Square D Motor Logic Plus SSOLR

[Offshoreoildude]

thread238-260801

These little buggers have a nasty habit of tripping and not showing why. I see SQ-D have an FAQ that gives a small glimpse into what's going on. I would not recommend these for new designs - particularly in remote unattended applications.

http://www.schneider-electric.us/si...country=US&lang=EN&locale=en_US&redirect=true

 

[jraef]

Lookos as though you lined to a time based FAQ site and your originasl reference has aged out of the cue.

This is a long known issue with Sq. D., they have a "work around" but you have to remember to order it with the phase loss feature disabled from the factory, it can't be field altered. They offer that version now on their Pump Panels because a lot of pumps draw very little current on startup with a closed valve, so they would trip off on Phase Loss before the water started flowing.

"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
— Kilgore Trout (via Kurt Vonnegut)
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[Offshoreoildude]

I think it's more than phase loss... it might be phase unbalance. These motors are on pumps that are reasonably loaded at start up (beam pumps). After an hour or so they will start tripping out. No all of them and not on over current. These is NO information although sometimes pushing the reset button will show UB. I think that some of the motors are out of spec and running unbalanced somehow. The power supply is not an issue - a pump can trip right next to one that never trips!

 

[jraef]

Sorry, my mistake. I read over some of the older discussions we had in here about it, they were a few years ago and fresher to when I originally discovered the problem. Here is a link to one old thread that then links to another. thread238-260801


Anyway, turns out it WAS imbalance, not phase loss, that was/is the problem. The original tech buletin I had linked to from Sq. D seemes to have disappeared (gee, I wonder why...) but the evidence of this issue lingers on in the description of their "Well-Guard" oil well pump panels. In it, they make mention of the fact that if you order the Class 10 version of the Motor Logic on the Oil Field version pump panels, it is NOT going to have phase imbalance protection. That is a toned down version of the earlier statement that actually explained why. Here is the relevant text from the data sheet:

NOTE: The Class 10 Motor Logic SSOLR (solid-state overload relay) does not protect for phase imbalance; however, it does include a rubber boot dust cover.

The "regular" Motor Logic SSOL does include Phase Imbalance protection, and they used to suggest ordering the version without it for Pump Panels. Now it appears they just do it automatically. Side note: the rubber boot thing they added looks to me to be utterly superfluous unrelated drivel, could be a red herring thrown in to confuse the reader.

"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
— Kilgore Trout (via Kurt Vonnegut)
For the best use of Eng-Tips, please click here -> faq731-376

 

[Offshoreoildude]

Does anyone know the part number for the Sq D motor logic plus SSOLR that does not include the phase imbalance protection "feature"?

 

[jraef]

http://products.schneider-electric....ail&oid=090089268047c722&cat=0b00892680442d6c

"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
— Kilgore Trout (via Kurt Vonnegut)
For the best use of Eng-Tips, please click here -> faq731-376