Symmetra PX 80kw showing zero input frequency

[Anonymous user]

Hello,

I am hoping someone might have seen this issue / has an idea where to start looking for a fix.  I have a APC Symmetra PX 80KW that I am setting up and everything seems fine but when turning on the ups I  get "AC adequate for UPS but not for bypass"  the ups starts and seems fine,  runs on bats, etc.   I did scan through the menu and see why its giving that message,  it shows "Input Frequency 0 hz .   

Has anyone had this problem before?   where does the UPS read the frequency from?   The 480v to 208/120 MBP shows the correct 60hz

Thanks for any help. 

[voidstar_apc]

I'm not very familiar with the UPS -- I've worked mostly with the modular distribution panel. The message indicates while the UPS can run on the incoming AC, it's not acceptable to feed directly to the load (ie, bypass). If the input frequency shows 0Hz, maybe the phase rotation is wrong? You can call APC to get in contact with support specialists who are familiar with the Symmetra PX 80kVA.

[Anonymous user]

Thank you for the reply,  I checked the phase rotation today and it is good,  Clockwise.  

[Anonymous user · Accepted solution]

Problem solved,  just in case someone searches for it again. 

I scanned over another PX80 that we have,  it seems this unit must have had a external bypass setup,  it was missing the bus bars between Mains input and bypass.   once installed the unit was fine.