Siemens MJ-XL Installation And Operation Manual page 49

F LOCK (Forward Locked Mode)
This mode of operation is intended for use on systems
where reverse power flow is not anticipated. Tap changes
are inhibited under reverse power flow conditions.
In this mode, the controller always operates in forward
mode. The tap changer operates unless reverse current
magnitude exceeds the I Threshold % setpoint, at which
time further tap changes are inhibited. The tap changer
resumes operation when the reverse current drops below
the I Threshold % setpoint.
If the I Threshold % setpoint is set to zero, the regulator
operates as above, using the 1% operational limits in
place of the I Threshold % setpoints.
In this mode, if power flow does reverse, Demand values
are not computed.
View Pwr Flow: F LOCK on the <CONFIGURE> Menu.
Reverse Current
Tap changes
inhibited
RPF indicator flashing
I Threshold % 1%
Current
Forward Locked Mode
Figure 6.2
Siemens Power Transmission & Distribution, Inc.
6
Forward Current
Tap changer operates
Tap changes resume
RPF indicator off
0 1%
MJ-XL Control Panel Automatic Mode
R LOCK (Reverse Locked Mode)
This mode of operation is intended for use on systems
where forward power flow is not anticipated. Tap changes
are inhibited under forward power flow conditions.
In this mode, the controller always operates in reverse
mode. The tap changer operates unless forward current
magnitude exceeds the I Threshold % setpoint, at which
time further tap changes are inhibited. The tap changer
resumes operation when forward current magnitude
drops below the I Threshold % setpoint.
If the I Threshold % setpoint is set to zero, the regulator
operates as above, using the 1% operational limits in
place of the I Threshold % setpoints.
In this mode, when power flow is Forward, Demand val-
ues are not calculated.
View Pwr Flow: R LOCK on the <CONFIGURE> Menu.
Reverse Current
Tap changer operates
Tap changes resume
Band indicators on
RPF indicator on
Reverse Locked Mode
Figure 6.3
Forward Current
Tap changes
inhibited
RPF indicator
flashing
Band indicators
flashing
1% 0 1% I Threshold %
Current
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