Guidance on the UPS ENERGY STAR Test Method (December 12, 2013)

Overview

The document is a letter from the DOE test-method lead for the ENERGY STAR UPS programme. EPA and DOE published the final UPS test method on 10 May; stakeholders then sent further questions, and DOE decided to add guidance. The text was last updated on 12 December 2013.

A table covers five topics. As a general rule, any setting the test method does not explicitly address stays in its as-shipped (default) configuration. UPSs that accept both three-phase and single-phase input are tested on three-phase power. If a dc-output UPS cannot run at the test voltage given in Table 2, the highest normal operating voltage it supports is used instead.

The steady-state check applies only to the stability of conversion efficiency under active loads, so it is not needed at 0% load; the UPS must nevertheless be thermally stabilised for 125% of the manufacturer-specified time before the power measurement. Measurement may run longer than 15 minutes, in which case the actual period replaces t in Equation 1 for PAVG. DOE data indicate that longer durations do not alter the average efficiency.

Key points

1. Settings not covered by the test method remain in as-shipped default configuration.
2. UPSs supporting both three-phase and single-phase input are tested on three-phase power.
3. A dc-output UPS that cannot run at the Table 2 voltage is tested at its highest normal operating voltage.
4. No steady-state check at 0% load, but stabilisation still lasts 125% of the manufacturer time.
5. Measurement longer than 15 minutes is allowed; the actual period is used for t in Equation 1.
6. DOE data show durations over 15 minutes do not change average efficiency.

Using it in design

• When ingesting vendor UPS efficiency figures, record the input configuration (three-phase) and whether the values follow ENERGY STAR or IEC 62040-3 methods.
• Treat mode settings that are not specified as factory default in the loss model.
• Label the 0% load (no-load loss) point as a value taken after thermal stabilisation only.

Who should read it

Electrical design engineers who use UPS efficiency data in catalogues or loss models, and test laboratories.

Document contents

1. General: default settings
2. Section 3.B: three-phase and single-phase input power
3. Section 3.D: dc-output voltage for test
4. Section 5.B: steady-state check at 0% load
5. Section 5.C.2: measurement period

Related standards

• IEC 62040-3
• ENERGY STAR UPS Test Method

Read the document

Publication details

Authors

Bryan Berringer

Publisher

U.S. Department of Energy / U.S. EPA (ENERGY STAR)

Year

2013

Document language

English

Source type

Government / public

Access

Open licence — downloadable

Licence

U.S. public domain — U.S. Government work; free to reuse

Licence evidence

www.copyright.gov

Citation