Required Output Current Protection?

[BillP]

Hi~~

We plan to use Galaxy 5500 to replace order ups. We have some issues about 5500. What' is "Required Output Current Protection"?

Thanks for your help.

[BillP]

overcurrent refers to the circuit breaker size. i don't know much about 3 phase power (i deal mainly with single phase) but it seems like the UPS output (like if you wire the output to a panel), each output needs to have a 40A breaker..?

[BillP]

Thanks, Angela.

For balancing 3 phase power (each phase), does APC suggest putting 40A breaker on UPS output (each single phase)?

[BillP]

as I am based in NAM, I asked someone EMEA for some advice. We don't require this output breaker protection in NAM.

we have checked all the Galaxy 5500 models that that we could find on the web page, it seems that all of them have this value listed at 58A besides G55TUPSM40HS - is that the one you were looking at? the installation manual for the above model states that a 58A protection is needed (there is no mention about 40A) so maybe that is incorrect anyway.

in conclusion, no matter what the correct A value is (40A or 58A), that value should be the value of the breaker/fuse per phase on the output. according to our calculations, the value should actually be 58A, so maybe the information displayed on the web page for that model is incorrect and we'll get it updated, if so.

Hope that answers your question.

[BillP]

Thanks for your response.

I have checked the installation manual for G55TUPSM40HS, too. There is no mention about 40A.

It really bother me that "Required Output Current Protection" and "Output Current" are different. Actually, G55TUPSM40HS is not only one (40A v.s. 58A),  e.g. G55TUPSM120HS (80A v.s. 174A), G55TUPSM80HS (63A v.s. 116A) and other models.

[BillP]

I got some additional information for you today.

This is for the output individual circuit protection .These protection systems ensure discrimination on all of the output circuits connected to the unit. If the recommended downstream protection is not installed, the result may be breaks in the supply of power longer than 20 milliseconds on all the other output circuits.

For the main breaker,

Regarding Neutral output current : refer below

Hope this makes sense because I don't understand it well myself

[BillP]

40A is recommended upstream protection for 40kv ups. So, maximum value is 40A on each phase, is it?

Thank you.

[BillP · Accepted solution]

Yes, 40A for each phase on the output.