ENERGY STAR® Program Requirements
for Telephony
Eligibility Criteria (Version 2.1)
Below is the ENERGY STAR (Version 2.1) telephony product specification. A product must meet all of theidentified criteria if it is to be qualified as ENERGY STAR by its manufacturer.
1) Definitions: Below is a brief description of telephony products and their common operational modes asrelevant to ENERGY STAR.
A. Additional Handset: A commercially available electronic product with a handset, charging base andbattery, designed for use with Multi-Handset capable phone systems. To qualify, the charging baseof the cordless phone or its power supply must be designed to plug into a wall outlet and there mustnot be a physical connection between the portable handset and the phone jack.
B. Cordless Telephone: A commercially available electronic product with a base station and a handset
whose purpose is to convert sound into electrical impulses for transmission. Most of these devices
require an external power supply for power, are plugged into an ac power outlet for 24 hours a day,and do not have a power switch to turn them off. To qualify, the base station of the cordless phone orits power supply must be designed to plug into a wall outlet and there must not be a physicalconnection between the portable handset and the phone jack.
C. Answering Machine: A commercially available electronic product—also known as a telephoneanswering device (TAD)—whose purpose is to provide analog or digital storage of outgoing andincoming telephone messages by connecting to the telephone line between the phone and the phone
jack. Most of these devices require an external power supply for power and are plugged into an ac
power outlet for 24 hours a day. To qualify, the answering machine or its power supply must be
designed to plug into a wall outlet.
D. Combination Cordless Telephone/Answering Machine: A commercially available electronic product inwhich the cordless telephone and answering machine are combined into a single unit and whichmeets all of the following criteria: the answering machine is included in the base station of thecordless telephone; it is not possible to measure the power requirements of the two components
separately without removal of the telephone casing; and the unit is connected to the wall outlet
through a single power cable. Most of these devices require an external power supply for power, areplugged into an ac power outlet for 24 hours a day, and do not have a power switch to turn them off.
To qualify, the combination unit or its power supply must be designed to plug into a wall outlet.
E. Multi-Handset Model: This cordless phone system requires only one base and phone jack and, as thename implies, can support multiple cordless handsets. Each handset added to the system comeswith a battery and a charging base.
F. Cellular Telephone: A cellular telephone uses radio waves to connect to the cellular telephone carrier.
Cellular telephones are not eligible to carry the ENERGY STAR mark under this specification as they
are not considered cordless telephones.
G. Corded Telephone: Corded telephones provide the same services as cordless telephones except that
there is a physical connection between the handset and the jack, which limits the user’s mobility while
using the telephone. Corded telephones may or may not require an external power supply for power.
Corded telephones and combination units are not covered by this cordless telephone specificationand may not qualify as ENERGY STAR.
H. Spread Spectrum Technology (SST): There are two types of spread spectrum technology, direct
sequence (e.g., digital spread spectrum or DSS) and frequency hoppers. Both types are available insome digital telephony products to provide enhanced transmission range, extendable portable
numbers, and additional security.
ENERGY STAR Program Requirements for Telephony (Version 2.1)

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I.

Standby Mode: Lowest power consumption mode which cannot be switched off (influenced) by theuser and that may persist for an indefinite time when an appliance is connected to the main electricity
supply and used in accordance with the manufacturer’s instructions. Note: The standby mode isusually a non-operational mode when compared to the intended use of the appliance’s primaryfunction.1 For the purposes of this specification, standby mode is the condition in which the product isconnected to a power source and is inactive (i.e., the unit is not transmitting a conversation or
recharging a low battery); in TAD the product is idle. In this mode, conventional units may consume
energy to operate circuitry and to overcharge rechargeable batteries.

J.

Active Mode: The product is connected to a power source and is transmitting telephone conversation,and/or playing/recording a message, and/or supplying current to a low battery to charge it. The power
requirement in this mode is typically greater than the power requirement in Standby Mode.

