AB E-3 Plus keeps tripping

[fgoodsky]

I have a few Allen Bradley E3 plus overload relays that keep tripping and it is indicating a phase loss. I;ve checked the connections and replaced the cabinet in the control center for 1 of the units. but it keeps tripping. I know these are discontinued, but could they just be getting old and faulty? Any direction would be greatly appreciative.

 

[Engineerj22]

Yes, That sounds like to me that the E3 is failing. Are they devicenet?

A customer has 40 of the things in one of their MCCs and that's usually the problem the E3 plus develops.

 

[fgoodsky]

yes, they are devicenet. I replaced it with another E3 that was a spare in the mcc, and it still failed.

 

[Engineerj22]

Is the motor ok? don't rule out that the motor isn't bad, or the spare E3 isn't bad. They're old. Had a customer with a controls technique field controller, it went bad. It's replacement straight from the box was also bad. They are old.

The nice thing is you can replace the E3 with an E300, you can even set the E300 in E3 emulation mode and it'll read as an E3. I did a conversion recently replacing a dead E3.

 

[fgoodsky]

yes, the motor itself and the controls for it are only 6 months old. But the mcc its hooked up too is 15+ years old.

 

[Engineerj22]

I see, if possible, find another E3 and see what happens with that. Is the E3 still visible on devicenet? When you swap out the E3, is it everything including the communication module or are you reusing the module?

If your company forbids ebay, you're going to have to get an E300 replacement. It's easier to install than I thought. If you go that route, I did write a short document on what I did to get it running. AB's documentation wasn't clear enough for me.

 

[fgoodsky]

Is the communication module the little piece at the bottom? I never switched that out. I better switch that out also.

 

[Engineerj22]

Should be the top, it's the one with all the blinking lights and the blue reset button. It might not be separatable, I'm more use to E300s.

Pic of module.

 

[fgoodsky]

Should be the top, it's the one with all the blinking lights and the blue reset button. It might not be separatable, I'm more use to E300s.

Pic of module.

Oh, Yep I replaced the whole unit minus the little connector at the bottom. lead time on a new e300 is 8 weeks.



I went in and adjusted the Phase Loss parameters, I'm hoping that buys me some time(fingers crossed)


Can you post the document on emulating the e300? I'd like to see what I'm getting into.


Thanks so much for your help!

 

[Engineerj22]

Here's the document. It's not hard, the hardest part for me was finding the EDS files for the E3 emulation. It shows up as a rev 6 E3. Rockwell has them, it just was a pain to find.

If any part of the document is unclear let me know and I'll make edits to make it easier to understand.

 

[Frost999]

4. Configuring the E300.

Once the node address is set, the Devicenet cable plugged in, and the bucket powered on, go and visit Bob Collier, the PA engineer at No. 4 BOF.

In all seriousness though; thanks for the doc.

 

[Engineerj22]

Yeah that was an oops on my part, I thought I got all the references out! It was originally written for my colleagues so they could go out and change one out because I am contracted out elsewhere. They have 40 something of the dang things in an MCC room, connected to the plc through a 1788-cn2dn. I was a little stressed about doing the download to device.

 

[fgoodsky]

Thanks so much! I'm sure this will save me some head aches.

 

[Engineerj22]

In all seriousness though; thanks for the doc.

You should meet him some time he'll tell you all about why Rslogix 5 is better than Studio 5000.

He's a hoot!

 

[jraef]

Phase loss on an E3 (and the E300 for that matter) is based on phase currents, not voltage. If ANY ONE phase current is below 30% of the motor FLA setting, it trips. If all 3 are too low, that satisfies the condition too. So make sure that when your motor is running, it has a load on it and that the E3 is set to the motor nameplate FLA. If the load is so low that the motor current is below 30% of FLA, you may need to disable the Phase Loss protection (or reevaluate why your motor is so big...)