Determination of leading or lagging in delta-
connected regulators
For a regulator to operate properly when connected phase
to phase, it is necessary for the control to be programmed
with the correct regulator configuration in FC 41. It must be
determined whether it is connected leading or lagging. The
control aids the operator in making this determination.
1. Regulator must be installed.
2. POWER switch must be set to
INTERNAL
.
3.
V1
knife switch (and
V6
, if present) must be closed.
4. Knife switch C must be open. Current must be flowing.
5. CONTROL FUNCTION switch may be in any position
(
AUTO/REMOTE-OFF-LOCAL MANUAL
).
6. For regulator #1, set FC 41 to Delta Lagging and record
the Power Factor, FC 13.
7. For the same regulator, set FC 41 to Delta Leading and
record the Power Factor.
8. Repeat steps 6 and 7 for each regulator in the bank.
9. For each regulator, one of the two power factor values
will be reasonable and the other will be unreasonable.
10. Set the Regulator Configuration (FC 41) to the value
which produced the reasonable power factor.
See
For one regulator:
Set FC 41 to the value which produced
the reasonable power factor.
For two regulators in open delta:
See the example in
. In an open delta connection, one of the regulators
will always be leading and the other lagging. The reasonable
power factor for each regulator should be very close to
the typical power factor of the system. In this example,
regulator #1 is the lagging unit and regulator #2 is the
leading unit.
For three regulators in closed delta:
In closed delta, all
three regulators are either leading or lagging, depending
on how they are connected relative to generator phase
rotation. Set FC 41 of all three regulators to the value which
produced the reasonable power factor.
Table 6 . Sample power factor values for regulators
connected in open delta configuration
Configuration (FC 41)
Recorded power factor (FC 13)
Reg. #1
Reg. #2
Delta Lagging
0.94*
-0.77
Delta Leading
0.17
0.93*
* Reasonable power factor values.
24
INSTALLATION, OPERATION, AND MAINTENANCE INSTRUCTIONS
MN225003EN April 2018
CL-7 Voltage Regulator Control