Novar NOVAR-1xxx NRC Operating Manual - page 10
Novar-NRC
KMB systems
10
Note 1 : The fifteen-minute average value of the active current Iact is not displayed, you can check
the actual value of the active current Iact only. So you must take in mind appriopriate delay in the
alarm activation and deactivation when checking its behaviour.
Note 2 : When this alarm is set , the undercurrent alarm (No. 1) is, as noted above, switched off,
necessarily. Therefore, the controller uses all of the sections but the fixed ones even if the measured
current drops to minimum. If you need the controller to set firmly defined combination of all the
sections when the alarm is activated, it is necessary to set as fixed all of the sections, not just those
that are to be fixed on, but the remaining sections as fixed off, as well.
The limit value setup example : Usually, it is necessary to set the current limit according required
active power threshold. CT ratio (par. 12,13 ) is set to 500/5A, type of measurement voltage (par. 15)
is phase-neutral (
U=LN
U=LN
U=LN
U=LN
), nominal voltage U
NOM
(par. 18) is 230 V. We intend to set the undercurrent
limit to correspond to the -5kW (export) of three-phase active power. Corresponding phase power is
-5 / 3 = -1.67 kW = -1670 W. As nominal voltage is 230V, corresponding phase current is 1670 / 230 =
-7.25 A (for phase-phase voltage, it must still be divided by √3). As one ppt of the current range is (as
in previous example) 0.5A, we set the parameter 33 to 7.25 / 0.5 =~ 15.
2.3.2 Alarm No. 15 – Remote Control Failure
For remote control mode state checking, alarm No. 15 was added :
Tab. 2.2 : Remote Control Failure Alarm
# condition
description
minimum delay
of
activation /
deactivation
actuation
15 remote
control
failure
loss of connection with the NRC86
unit/units ( some of the unit response
is incorrect or missing at all )
20 / 1 seconds
disconnection of all
sections
As default, the remote control failure alarm is switched off and it is possible to switch it on if advisable.
If no remote controlled outputs connected the actuation function is not interesting; it is intended
especially for emergency disconnection of remote controlled outputs. When temporary interruption of
the connection between the PFC and the NRC86 unit/units appears, the situation will look as follows :
1. Approximately after 20 seconds of communication link fault the PFC disconnects all of
outputs step by step and it will stay in standby mode until the connection is restored.
2. The NRC86 remote controller(s) in the I/O-mode disconnects (simultaneously) all of its
outputs after approx. 30 seconds of the communication link fault duration.
3. After the connection is restored, the PFC returns back to to control mode and the NRC86
controller(s) outputs starts to copy the PFCs outputs state to its outputs again.
So it is ensured that no premature switching of more outputs on will occur and the reconnection delay
time preset in the PFC will be kept