InteliGen
NT
, InteliSys
NT
, InteliMains
NT
– Troubleshooting Guide,
SW version IGS-NT-3.1.0, IM-NT-3.1.0, ©ComAp
– August 2018
14
IGS-NT Troubleshooting Guide.pdf
Synchronizing, Load control
Gen-set voltage is increasing/decreasing over/under the limits during
synchronization
Problem:
When gen-set is synchronizing to the Bus/Mains its voltage goes out of limits and GCB is
opened due to over/undervoltage protection.
Solution:
a) Check setpoints
GenNomV
or
GenNomVph-ph
if they are adjusted to proper value.
b) If the voltage is adjusted properly check if the same value is in
MainsNomV/BusNomV
or
MainsNomVph-ph/BusNomVph-ph
.
These values need to be adjusted to the same value
even if nominal voltages of gen-set and Bus/Mains are different!
c) See the example below for proper adjustment of system with different nominal voltages on
Mains/Bus and gen-set.
Example:
Both setpoints
GenNomV
or
GenNomVph-ph
and
MainsNomV/BusNomV
or
MainsNomVph-
ph/BusNomVph-ph
must be adjusted to the same values according to the value of actual
generator nominal voltage. E.g. gen-set nominal is 231 V but Bus/Mains nominal is 240 V.
-
In this case both setpoints need to be adjusted to 231 V and setpoints of corresponding
protections for Bus/Mains need to be set assymetrically.
-
For 240 V on Bus/Mains it is typical to open MCB when voltage reaches 254 V or 225 V.
-
Since the setpoint for Mains/Bus nominal voltage is adjusted to 231 V corresponding
protection setpoints need to be adjusted to
Mains >V/Bus >V
= 106% and
Mains <V/Bus
<V
= 97 % (hence the desired values are reached).
GCB is opened before the Load ramp time is over
Problem:
After reverse synchronization and during generator unloading is GCB opened before the Load
ramp time is over.
Solution:
a) AMF settings
:
BreakerOverlap
time is shorter than the
Sync/Load ctrl
:
Load ramp
time
setting. Set
Breaker overlap
to the same or longer time than
Load ramp
setpoint.
b) GCB is opened during generator unloading as soon as generator power level given by
setpoint
Sync/Load ctrl
:
GCB open level
is reached. Decrease the
GCB open level
setting to
avoid premature GCB opening.
c) Load in island was much lower than gen-set nominal power. The real time of load ramp is
Load ramp
x Pinitial_island /
Nomin power
; controller switches off GCB immediately (with 1s
delay) as soon as generator power gets below the
GCB open level
.
Sync fail alarm is issued
Solution:
a) Setpoint
Sync/Load ctrl
:
Sync timeout
is set to too short time -> set it to a longer time to allow
controller to match all synchronizing conditions.
b)
Speed governor or AVR control is not setup correctly. See chapters
Speed Governor Interface
List
and
AVR Interface List
in IGS-NT Installation Guide for information about proper
connection of a speed governor and AVR. See
Sync/load control adjustment
and
Volt/PF
control adjustment
chapters
in an IGS-NT Reference Guide for information how to setup
controller speed and voltage regulation loops correctly.
MGCB is not closed even all conditions are fulfilled
Solution:
a) IM-NT
Bus protect
: Bus >V Hst, Bus <V Hst, Bus >f, Bus <f do not have the same settings as
IG/IS-NT generator control unit (use the same settings for generator and mains control unit).
b) IM-NT and other gen-sets are not in the same logical group. See setpoints
Pwr Management
:
Control group (Controller cannot see each other via CAN bus).
