Laboratory Refrigerator Premature Failure - LabRepCo L2X-10-HG

[fmashockie]

I work as an in-house engineer for a biotech company.  I maintain their lab equipment.  We have a lot of lab refrigerators.  And I've never seen a fridge fail in this manner.  Over the weekend, I get an alert from our temp monitoring system that one of our fridges was reading a temp >7C (they are set at 4C).  The temp data did not appear to indicate this was a door opening, but it seemed like an equipment malfunction because the temperature was slowly increasing.  When I got in, the fridge was reading ~13C.  The compressor was on and very hot.  But neither the evaporator fan nor the condenser fan was on.  I thought that was strange.  I took a closer look at the condenser fan and saw that it was getting power (AC 120V), but the impeller was not turning - it was caught in the fan's frame.  I then looked at the evaporator fan - it too was getting power (same model fan).  I removed it from circuit and tried to power it with my variac - it was completely shot.

It looks like the evaporator fan died first, and then when the fridge couldn't reach the setpoint, the condenser fan and compressor continued to stay on for a long period of time (relatively... couldn't have been more than a few hours because the temp data captures the compressor duty cycle which is ~30 min).  The condenser fan wore itself out - the impeller shaft grinded itself down to the point that it popped out of the retaining ring and came out of the stator and got caught in the frame. 

I've never seen a fridge fail in this manner.  And it is less than a year old, still under warranty (just barely).  But I don't even want the original fans.  They seem to be of real poor quality (I will add the make/model tomorrow). 

Just thought I would share this here.  Stay clear of this fridge make/model if you work in lab!  They aren't cheap either!! (link to the website where fridge can be bought https://www.labrepco.com/product/futura-plus-series-10-cu-ft-compact-laboratory-refrigerator-hinged-glass-door-2/)

[fmashockie]

Fan make/model is the following:

Mutual Motor
Model M115BA1H

100-130VAC, 0.27A 25W

Never heard of them before, but I believe these fans and their poor quality were the reason for the failure.

[thm_w]

The spec says its supposed to be a ball bearing fan, which should be somewhat reliable unless they overheat.
The size should be generic, so you could swap in a higher quality branded fan.

Either way yeah, not great result on a $3k fridge.

[jpanhalt]

That seems to be a legitimate company in Pennsylvania (attachment).  The name caught my eye as its pronunciation is similar to Revco, which was a standard in laboratory freezers years ago.  In fact, "Revco" was so common, it was used almost generically to mean a low-temperature freezer, just as Xerox was used for dry copiers.

Any company can made duds.  I would invoke the warranty, which probably has an exclusion for consequential damages.  In my experience, consequential damages can easily exceed 10X the cost of the new freezer.

[fmashockie]

Already replaced the fans with some Sunon models from Mouser and the fridge is back up and running. 

Yes LabRepCo is a very well known company and distributor of lab equipment.  My company uses them all the time.  Usually we don't have any problems.  But this was unacceptable.  I've never seen a fridge fail like this.  We have PHCBI fridges/freezers (formerly Sanyo/Panasonic) that are pushing 20 years old with their original evaporator and condenser fans.  They are still going strong.

[NiHaoMike]

Tear down the bad fans/bearings to determine exact cause of failure?

[fmashockie]

Tear down the bad fans/bearings to determine exact cause of failure?

I only did a brief teardown of the condenser fan to see how the impeller came off.  The impeller shaft had somehow grinded itself down and popped out of the retaining ring.  There was debris inside from the grinded-away part of the shaft.

But other than that, I didn't investigate the fans any further.  And I already threw them away  But that would have been a good idea!

[amyk]

Relevant video:



The best condenser fan motors are called "unit bearing" type. They'll last for decades.

[fmashockie]

Really enjoyed that video! Yes the unit bearing motors are well made.  The majority of our fridges/freezers have unit bearing fan motors for the condensers.  Some of them are pushing 20 years old with their original fan motors.  But this particular fridge is only a 10cu ft one.  Very limited space underneath for a unit bearing fan motor.  So they used 120 x 120 x 38mm axial fan.  I had to replace it with one of same dimensions.  We shall see how long these new ones last!