K. Disconnect: The product is disconnected from all external power sources.
L. External Power Supply (EPS): A component contained in a separate physical enclosure external tothe telephony product casing and designed to convert line voltage ac input from the mains to lower dcvoltage(s) for the purpose of powering the telephony product. An external power supply must connect
to the telephony product via a removable or hard-wired male/female electrical connection, cable, cordor other wiring. For an expanded definition of an External Power Supply, please see the latest
ENERGY STAR EPS specification, which can be found at http://www.energystar.gov/powersupplies.
2) Qualifying Products: Telephony product types that are covered by this EPA specification are: analog
and digital cordless telephones, multi-handset cordless telephones, answering machines, combination
cordless telephones/answering machines, multi-handset combination cordless telephones/answeringmachines, and additional handsets using a variety of frequency ranges (e.g., 5.8 GHz, 2.4 GHz, 900
MHz, 46/49 MHz). Any cordless telephone, multi-handset cordless telephone, answering machine,
combination cordless telephone/answering machine, multi-handset combination cordlesstelephones/answering machine, or additional handset that is marketed to the consumer in this way andmeets the applicable product definition in Section 1 is eligible to earn the ENERGY STAR. Please notethat mobile/cellular and corded telephones may not qualify for ENERGY STAR at this time.
3) Energy-Efficiency Specifications for Qualifying Products: Only those products listed in Section 2 thatmeet the criteria below, may qualify as ENERGY STAR.
A. System-Level Efficiency Requirements
Table 1: Energy-Efficiency Criteria for ENERGY STAR Qualified Telephony Products
Product Category*•••••••••

1

Additional Handset
Answering Machine
Cordless Telephone
Multi-Handset Cordless Telephone
Answering Machine with SST
Cordless Telephone with SST
Multi-Handset Cordless Telephone with SST
Combination CordlessTelephone/Answering Machine
Multi-Handset Combination CordlessTelephone/Answering MachineStandby ModeRequirements≤ 1 watt≤ 2 watts≤ 2 watts≤ 2.5 watts

This definition is consistent with IEC 62301: Household Electrical Appliances – Measurement of Standby Power.

ENERGY STAR Program Requirements for Telephony (Version 2.1)

4••Product Category*Standby Mode
Requirements

Combination Cordless Telephone/Answering Machine with SST
Multi-Handset Combination CordlessTelephone/Answering Machine with SST≤ 2.5 watts*Note: Any power consumed by the external power supply must be included when metering the unit for
ENERGY STAR qualification.
B. External Power Supply Efficiency Requirements: All telephony products designed for use withexternal power supplies must use external power supplies that meet or exceed the Active efficiency
and power factor requirements (where applicable) of the Version 2.0 ENERGY STAR requirements
for single voltage external ac-dc and ac-ac power supplies. External power supplies used inconjunction with telephony products do not need to meet the No-load requirement of 0.3 or 0.5 watts,depending on type of external power supply (ac-ac or ac-dc) and nameplate output power (unlessotherwise required by federal standard). Please note: EPA is not requesting that telephonymanufacturers test and submit data on external power supplies.
A list of ENERGY STAR qualified power supplies is featured on the ENERGY STAR Web site, foryour reference. If the external power supply specification is revised over time (e.g., a Version 3.0
specification is developed), then similar modifications will be made to this Version 2.1 telephonyspecification within a reasonable time period. For more information on the external power supply
program, visit the ENERGY STAR Web site at www.energystar.gov/powersupplies.
4) Test Methodology: The following test procedure should be followed to ensure consistency in measuring
the system-level power requirements for electronics products. Outlined in Section A are the ambient test
conditions that should be respected when performing power measurements. These conditions ensure thatoutside factors do not affect the test results and that the test results can be reproduced. Sections B and C
describe the specifications for testing equipment and the test method, respectively.
A. Test Conditions:
Supply Voltage:

North America/Taiwan: 115 (± 1%) Volts AC, 60 Hz (± 1%)
Europe/Australia/New
Zealand:230 (± 1%) Volts AC, 50 Hz (± 1%)

Japan:

100 (± 1%) Volts AC, 50 Hz (± 1%)/60 Hz (± 1%)

Note: For products rated for > 1.5 kW maximum
power, the voltage range is ± 4%
Total Harmonic Distortion < 2% THD (< 5% for products which are rated for > 1.5 kW maximum
power)(THD) (Voltage):
Ambient Temperature:

23°C ± 5°C

Relative Humidity:

