Instructional Literature
Page
98
Effective: May 2008
Instructions for the FP-6000 Protective Relay
For more information visit: www.eaton.com
IB02602004E
5.4.2.8 Breaker Failure
Figure 21. Breaker Failure Logic Diagram.
5.4.2.9 Power Factor
55A Apparent PF and 55D Displacement PF
These are the two Power Factor protection settings: 55A device is
the Apparent Power Factor setting and 55D device is the
Displacement Power Factor setting. There are three settings,
which are the same for the apparent and displacement power
factor function:
Trigger PF
This setting is the apparent power factor that the FP-6000 will trip
on.
Reset PF
This setting is the apparent power factor at which the FP-6000 will
reset the apparent power factor function. It is like setting a
hysteresis for the Trigger setting.
Delay
This setting defines the delay (in seconds) that the Trigger PF
must be active before the FP-6000 will initiate a trip signal.
The Apparent Power Factor is computed by dividing real power
(watts) by volt-amperes. The apparent power factor computation
includes harmonics.
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.
New values of apparent and displacement power factor are
computed every 32 cycles. The power factor function operates
when the power factor is more lagging than the Trigger PF setting
for the Power Factor Delay setting time. The function resets when
the power factor is more leading than the Reset PF setting for the
Power Factor Delay setting time.
5.4.2.10 Zone Interlocking
Zone Interlocking
The zone interlocking setting consists of settings to configure a
Zone Interlock Trip and a Zone Interlock Out setting. Both Zone
Interlock Trip and Zone Interlock Out settings can be set to
Disable, Phase, Ground, or Both. Both Zone Interlock Trip and
Zone Interlock Out can be set to Forward, Reverse or Both.
Disable
– disables the zone interlocking function
Phase
– defining the zone interlocking function to be a phase
signal
Ground
– defining the zone interlocking function to be a phase
signal
Both
– defining the zone interlocking function to be a phase or
ground signal
See Section 8.5 for more information on zone interlocking.
watt
PF
apparent
=
VA
watt
PF
displacement
= (watt
2
+ var
2
)