Woodward GCP-20 Series User Manual

Manual 37128A GCP-20 Series - Genset Control
Page 114/190 © Woodward
Unbalanced Load Monitoring
NOTE
All percentage values refer to a percentage of the generator rated power (Parameter 18; page 75).
Function: "Generator load imbalance not within the permissible range" - The percentage threshold value speci-
fies the permissible deviation of one phase current to the arithmetic mean value of all three phase currents.
Parameter 154
Load unbalanced
monitoring ON
Unbalanced load monitoring ON/OFF
ON................Monitoring for unbalanced load of the generator real power will be
performed. The subsequent parameters of this function are displayed.
OFF..............Monitoring is disabled, and the subsequent screens of this function
are not displayed.
Parameter 155
Load unbalanced
max. 000%
Maximum permissible unbalanced load 0 to 100 %
If the threshold value has been exceeded for at least the delay time (Parameter 156;
e.g. because of an asymmetric load), the following alarm class is initiated.
Issuing of class F3 alarm
Example 1
I
rated
= 100 A
I
unbalanced
= set to 33 %
The monitor responds, if the difference between a phase and the arithmetic mean value of all three phases is
(100 A × 33 %)/100 % = 33.3 A. The arithmetic mean value of all three phases is calculated by: 33.3 A × 3 = 100 A. In case
of an alarm (one phase defective) the two remaining phases take over 100 A each. The current within the two remaining
phases is calculated as follows: 100 A/2 phases = 50 A per healthy phase.
Reading on the display: 0/50/0; 70/30/0; 45/55/0; etc.
Example 2
I
rated
= 100 A
I
unbalanced
= set to 90 %
- (100 A × 90 %)/100 % = 90 A
- 90 A × 3 = 270 A
270 A/2 phases = 135 A per healthy phase.
Indication on the display: 135/135/0; 130/140/0; 120/150/0; etc.
Parameter 156
Load unbalanced
delay 00.00s
Unbalanced load monitoring delay 0.02 to 99.98 s
For the control unit to recognize an unbalanced load monitoring fault condition, the
threshold value configured in
Parameter 155 must be exceeded without interruption
for this period of time.

Woodward GCP-20 Series Specifications

General

Brand	Woodward
Model	GCP-20 Series
Category	Control Unit
Language	English