GE Industrial Solutions Galaxy Verification - Manual (Page 24)

Galaxy Power System Verification Procedures
2 - 12 Galaxy SC Controller Performance Verification Procedures Issue 3 January 2008
High Float Voltage Alarm/High Voltage Shutdown Alarm
Tests, continued))
HVSD Test
Procedure for
Serial Rectifiers
There are three requirements for a serial rectifier to shut down upon a
controller-initiated High Voltage Alarm:
• The plant voltage must be above the level set for HV at the front
panel path: <MENU>
→ CONFIG → THRESH.
• The rectifier must be delivering a current exceeding 10% of it's
capacity.
• The rectifier's current output must be unbalanced by more than 10%
from the average output currents of the other rectifiers. Because this
is difficult to achieve in a simulation test of properly functioning
serial rectifiers, even with load share disabled, rectifiers are tested
one at a time rather than as a group. Slightly different test
procedures are used for special applications in batteryless plants.
Serial rectifiers have their own internal restart circuits that will function
3 times before the rectifier locks itself out and initiates a High Output
Rectifier Fail Alarm to the controller. If there is a sufficient interval
between restart and a subsequent shutdown the rectifier resets its restart
counter.
The controller initiates a restart signal a few seconds after the first RFA
(HO) alarm is received. After the second RFA (HO) is received, the
controller waits 5 minutes before sending one additional restart signal.
Do not raise the plant bus voltage if an active load is being served. To
test HVSD under this situation, ensure that sufficient battery reserve is
connected to the plant bus to support the plant load. The battery may
start sharing some load and BD alarms may turn on during this test.