I'm spec'ing out a UPS. It's in a nonclassified area, 480V and 50KVA. I can choose either a high resistance ground or a solid ground... What factors should I consider in making this decision?
I'm spec'ing out a UPS. It's in a nonclassified area, 480V and 50KVA. I can choose either a high resistance ground or a solid ground... What factors should I consider in making this decision?
A high resistance ground is used where you want continuity of power with an alarm on a line to ground
Solid ground system will open the OCPD on a line to ground or line to line.
Its really a design decision, but with a HRG you need a ground detector and you probably knew that.
Moderator-Washington State
Ancora Imparo
Would be highly unusual (and confusing for maintenance) to install HRG in a typ UPS installation. Especially such a small kva. Safety is key. Choose a solidly grounded system. You already have uninterruptible power as long as your DC source has capacity. Properly coordinate your breakers for higher reliability.
If you have an external bypass, you have even more considerations to make.
Moderator-Washington State
Ancora Imparo
Seems like this option is intended to be connected ahead of all downstream equipment and wiring, but such equipment and wiring can be specified to handle fault currents. Would it be easier to use a solidly grounded system and have all equipment and wiring rated for the available fault current?
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