it's fun to recover stuff, especially if it's for backup use.

I'm sort of curious how a PURE sine wave inverter can compete with eleven dollars. Has the PSW price dropped?

You and myself can easily "find" little electronic "trinkets" to add to an order that make the shipping somewhat "disappear".. There are many others that may not wish or need to do so..

All Electronics has a fixed $7.00 shipping cost, that is a bargain but only if you have enough items or the cost of the part is really worth adding to the cost of the item that is being repaired..

The OP bought a cheapo E-bay inverter and I quote "I have a cheap ebay PSW 300 watt inverter." which in it's self SHOULD be raising a BUNCH of red flags..

So the maker of that inverter cheaped out on the fan.. wonder what ELSE has been cheaped out on? Perhaps it is also cheaply made in the waveform? Could be cheaply made in the drivers? Could be cheaply made in the output stage?

OP didn't mention the cost of said inverter but at the moment the fan started to make noise the OP should have RETURNED the inverter.. Since it was bought via EBay the OP has no real recourse since most EBay sellers are NOT willing to take returns..

Hence the reason that EBay used to put the words "Buyer Be Aware" on their web pages..

I fail to understand why folks default to ebay with all the crooked sellers selling cheap garbage then come here and wonder why they are annoyed by a noisy fan..

The last buy I made through ebay was 9 yrs ago and that was to buy a hard to find item that hasn't been manufactured for 50+ years.. I STILL had to make several parts by hand to make that item work again..

Place the inverter deep in a cabinet where you won't hear the fan and enjoy your "bargain" until the inverter quits..

[ewarnerusa]

OK, I've opened it up and taken a photo of the fan label. I've put a few drops of oil on the fan axle beneath the sticker. I'm now googling this model number and looking for something with comparable specs. I'm navigating the Jameco Electronic link now. this fan is about 1 9/16"/40 mm on each side and 3/4"/20 mm deep.

[MEXICOWANDERER]

Shipping an inverter is going to be "free"?

I can find a dozen odds & ends to fill up the 7 bucks in shipping. Things like fuses, mini chargers, 12-volt mini batteries for remotes. allelectronics.com has an excellent gooseneck mini desk lamp for eleven bucks. Coin cell batteries - on and on...

Plus it's fun to recover stuff, especially if it's for backup use.

I'm sort of curious how a PURE sine wave inverter can compete with eleven dollars. Has the PSW price dropped?

[Gdetrailer]

MEXICOWANDERER wrote:
This fix is taking longer discussing it than the actual changing of the fan 🙂

A cheap inverter is not.going to have even a decent quality fan, nevermind a good fan.

So a surplus joint like allelectronics four dollar fan is laughably going to be quieter move more air and last 10X longer than the original. This application is for a use as needed imverter and not for something for the living room or bedroom.

$4 fan, plus $7 shipping = MORE than what the whole inverter is worth..

I wouldn't waste time or money on that inverter.. Put in the recycle bin and then start out on the right foot with a NON EBAY inverter..

The thrill of a cheap "bargain" is often followed by buyers remorse down the road..

[MEXICOWANDERER]

This fix is taking longer discussing it than the actual changing of the fan 🙂

A cheap inverter is not.going to have even a decent quality fan, nevermind a good fan.

So a surplus joint like allelectronics four dollar fan is laughably going to be quieter move more air and last 10X longer than the original. This application is for a use as needed imverter and not for something for the living room or bedroom.

[MrWizard]

start with a can of air duster to clean the fan and inverter

then lube with some silacone spray

IF that don't fix it, replace the fan

allelectronic.. has all the brushless 5v or 12v fans you could need
just select the right size

[Gdetrailer]

ewarnerusa wrote:
Gdetrailer - the fan noise isn't happening whenever the fan runs, just when it is first turned on and typically just for the first 5 minutes or so. But this noise time has been increasing. The fan spins whether it is making the noise or not, in fact I can sort of alleviate/aggravate the noise just by tilting the inverter in my hands. After it has been running for a while, the fan grinding/humming noise stops (fan is still spinning though, normal fan noise at this point) while the same loads are being applied.

Replacing the FAN or buying a better known name brand inverter is the ONLY way to "fix" it..

Putting oil in it is only going to fix it for a short time and you risk over oiling or using to heavy of a oil..

Most are a sleeve bearing, there will be a very small plastic "clip", under that clip should also be one or several plastic "shims".. Often the cheap fans they will skimp and not put or use shims.. This is often the point of failure..

Ran into that with some industrial computers at work where the heatsink manufacturer for the processor was sent a bunch a defective fans.. Without the shims the fan motors would simply squeak or grind eventually leading to the fan not running fast enough and the system board would shut down due to processor overheating..

Affected THOUSANDS of our PCs...

[ewarnerusa]

Gdetrailer - the fan noise isn't happening whenever the fan runs, just when it is first turned on and typically just for the first 5 minutes or so. But this noise time has been increasing. The fan spins whether it is making the noise or not, in fact I can sort of alleviate/aggravate the noise just by tilting the inverter in my hands. After it has been running for a while, the fan grinding/humming noise stops (fan is still spinning though, normal fan noise at this point) while the same loads are being applied.

[2oldman]

ewarnerusa wrote:
y 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?

Yes, it is.