ENERGY STAR Program Requirements for Uninterruptible Power Supplies (UPSs): Test Method (Rev. Nov-2017), Version 2.0

Overview

This seven-page document is the test method for determining compliance with the ENERGY STAR UPS criteria. Scope depends on product type: UPSs that run at 115 V and 60 Hz with a NEMA 1-15P or 5-15P plug are covered by 10 CFR 430 Appendix Y, while all other UPSs follow this method. Ac-output UPSs use IEC 62040-3:2011 Ed. 2.0 (Section J.2), high-voltage dc-output data-centre UPSs (above 60 V) use IEC 62040-5-3:2016 Annex F, and dc-output UPSs or rectifiers of 60 V or less use the ATIS-0600015 standards.

The unit is tested as shipped, with exceptions: dc output ports that deliver under 90% of rated output power stay unloaded, features unrelated to keeping storage charged or delivering load (such as an LCD) are switched off, and unrelated communication cables stay disconnected. Input voltage follows the precedence in Table 1, from 600 V delta down to 100 V. Dc output follows Table 2; for example 380 V dc is tested at 418 V and 48 V dc at 53 V. Power of 2 W or more is measured with uncertainty of 0.5% or better, and below 2 W with 0.01 W.

Units with several normal modes are tested at the lowest and highest input dependency, in the highest-efficiency sub-mode of each. The reference load must be resistive, and modular UPSs are tested twice, at the vendor's minimum and maximum non-redundant (N+0) configurations. Above 100 kW, back-feeding may replace a load if output power factor stays above 0.99. The energy storage system is disconnected where possible; otherwise the battery must be fully charged.

The calculations are PAVG = ETOT / t and Eff = PAVG_OUT / PAVG_IN. The unit stabilises for 125% of the manufacturer time, and in the final 20 minutes at 100% load two efficiency values (each from at least 5 minutes of data, at least 10 minutes apart) must differ by less than 1%. Efficiency is measured for 15 minutes at each load point: 100, 75, 50, 25 and 0% for ac-output and high-voltage dc-output UPSs, and 80, 70, 60, 50, 40, 30 and 0% for low-voltage dc systems. Input power factor is reported at 100% load for each mode.

Key points

1. Ac-output UPS: IEC 62040-3:2011 Ed. 2.0; dc output above 60 V: IEC 62040-5-3:2016 Annex F; dc output 60 V or less: ATIS-0600015.
2. The boundary between high-voltage and low-voltage dc output is 60 V.
3. Products with several normal modes are tested at lowest and highest input dependency, in the highest-efficiency sub-mode of each.
4. The IEC 62040-3 reference load must be resistive; modular UPSs are tested at minimum and maximum N+0 configurations.
5. Stabilisation lasts 125% of the manufacturer time; in the final 20 minutes at 100% load, two efficiency values must differ by less than 1%.
6. Ac-output and high-voltage dc UPSs are measured at 100, 75, 50, 25 and 0% load; low-voltage dc systems at 80, 70, 60, 50, 40, 30 and 0%.
7. Energy is accumulated at 1 Hz or faster over a 15-minute period at each load point.
8. Power of 2 W or more is measured with uncertainty of 0.5% or better at 95% confidence.
9. Above 100 kW, back-feeding may replace a load if output power factor stays above 0.99.

Using it in design

• Store efficiency at 25/50/75/100% load for each normal mode (double-conversion, eco/ESS) in UPS catalogue entries, measured to IEC 62040-3.
• In the loss model, interpolate this curve at the computed UPS loading, including the effect of N+1 or 2N redundancy.
• Show a warning when only 100% load data are available, since redundant designs typically run UPSs at low load.
• Keep the 0% load (no-load loss) point as its own field; it is measured at the input only.
• Note that input power factor is reported at 100% load only and must be estimated separately at partial load.
• For modular UPSs, record that measurements were made at minimum and maximum N+0 module counts and that intermediate counts are the user's interpolation.

Who should read it

Electrical design engineers who select UPSs and model losses, product-data teams, and ENERGY STAR test laboratories.

Document contents

1. 1 Overview
2. 2 Applicability
3. 3 Test Setup (setup and instrumentation, as-shipped configuration, ac-input power, ac-output power, dc-output power, measurement accuracy, relative humidity)
4. 4.1 UPS Operating Mode Conditions
5. 4.2 ENERGY STAR Guidance for Implementation of IEC 62040-3 (reference load, modular UPSs, back-feeding, energy storage system)
6. 5 Test Procedures for All Products: required calculations
7. Steady-state check
8. Efficiency measurements
9. Input power factor measurements
10. 6 References

Related standards

• IEC 62040-3:2011
• IEC 62040-5-3:2016
• ATIS-0600015.2013
• ENERGY STAR UPS V2.0 Specification

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Publication details

Authors

U.S. Environmental Protection Agency; U.S. Department of Energy

Publisher

U.S. Environmental Protection Agency (ENERGY STAR)

Year

2017

Document number

Rev. Nov-2017

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