What Is Disturbance Power?
Interference power test is an experiment in which the interference emitted by the device's supply cable acting as an antenna is measured with an absorbing clamp. It is especially applied in home appliances and motorized devices.
Purpose of Disturbance Power
The purpose is to verify that the interference emitted through the device's cable is kept within limits; is to provide an alternative or additional method to radiated emission measurement.
Which Products Is Disturbance Power Applied To?
- Electric hand tools
- Motorized home appliances (vacuum cleaner, mixer)
- small appliances
- garden tools
In Which Sectors Is Disturbance Power Used?
Standards Related to Disturbance Power
- CISPR 14-1
- CISPR 16-1-3
- EN 55014-1
Disturbance Power Conditions
- Frequency range
- Typically 30 MHz – 300 MHz
- measurement pattern
- The maximum value is sought by sliding the absorber clamp over the cable.
- detector
- Quasi-peak
- cable length
- Minimum length and arrangement defined in the standard
Equipment for Disturbance Power
- EMI receiver
- Absorbing clamp
- Clamp slide rail
- Calibrated cables
Sample Requirements for Disturbance Power
- The sample should be operated in the most unfavorable operating mode
- The mains cable must be of standard length.
- Cable layout must be saved
- Load status must be specified on motorized devices
Duration of Disturbance Power
Typically half a working day.
Disturbance Power Procedure
- 1The sample is placed in the defined position and the cable is taken onto the rail.
- 2The sample is operated in the most unfavorable operating mode.
- 3The suction clamp is slid along the cable.
- 4The maximum value is recorded at each frequency.
- 5Results are compared against the limit lines.
Disturbance Power Acceptance Criteria
The acceptance criteria are the interference power limits given in CISPR 14-1.
Evaluation of Results
Based on the maximum value measured depending on the clamp position. Motor commutation is the typical source of interference.
Disturbance Power Report
- Standard applied
- Frequency range and detector
- Cable layout and clamp positions
- Measured maximum values and limit comparison
Accreditation
EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.
Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.
Scope and authorisationsRelated Regulations
- EMC 2014/30/EU
EMC / EMI Testleri — What Does This Testing Field Cover?
The section below describes the field that the Disturbance Power test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.
EMC testing answers a question with two sides: does the device emit an unacceptable level of electromagnetic interference into its surroundings (emission), and does it withstand the interference coming from them (immunity)? The two sides are measured with separate tests and separate set-ups, and both are required.
The field exists because of a simple physical fact: every conductor carrying current behaves like an antenna. A switched-mode power supply, a motor drive or the clock signal of a microcontroller radiates radio frequency energy even though it was never designed to. The same conductor also works in reverse: an external field induces a voltage across it. In an environment crowded with devices, this mutual effect means devices disturbing one another.
On the emission side, conducted and radiated emission are measured separately. Conducted emission is the interference the device imposes on its mains and communication cables and dominates at lower frequencies. Radiated emission is the field the device releases into the air and comes to the fore at higher frequencies. The two are measured in different set-ups, and the limits vary by product group.
On the immunity side, real-world sources of interference are simulated: electrostatic discharge (human touch), radiated radio frequency fields (a nearby transmitter), electrical fast transients (switching), surges (lightning and mains events), conducted radio frequency, power-frequency magnetic fields, voltage dips and short interruptions.
The standard to be applied depends on WHERE the product is used, and that choice determines the entire outcome. Residential and industrial environments carry different sets of limits; in vehicles the UNECE R10 regime applies rather than CE; for medical devices IEC 60601-1-2 brings additional requirements; and for products containing a radio, radio legislation comes into play and harmonised ETSI standards are used.
In immunity testing the acceptance criterion is a PERFORMANCE CRITERION class, not a binary pass/fail. A device continuing to function without interruption during the test, being temporarily affected and recovering by itself, or recovering only through user intervention are different classes. Which class is acceptable is defined in the product standard; the tolerance for a device carrying a safety function differs from that of a consumer device.
The most common shortcoming of an EMC file is that it covers only one side. A file carrying an emission report alone is not complete in terms of the EMC directive. The second common gap is a test set-up that does not represent actual use: if the device is measured on a bare bench with cables different from its real ones, the result does not carry over to the field.
Method groups in this field
Conducted emission
Interference imposed on the cable through mains and communication ports, measured via an artificial mains network (LISN).
Radiated emission
The field released into the air by the device, measured at a defined distance in an anechoic or semi-anechoic chamber.
Harmonics and flicker
The harmonic content of the current drawn from the mains and voltage fluctuation; the side that affects mains quality.
Electrostatic discharge
Contact and air discharge together with indirect discharge; the most frequently applied immunity test.
Radiated and conducted RF immunity
The device is exposed to a defined field strength and to an RF signal injected into the cable.
Mains-borne events
Electrical fast transients, surges, voltage dips and short interruptions.
Commonly confused in this field
- An emission report alone does not complete an EMC file; immunity must be demonstrated as well.
- An FCC report is not accepted in a CE file; the limits, measurement distances and set-ups are different.
- The EMC Directive does not apply to vehicles; the UNECE R10 regime does. Specifications requiring both together should be reviewed.
- The warning that a Class A device may cause interference in a residential environment is mandatory in the manual; market surveillance checks that this warning is present.
- The test set-up is part of the report. If cable type, length or routing changes, the result changes; measurement must be made in the series-production configuration.
- CISPR 22 and CISPR 13 have been withdrawn; their current counterparts are CISPR 32 and CISPR 35.
Which decisions these results support
- CE declaration under the EMC Directive
- The EMC part of radio equipment conformity
- A UNECE R10 file for a vehicle component
- Resolving field interference complaints and correcting the design
- Assessing the EMC impact of a board or wiring-harness change
Related Tests
Frequently Asked Questions About Disturbance Power
According to which standard is Disturbance Power made?
Disturbance Power is executed in scope CISPR 14-1, CISPR 16-1-3 and EN 55014-1. The limit values and acceptance criteria to be applied are defined in the product standard; The version valid for your product is confirmed in writing at the offer stage.
Which products does Disturbance Power apply to?
Mainly applied to Electric hand tools, Motorized home appliances (vacuum cleaner, mixer), small appliances and garden tools. Whether your product is included in the scope is determined by examining its technical specifications and intended use.
Under what conditions is Disturbance Power done?
The determining parameters are: Frequency range — Typically 30 MHz – 300 MHz, measurement pattern — The maximum value is sought by sliding the absorber clamp over the cable. and detector — Quasi-peak. The full terms are in the "Test Conditions" section on the page and vary depending on the product standard.
What kind of sample is needed for Disturbance Power?
The sample should be operated in the most unfavorable operating mode, The mains cable must be of standard length. and Cable layout must be saved. The number of samples is determined according to the product standard and the scope to be reported.
How long does Disturbance Power take?
Typically half a working day. This duration belongs to the experiment itself; sample preparation, queuing and reporting are also evaluated. A realistic schedule for your product is given in the offer.
What is the Disturbance Power result called "appropriate"?
The acceptance criteria are the interference power limits given in CISPR 14-1.