10 – 80%(Reference IEC 62301 Ed 1.0: Household Electrical Appliances – Measurement of Standby Power, Sections 4.2, 4.3)

Terminations: External speaker terminals terminated per 3.6.2.2 (IEC 107-1)
B. Models Capable of Operating at Multiple Voltage/Frequency Combinations: Manufacturers shall test
their products based on the market(s) in which the models will be sold and promoted as ENERGYSTAR qualified. For products that are sold as ENERGY STAR in multiple international markets andtherefore rated at multiple input voltages, the manufacturer must test at and report the required power
consumption, energy performance, or efficiency values at all relevant voltage/frequency
combinations. For example, a manufacturer that is shipping the same model to the United States andENERGY STAR Program Requirements for Telephony (Version 2.1)

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Europe must measure, meet the specification, and report test values at both 115 volts, 60 Hz and 230
volts, 50 Hz in order to qualify the model as ENERGY STAR in both markets. If a model qualifies asENERGY STAR at only one voltage/frequency combination (e.g., 115 volts, 60 Hz), then it may only
be qualified and promoted as ENERGY STAR in those regions that support the tested
voltage/frequency combination (e.g., North America and Taiwan).
C. Test Equipment: Manufacturers should measure and report the true standby power2 requirements ofthe product. Doing so necessitates the use of a true power wattmeter. Because there are many
wattmeters from which to choose, manufacturers need to exercise care in selecting an appropriate
model. The following items should be considered when procuring equipment and performing the test:
1. Ac Power Source (with sufficient output current for the test unit such that it meets the requirement
for ac line voltage, frequency stability, and THD).
2. True Power Meter (with sufficient accuracy, resolution, crest factor rating, and bandwidth).
3. Oscilloscope with Current Probe (to monitor ac line current waveform, amplitude, and frequency.
Optional but recommended).
4. True RMS Voltmeter (to verify voltage at the input of test unit. Optional if ac source output issufficiently accurate).
5. Frequency Counter (to verify frequency at the input of test unit. Optional if ac source output issufficiently accurate).
Crest Factor: Electronics equipment may draw current that is not sinusoidal.3 While virtually any
wattmeter can measure a standard current waveform, it is more difficult to select a wattmeter whenirregular current waveforms are involved.
It is critical that the wattmeter selected be capable of reading the current drawn by the productwithout causing internal peak distortion (i.e., clipping off the top of the current wave). This requires areview of the meter’s crest factor rating and the current ranges available on the meter. Better quality
meters will have higher crest factor specifications and more choices of current ranges.
To determine the crest factor rating requirement of the meter and the proper current range settings,
the peak current (amperes (A)) draw of the product under test in standby mode must first bemeasured. This can be accomplished using an oscilloscope with a current probe.
A current range on the meter must be selected that is sufficient to register the peak current.
Specifically, the full-scale value of the selected current range multiplied by the crest factor of themeter (for current) must be at least 15 percent greater than the peak current reading from theoscilloscope to compensate for any measurement error. (Note: It is difficult to measure within 5
percent using an analog oscilloscope.) For example, if a wattmeter has a crest factor of 4 and thecurrent range is set on 3 A, the meter can register current spikes of up to 12 A. If measured peakcurrent is only 6 A, the meter would be satisfactory. If, however, the current range is set too high, themeter may lose accuracy in measuring non-peak current. Therefore, some delicate balancing isnecessary. When choosing a meter, make sure that the crest factor is given for the current level thatyou desire.

2

True power is defined as (volts)x(amperes)x(power factor) and is typically reported as watts. Apparent power is defined as(volts)x(amperes) and is usually expressed in terms of VA or volt-amperes. The power factor for equipment with switching power
supplies is always less than 1.0; therefore, true power is always less than apparent power.
3

The crest factor of a current waveform is defined as the ratio of the peak current (amperes) to the rms current (amperes). The crest
factor for a sinusoidal 60 Hz current waveform is always 1.4. The crest factor for a current waveform associated with a productcontaining a switching power supply will always be greater than 1.4 (though typically no higher than 8).
ENERGY STAR Program Requirements for Telephony (Version 2.1)

