380VAC Service, 400VAC UPS

[Cjmeziere12]

Hey guys,

I had a customer mention that they wanted to increase a particular piece of equipment's UPS voltage to 400VAC, but their supply is 380VAC, 300A. So many questions...
First, why would anyone want to do this? I can't think of a need for an increased voltage on just the UPS. Anyone seen something like this?
Second, the majority of the unit's bells and whistles will be virtually unaffected, however, this will effect VFD/motor current draws, transformer outputs, and fuse/breaker trip settings (V=IR, P=IV, etc.). Assuming all of the selected equipment can handle the new voltage, are there any other practical concerns (or areas that aren't actually concerns in practice) that would need to be accounted for in this situation?

 

[petersonra]

Are there any 380 V services in the US?

I don't see that you would need to change any settings.

The VFD will still protect the motor as before and assuming the VFD input conductors were properly sized, slightly less input current won't hurt anything.

Breakers are mostly there to protect conductors so slightly less current in them won't require any changes there either

 

[ruxton.stanislaw]

I am not sure in their case, but based on my experience with these setups, it is more efficient; the switching power supplies of servers and network equipment operate more efficiently with slightly less waste heat. As for the UPS itself, perhaps they need that to get its rated capacity if they are running near limit or to help with power factor in the case of online conversion. You can fit more capacity per the same circuit breaker, conductor, PDU, etc. 254 V is ideal for a technology center, delivering around ~ 250 V after voltage drop is considered.

 

[zbang]

increase [...] UPS voltage to 400VAC, but their supply is 380VAC

That's only a 5% increase, most equipment won't know or care about the difference.

 

[tortuga]

Hey guys,

I had a customer mention that they wanted to increase a particular piece of equipment's UPS voltage to 400VAC, but their supply is 380VAC, 300A. So many questions...
First, why would anyone want to do this?

380Y220 is a old voltage for data centers, its like having 440Y254 instead of 480Y277, or 190Y110 instead of 208Y120 did you verify thats still whats incoming from the POCO?
As utilities notch up primary distribution voltages this has gone up over the years..
The modern service voltage is 416Y240 and the voltage rating for utilization equipment is 400Y230.

 

[ruxton.stanislaw]

One other wild guess without more information; maybe they are undervolting 440, or 460/480 volt rated equipment, in which case 400 might be enough to make it happy.