Eaton Cutler-Hammer FP-5000 Instructions Manual page 86

Page 5-38
5.5.2.8 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 Displace-
ment 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-5000 will trip on.
Reset PF: This setting is the apparent power factor at which
the FP-5000 will reset the apparent power factor
function. It is like setting a hysterisis for the
Trigger setting.
Delay: This setting defines the delay (in seconds) that the
Trigger PF must be active before the FP-5000 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.
watt
PF
=
VA
apparent
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
=
(watt
displacement
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.
5.5.2.9 Zone Interlocking
Zone Interlocking
The zone interlocking setting consists of settings to configure a
Zone In and a Zone Out setting. Both Zone In and Zone Out
settings can be set to Disable, Phase, Ground, or Both.
Disable – disables the zone function
Phase – defining the zone function to be a phase signal
Ground – defining the zone function to be a phase signal
Both – defining the zone function to be a phase or ground signal
See Section 8.5 for more information on zone interlocking.
watt
+ var )
2 2
5.5.2.10 Alarms
Protection Alarm Settings
A full set of protection alarm settings complement the protection
elements for overcurrent, over/under voltage, unbalance and over/
under frequency. They are designated as another protection
element, for example 50P-3, and are programmed to the alarm
output relay and alarm LED indication. The settings are similar to
the protection settings described above. These elements may be
used for alarm, tripping or logic functions. Custom programming
of the output relay is required if the desired use is not as an
alarm function.
5.5.3 System Alarm Settings
This setting menu contains the settings needed to configure all of
the FP-5000 system alarm functions. Each alarm function can be
disabled. The system alarms are programmed to the alarm output
relay and alarm LED indication. These elements may be used for
alarm, tripping or logic functions. The outputs will need to be
configured if the desired use is not an alarm function. SYSALM
pickup in the Event Log Enable settings must be set to "Yes" to
enable logging of Pickup/ Dropout events related to system alarms.
Watt Power Alarm
Units: Sets the units for watts measurement
(kW or MW).
Threshold: Sets the watts threshold level in units
specified, at or above which the power pickup
event occurs. After pickup, if the watts fall
below the specified threshold, a power
dropout event occurs.
Delay (m): Sets the number of minutes that the watts must
remain at or above threshold, before the
specified trip output occurs.
VAR Power Alarm
Units: Sets the units for VARS measurement
(kVAR or MVAR).
Threshold: Sets the VARS threshold level in units
specified, at or above which the power pickup
event occurs. After pickup, if the VARS fall
below the specified threshold, a power
dropout event occurs.
Delay (m): Sets the number of minutes that the VARS
must remain at or above threshold, before the
specified trip output occurs.
VA Power Alarm
Units: Sets the units for VA measurement.
(kVA or MVA).
Threshold: Sets the VA threshold level in units specified,
at or above which the power pickup event
occurs. After pickup, if the VA falls below
the specified threshold, a power dropout
event occurs.
Delay (m): Sets the number of minutes that the VA must
remain at or above threshold, before the
specified trip output occurs.
IL17569
Effective June, 2001