OPERATION |
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PROGRAMMING
The generator set will start operating, acquiring this load, when network power
consumption is detected which more than the limit set by parameter (Threshold
table, parameter 34). The genset will continue to operate until the genset power
consumption measured falls below a limit set by parameter (Thresholds table,
parameter 35). Both with the start and stop of the genset due to load demand,
the conditions must be validated for a programmable time (Times table,
parameter 27). The function of start up due to load demand is only enabled in
Automatic mode of the CEM7 control unit associated to a switching control unit
CEA7CC2.
NOTE
From the firmware versions of control units: Display 3.20 / Measurements 2.50
4.8 ELECTRONIC PROTECTION
DESCRIPTION
The electronic protection is a feature that permits a control unit output to be
activated in the event of an overload and short circuit alarm. This function allows
the genset's main circuit breaker to be disabled via the trip coil. While any of
these alarms that causes the engine to stop (immediate or cooling) remains
active or pending notification, the output assigned to electronic protection
remains active.
PROGRAMMING
The possible outputs that can be assigned to this function are:
•
The SC relay is assigned by default to this function. Furthermore, the
SC relay is also activated when any alarm is generated which causes
the engine to stop.
•
The BT relay of the measurements module (Regulations table,
parameter 4).
•
Any of the programmable outputs of the measurements module
(Settings table, parameters 1 to 3).
4.5.2 DYNAMO MODE
Operation of the CEM7 control unit's battery charging alternator configured in
dynamo mode, excites the alternator via a continuous pulse through the D+
output of the measurements module while the engine is in start up phase or is
running.
The control unit configured in dynamo mode cannot use the voltage measured via
the DI analogue input for detecting an engine running condition.
The CEM7 control unit can be configured to produce an Alternator Voltage alarm
(Alarms table, parameters 10 to 12) if a low voltage supplied by the battery
charging alternator is detected through the DI analogue input of the
measurements module if it is set to alternator mode.
4.6 START/STOP KEY
The start/stop key in the ON position causes power to be supplied to the CEM7
control unit's electronic devices (measurements module and display module).
The start/stop key in the OFF position causes a controlled stop if it is running;
once the engine has stopped, power to the CEM7 control unit is disconnected.
4.7 START DUE TO LOAD DEMAND (ONLY CEA7CC2 EXPANSION)
DESCRIPTION
This function enables automatic start up and activation of generator set charging
depending on the power consumption of the network.
The start up is performed according to the programming, considering the
maximum power (Threshold table, parameter 34) the network can consume for a
period of time (Times table, parameter 27). Once the generator set is started,
the system changes genset power leaving the network free of load.
When the load in the installation is below the programmed threshold (Threshold
table, parameter 35) for deactivation and the programmed period of time (Times
table, parameter 27) has elapsed, the system returns to charging the installation
via the network and the genset begins its stopping cycle.
