Correct APC Unit

[Anonymous user]

Hello,
My name is Mike and I am new to this discussion forum. I am looking for help to identify just which APC unit I need to provide my customer with their minimum requirements. I have to be cost conscious here and not oversell; just provide what they need.
They need a UPS unit that can support a 30 amp service, or as they put it, "we need something with a 30 amp service". If that sounds confusing, I can try and clear it up by saying that I'm certain what they are asking is for me to provide them with a UPS unit large enough for a device that draws 30 amps. However, they also do not want to go over board on costs either. The economy has really been tough on them. They want a stand alone tower one so I I originally figured an SUA3000 would work. But, someone told me that if you take 120 and divide that into 3000, you get 25; therefore it will only provide 25 amps of service....I work for an electrical company and we have ventured into this area only out of necessity so we are learning as we go. Can anyone help me on this?
Thanks, God Bles
Mike

[BillP · Accepted solution]

I kind of understand where you're coming from with the equation, but that's more in terms of estimates. Calculating VA vs watts vs amps isn't really very exact. The SUA3000 is a 3000va UPS that provides support for 2700 watts.

The input plug is 30amp, but the standard output receptacles it ships with are 15 and 20 amps. So to get a 30 amp output, you'd need the optional backplate kit, [SUA027|http://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=SUA027]... Though I'm not sure that's necessarily something you need, from the info provided.

More importantly, there's an 80% NEMA code rule to adhere to in terms of amperage. Basically it states you shouldn't pull more than 80% of the rated amperage, which in a 30a config would be 24a. That doesn't mean it's physically impossible to do so, that's just what NEMA code dictates for safety. So in theory, if they are 100% certain they need 30a service and no less, and don't have any wattage estimates, they'd need a bigger UPS - and technically at least a 40a circuit.

Hope that helps!