
Configuration – 4
4–67
Voltage and Current Total Harmonic Distortion
(THD) Trip and Lockout
The Voltage and Current THD Trip and Lockout
feature will Trip and Lockout the capacitor bank
when either Voltage or Current THD exceeds its
associated THD Trip Pickup Setting.
When Voltage or Current THD increases above its
associated THD Trip Pickup Setting for the period
defined by its THD Trip Time Delay setting, the
control will Trip the capacitor bank and Lockout
further operation. If THD is still present above the
THD Trip Pickup Setting after the trip has occurred,
the Lockout will remain in effect until THD decreases
to less than the Voltage or Current THD Lockout
Reset setting for the duration of it's THD Lockout
Reset Delay setting.
If the Voltage or Current THD levels that caused the
Trip, immediately (within 1 second) decrease to less
than the THD Lockout Reset Setting when the bank
trips, then the Lockout will remain in effect for the
duration of it's THD Lockout Reset Delay setting.
A Maximum THD Lockout/Reset Operation is
counted each time the following sequence occurs:
1.
Voltage or Current THD Measurement
is greater than it's associated THD Trip
Pickup setting for the duration of the THD
Trip Time Delay.
2.
The control Trips the capacitor bank and
a Lockout is imposed.
3.
Voltage or Current THD measurement
decreases to less than the THD Lockout
Reset Setting as soon as the Trip occurs
(within one second).
4.
The THD Lockout Reset Delay times out
and the Lockout resets.
The Maximum THD Lockout/Reset Operations
setting is used to determine how many Trip and
Lockout/Reset Operations within a time period
specified by a Maximum Time for THD Lockout/
Reset Operations setting are allowed before the
control will Lockout and require a user reset either
locally or remotely to continue operation.
The THD Lockout does not allow operation of the
capacitor bank by any means except front panel
manual switch operation. This includes Automatic
Operation, Control Mode Limits being exceeded,
Time or Temperature Override, or Remote Manual
commands being sent.
A Voltage THD Lockout and Current THD Lockout
Programmable Alarm will actuate when the control
Locks out. The alarm will clear when the Lockout
clears or if reset by a user either locally or remotely.
The Lockout Reset from CapTalk is located in the
"Programmable Alarms Setup Dialog Screen"
Figure 3-43 and from the HMI Configuration/THD
Trip Settings menu.
Both Voltage and Current share the same settings
used to determine how many Trip and Lockout/
Reset Operations are allowed before the control
will lockout and require a user reset either locally
or remotely to continue operation.
(THD) Trip and Lockout Interaction with Other
Control Features/Functions
Neutral Overcurrent No Prior Operation
Both Neutral Overcurrent No Prior Operation and
this feature will trip and lock out the control. If either
of these features trips and locks out the capacitor
bank, then the other will still alarm and will still
lockout. In this scenario, if the conditions to trip
and lockout for both features still exist and one of
the feature conditions clear, the lockout would still
remain in effect until the second feature is also
cleared.
Neutral Overcurrent Prior Operation
Neutral Overcurrent Prior operation can result in
a capacitor bank being Blocked in either Close or
Open condition. The THD Trip and Lockout feature
always results in an Open. For this reason, specific
rules will apply to their interaction depending on
whether the bank is open or closed:
• If the capacitor bank just Closed and
Neutral Current results in the bank
retrying but a THD Trip is concurrently
required to trip and lockout, then the THD
Trip and Lockout has priority and should
Trip and Lockout the capacitor bank. No
further retries would be allowed in this
case.
• If the capacitor bank just Closed and
Neutral Current results in the capacitor
bank reversing and blocking and a THD
Trip is concurrently required to Trip and
Lockout, both features would have the
end result of an Open and Locked out
capacitor bank so there is no conflict.
Whichever feature in this case times out
first would Trip the capacitor bank and
apply a lockout. The other feature would
then only apply the lockout.
Summary of Contents for M-6280A
Page 1: ...Instruction Book M 6280A Digital Capacitor Bank Control ...
Page 33: ...This Page Left Intentionally Blank ...
Page 53: ...xx M 6280A Instruction Book This Page Left Intentionally Blank ...
Page 56: ...Introduction 1 1 3 Figure 1 1 Functional Diagram ...
Page 59: ...1 6 M 6280A Instruction Book This Page Left Intentionally Blank ...
Page 66: ...2 7 Operation 2 Figure 2 1 M 6280A Front Panel ...
Page 137: ...3 14 M 6280A Instruction Book Figure 3 13 CapTalk Main Screen Connected Mode ...
Page 172: ...3 49 CapTalk 3 Figure 3 67 CBEMA Settings Dialog Screen ...
Page 179: ...3 56 M 6280A Instruction Book Figure 3 87 M 6280A DNP Configurator Dialog Screen ...
Page 184: ...3 61 CapTalk 3 Figure 3 98 CapPlot Window with Data Logging Data Example ...
Page 185: ...3 62 M 6280A Instruction Book Figure 3 99 CapPlot Window with Oscillograph Data Example ...
Page 191: ...3 68 M 6280A Instruction Book This Page Left Intentionally Blank ...
Page 313: ...M 6280A Instruction Book 4 122 Figure 4 63 Setpoints Dialog Screen VAr Control ...
Page 314: ...Configuration 4 4 123 Figure 4 64 Setpoints Dialog Screen Current Control ...
Page 451: ...D 4 M 6280 Instruction Book This Page Left Intentionally Blank ...