EMR-5000
IM02602012E
55A and 55D - PF Protection*
Available elements:
PF-55D[1] ,PF-55D[2] ,PF-55A[1] ,PF-55A[2]
*=Please Note: Some devices, depending on the ordered device, offer 55-Measurement. Some devices, depending on
the ordered device, offer 55-Measurement and Protection.
Definition Apparent Power Factor 55A (RMS - Includes Harmonics):
The Apparent Power Factor is computed by dividing real power (watts) by volt-amperes. The apparent power factor
computation includes harmonics.
PF
apparent
=
Watt
VA
Definition Displacement Power Factor 55D (Fundamental):
The Displacement Power Factor is computed by dividing the fundamental watts by the fundamental volt-amperes as
shown below. This definition is only valid at the system fundamental operating frequency. The Displacement Power
Factor isolates the fundamental portion of the Power Factor from the effects of harmonics.
PF
displacement
=
Watt
Watt
2
var
2
These elements supervise the Power Factor within a defined area (limits).
The area is defined by four parameters:
•
The Trigger Quadrant (lead or lag);
•
The Threshold (Power Factor value);
•
The Reset Quadrant (lead or lag); and
•
The Reset Value (Power Factor value).
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