Buffering equipment

This table shows the effectiveness of certain types of equipment at mitigating various disturbances.

In the chart, a 'Yes' indicates that a particular piece of equipment will help mitigate a certain type of disturbance. A 'No' means that the indicated piece of equipment will not help mitigate a particular disturbance.

Please refer to our terms and definitions page for an explanation of each type of power quality disturbance.

Type of Equipment Type of Disturbance
Transient Sag Swell Interruption Distortion (Harmonics) Flicker Noise Frequency Deviation
Surge Suppressor Yes No No No No No No (1) No
Filter No No No No Yes (2) No Yes No
Isolation Transformer Yes No No No No (3) No Yes No
Voltage Regulator No Yes Yes No No No No No
Power Conditioner Yes Yes Yes No (4) No (5) No Yes No
Uninterruptible Power Supplies Yes Yes Yes Yes Yes Yes Yes Yes
Standby Power Supplies No No No Yes (6) No No No No
Table notes:
(1) Some surge suppressors incorporate filters to reduce noise.
(2) Filter must be properly designed to be effective against harmonic distortion.
(3) Well-designed isolation transformers can reduce some harmonic distortion.
(4) Motor-Generator sets provide limited protection against momentary interruptions.
(5) Motor-Generator sets can protect against harmonic distortion.
(6) Standby Power Supply units may not protect against momentary interruptions.