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

[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