InteliGen
NT
, InteliSys
NT
, InteliMains
NT
– Troubleshooting Guide,
SW version IGS-NT-3.1.0, IM-NT-3.1.0, ©ComAp
– August 2018
16
IGS-NT Troubleshooting Guide.pdf
Example of correct Power management and Load shedding setting is on this
picture:
You can see that the
Pwr management
:
#%LdResStrt1
limit is crossed first when system load
goes up and request to start additional genset is issued before the load shedding request.
However, it is not enough to set limits in the suggested way to make system work properly. It
is important to set
Pwr management
:
#NextStrt del
much shorter than
Load shedding
:
Ld
shed delay
so there is enough time for starting genset to start, synchronise and take over load
before a load shedding output is activated.
MGCB is not closed although gensets are running
Problem:
All available gensets are running and connected to bus (GCB’s are closed), but IM-NT does
not close MGCB.
Reason of the problem is that Act Reserve (Actual load reserve) value is not higher than value
of currently used
Pwr management
:
LoadResStrt x
setpoint (binary input functions
Load res
x
can be used for switching between
LoadResStrt x
setpoints). Act Reserve has to exceed a
LoadResStrt x
value so IM-NT evaluates system reserve as sufficient to connect load to
gensets (this evaluation is not done when system should run in parallel with mains).
Check state of the Syst res OK signal in InteliMonitor (go to Values/Log Bout/LogBout 4) to
see if Act Reserve is evaluated by IM-NT as sufficient enough (condition for MGCB closing is
ActReserve >
LoadResStrt x
)
Solution:
a) Check if setpoint
Pwr management
:
Pwr management
is set to
ENABLED in genset
controllers (there is no such setpoint in IM-NT itself). Act Reserve value (P
BNom
) in IM-NT is
based on information it receives from gensets power management system. There is no
information about available power sent from gensets controllers to IM-NT if
Pwr
management
is set to
DISABLED.
b) Decrease value of a currently used
Pwr management
: #
LoadResStrt x
setpoint so available
Act Reserve (P
BNom
) is higher than the #
LoadResStrt x
setpoint. Do that if you consider
available Act Reserve power sufficient enough to cover a system load.
You can use alternative #
LoadResStrt x
setpoint with setting low enough to enable MGCB
closing (use a
Load res x
binary input function for switching to a different
LoadResStrt x
setpoint).
c) Set
Pwr management
: #
LoadResStrt x
setpoint to a negative value if you can not set
Pwr
management
:
Pwr management
setpoint to ENABLED in gensets controllers (e.g. IGS-NT-
LSM+PMS dongle is not used in genset controllers and power management function is not
available then). It is necessary to fulfill the following condition to enable MGCB closing:
P
BNom
> P
Akt
+ Reserve
P
BNom
Sum of the nominal power of all running gen-sets (displayed as Act Reserve
value by IM-NT)
