208/120 volt supply vs 240/120 volt supply

[NWIGenerator_apc]

This was originally posted on APC forums on 12/27/2015

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I have an older APC UPS model number SYAF16KRMT currently connected to a 208 volt feeder.  I would like to know if the current connection without modification could be powered in an emergency situation with a 240 volt power feed.  Any assistance is greatly appreciated.

[NWIGenerator_apc]

This was originally posted on APC forums on 12/27/2015

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The rating of the equipment is 120/208, 120/240

[mitsmith_apc]

This was originally posted on APC forums on 12/28/2015

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Hi Chris,

The symmetra Lx can take 208 or 240. When you get the 240volts in the unit will still output whatever you have it set at (I am guessing 208volts). The issue is when you have 240V in and 208V out you will likely get a bypass out of range error message. If the unit has a reason to go to bypass (overload or other internal fault) it will not transfer and will just drop your load. It is designed to do this to protect your load from a sudden jump in voltage (208 to 240). 

As a standard we always recommend outputting the same voltage that you are inputting (208 in 208 out or 240 in 240 out) to prevent any abnormal behavior with the unit.  

[NWIGenerator_apc]

This was originally posted on APC forums on 12/28/2015

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Thank you Mike.  That is exactly as we thought.  To be sure, in this case, this will only occur when the automatic standby generator is in use to power the UPS (extremely rarely).  I feel safe that we will not cause harm to the UPS.   

[mitsmith_apc · Accepted solution]

This was originally posted on APC forums on 12/29/2015

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Hi Chris,

Yes it will only be when the generator is supplying the power that you will experience issues.