SUA3000XRT output amp confusion

[BillP]

This question was originally posted by Glenn on APC forums on 3/10/2009

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IHAC who's building electrician is advising them against a SUA3000XRT UPS that they just received. The input is a NEMA 6L-20P. Two of the four outputs are NEMA 6L-30R. He states that you can't use 30 amp outputs when you only have a 20 amp input. It makes sense to me but I'm not completely savvy to the internals of a UPS and whether they can provide these tow 30 amp circuits or not. It seems odd that there would be this configuration if it wasn't sound. Any help in explaining this will be greatly appreciated.

[BillP · Accepted solution]

This reply was originally posted by Oscar on APC forums on 3/11/2009

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The L6-30 receptacles are still rated for 20 amps. The amperage on the output is limited to the input plug type. These units were made with L6-30 receptacles so that you can connect our stepdown transformers to provide 120V. Our generic stepdown transformers has an L6-30P for the input, being that this is a 208 V UPS, having L6-30 receptacles makes this compatible configuration ideal.