ABB ACH550 HVAC speed drive wouldn't turn back on.

[ddcbacnet]

Faulty under-voltage relay? Is it possible to readjust at what voltage it drops out?

[ddcbacnet]

Well actually I didn't see it inside the drive. And voltage seems to be within the range (567-570V on 575V system)

[NoahsArcFlash]

Faulty under-voltage relay? Is it possible to readjust at what voltage it drops out?

In my case, the set-point (not even sure if it was adjustable, might have been) wasn't an issue. if i remember correctly, the relay was a NO contact in the control circuit portion of the drive. The coil went bad and it kept the drive off. I switched the connection to the NC terminal and presto it came to life (temp. fix of course)

[Mike Doran]

do you have o/m manuals? has pretty good troubleshooting chart at back of book or can call abb 800-help-365

[ddcbacnet]

Spoke to building engineer today. Speed drives are dead as a doornail and not subject to repair. It was caused by internal electronic failure within one of the components. Same component in all three drives. They did not mention which one.

They say they will never turn them off ever again

Lesson to learn: ALWAYS commission devices and systems you are about to upgrade.

[Jbart]

I have seen where someone accidentally hits a low voltage wire on a high voltage something (24volt wire hits a 277 volt leg) and instantly everything on that 24 volt circuit (safety or control) will never work again. Sometimes it is visible with small black arcing sports and sometimes not.

[Thaaguy]

I don't think that in my case the displays stayed off...just that the drives would not run...but I could be misremembering. If you have Eclipse bypasses you have to have the proper profile on the drive or nothing will work....on a new drive there is a paper attached to the thing - on old ones, who knows... Anyway, just a thought, and since the ABB man said it was electronic failure it probably isn't even relevant!

[ddcbacnet]

I found energized shield on one of FLNs. It measures 14VDC to ground(O.o WTF?).
New VFDs detect insufficient grounding/network disturbances.

I am trying to find out if poorly wired FLN could cause me all that head-ache.

[Jbart]

I found energized shield on one of FLNs. It measures 14VDC to ground(O.o WTF?).
New VFDs detect insufficient grounding/network disturbances.

I am trying to find out if poorly wired FLN could cause me all that head-ache.

If you are controlling through comm it sure can. Otherwise no.

[Mike Doran]

have worked with a number of these and have never had that happen to me until i read this post, then the other day while starting up a unit, i shut the unit down,turned around and display was dead,have multiple fans so i took keypad from another and it was blank on this drive too, went and got a patch cable (just for kicks) and display lit up, anyway found coupler between drive and keypad had junk in it shorting it, was able to clear out and all is good again.

[Jbart]

have worked with a number of these and have never had that happen to me until i read this post, then the other day while starting up a unit, i shut the unit down,turned around and display was dead,have multiple fans so i took keypad from another and it was blank on this drive too, went and got a patch cable (just for kicks) and display lit up, anyway found coupler between drive and keypad had junk in it shorting it, was able to clear out and all is good again.

Good job! Good to know

[RLF2986]

well im sort of having the same issue, i am a building engineer and upon arrival at work today my ACH550 drive was completely off (no power no nothing). i have reached out to our outside contractor but have yet to get a call back. Is there something i can check to see if i can resolve the issue?

[Mike Doran]

you need to make sure you have power to the drive first, not a lot of " user serviceable " stuff inside, will need ABB guy to look into it