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Figure 1
2.50

Current of Unit
Under Test

2.00
Current (Amps)

1.50

Sinewave Current

1.00
0.50
0.00
-80

-0.50

20120220320420520620

720

-1.00
-1.50
-2.00
-2.50
TimeFrequency Response: Another issue to consider when selecting a wattmeter is the frequency
response rating of the meter. Electronics equipment may cause harmonic waveforms that can lead toinaccuracies in the power measurements. For example, electronics equipment powered by switching
power supplies typically produces odd harmonics up to the 21st. To ensure that the harmonics areproperly addressed, ENERGY STAR recommends the use of a wattmeter with frequency response ofat least 3 kHz. This will account for harmonics up to the 50th, which is recommended by IEC 555.
Resolution: Manufacturers should choose a wattmeter that can provide resolution of 0.1 watt orbetter.
Accuracy: Catalogues and specification sheets for wattmeters typically provide information on theaccuracy of power readings that can be achieved at different range settings. If the power
measurement is very close to the energy-efficiency guideline specified in these Program
Requirements (Eligibility Criteria), a test procedure with greater accuracy will be necessary. For
example, if the ENERGY STAR specification is 1.0 watt or less and the resulting accuracy of thewattmeter at the test settings is ± 0.1 watts, then a power measurement of less than 0.9 watts will
ensure that the product qualifies for ENERGY STAR.
Calibration: To maintain their accuracy, wattmeters should be calibrated every year with a standard
that is traceable to the US National Bureau of Standards (NBS).
D. Test Method: The following are the steps to be used to measure the true power requirements ofthe product under test (PUT) in standby mode. To view the definition of true power, refer toFootnote 2 on page 6.
1. Power the PUT. When rechargeable batteries are involved, the PUT must be fully charged(allow up to 24 hours).
2. Power on all test equipment and properly adjust operation range. Connect the test equipmentand PUT.
3. Check that the PUT is connected to an external phone jack before and during testing. This isdone to ensure that the product is tested in a manner consistent with the way the consumer willuse it.
4. Check that the PUT has all settings equal to the factory default settings (i.e., unit must be in thecondition shipped to the customer).

ENERGY STAR Program Requirements for Telephony (Version 2.1)

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5. Verify that the PUT is in standby mode (not disconnect mode).
6. Either verify that the wall outlet power is within specifications or adjust the ac power source
output as described in Section A (e.g., 115 Vrms ± 3 Vrms, 60 Hz ± 3 Hz).
7. Set the power meter current range. The selected full scale value multiplied by the crest factor
rating (Ipeak/Irms) of the meter must be greater than the peak current reading from theoscilloscope.
8. After the PUT reaches operating temperature and the readings on the power meter stabilize,(times may vary depending on product) take the true power reading in watts from the power
meter.
9. Record the test conditions and test data. The measurement time shall be sufficiently long tomeasure the correct average value to within a +10% - 0% error, up to 24 hours but no less than
2 hours. If the device has different standby modes that can be manually selected, themeasurement should be taken with the device in the most power consumptive mode. If themodes are cycled through automatically, the measurement time should be long enough toobtain a true average that includes all modes.
5) Effective Date: The date that manufacturers may begin to qualify products as ENERGY STAR, underthe Version 2.1 specification, will be defined as the effective date of the agreement. The ENERGYSTAR telephony (Version 2.1) specification shall go into effect on November 1, 2008.
A. Qualifying and Labeling Products Under the Version 2.1 Specification: All products, including
models originally qualified under Version 2.0, with a date of manufacture on or after November
1, 2008 must meet the Version 2.1 requirements in order to bear the ENERGY STAR mark. The
date of manufacture is specific to each unit and is the date (e.g., month and year) on which aunit is considered to be completely assembled.
6) Future Specification Revisions: EPA reserves the right to change the specification should
technological and/or market changes affect its usefulness to consumers or industry or its impact on
the environment. In keeping with current policy, revisions to the specification will be discussed withstakeholders. In the event of a specification revision, please note that ENERGY STAR qualification isnot automatically granted for the life of a product model. To qualify as ENERGY STAR, a productmodel must meet the ENERGY STAR specification in effect on the model’s date of manufacture. The
date of manufacture is specific to each unit and is the date on which a unit is considered to becompletely assembled.

ENERGY STAR Program Requirements for Telephony (Version 2.1)8