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Configuration and use of the SURT003 and SRT5KTF Transformers


Configuration and use of the SURT003 and SRT5KTF Transformers

Product Line:

Smart-UPS RT, Smart-UPS SRT


SURT003, SRT5KTF - All Serial Numbers


Product Operation


The SURT003 and SRT5KTF Transformers are unique in that they can accept either 208v or 240v input and will output 120v, 208v, and 240v simultaneously. This makes them a great option for supporting multiple load types from one UPS. These units have some cosmetic differences, but the exact same technical specifications and features.

Looking at the back of the transformer, there is an Input Voltage switch on the left hand side behind a cover plate. Remove the cover plate, then set the switch to either 208v or 240v, depending on what you are feeding the transformer. Having the switch in the improper setting will cause the output voltages of the transformer to be off by +/- 15%.

The nominal output voltages with either a 208v or 240v input are as follows:

L6-20R (Qty2) - 208v (120v Hot, 88v Hot, Ground)

L6-30R (Qty1) - 208v (120v Hot, 88v Hot, Ground)

L14-30R (Qty1)- 240v (120v Hot, 120v Hot, Ground, Neutral)

5-20R - (Qty8) 120v (120v Hot, Ground, Neutral)


Please note that once your input is correctly configured, the output voltages are a direct ratio of the input.

Example: If the input selector is set to 208v, but the actual input voltage is 210v, you would see 210v from your 208v L6-30 output. All voltage regulation is performed by the UPS feeding the transformer.


If there is no power output from the transformer:

  • Verify that the UPS is supplying power to the transformer
  • Verify that all breakers on the transformer are ON and have not been tripped
  • Turn power to transformer OFF/ON
  • If issue does not resolve, contact APC Support
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