ABB ACH550 Bypass

[CE-TECH]

Can someone explain to me what causes the ABB ACH550 with Bypass to Automatically go into Bypass mode?

Does the Bypass somehow know if the ACH550 VFD fails? And what sort of failures force it to switch modes?

[orion242]

I may be wrong but I think it communicates with the main VFD electronics. So it could be a list of things. I would think it needs to be programmed to do so. Plenty of cases where this behavior would be less than desirable.

There are some ABB shills on here that I'm sure will speak up if they are around.

[digo]

Can someone explain to me what causes the ABB ACH550 with Bypass to Automatically go into Bypass mode?

Does the Bypass somehow know if the ACH550 VFD fails? And what sort of failures force it to switch modes?

Fireman's override?
http://www05.abb.com/global/scot/scot239.nsf/veritydisplay/5af1c2341a05ed618525730700526636/$file/ach550_phtc02u_en_revb.pdf

[jmelvin]

All depends on how your drive in configured.

Sent from my SAMSUNG-SGH-T989 using Tapatalk 2

[CE-TECH]

Ok. Well I haven't changed any configuration parameters when it comes to alarming or faults. So is there a base setup?

[RoadRunner]

Ok. Well I haven't changed any configuration parameters when it comes to alarming or faults. So is there a base setup?

Yes there is a base setup (Macro). If this drive is on a pump or ahu, I would bet the farm that it is set for the HVAC macro. If so, unless someone has altered some of the parameters, it will auto change to bypass if a drive fault occurs. If this drive has the E-Clipse Bypass option, you should see a couple of buttons and leds on the bypass section. If it is a newer style you should see a small display on the bypass section. In either event, you should see on the bypass section if it is in auto change to bypass if fault is detected.