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Reglermanual - VMGFF102
The slave unit must stay in CCN operating type continuously. To
stop the master/slave assembly, select Local Off on the
master unit or use the remote volt-free contacts if the unit
has been confi gured for remote control.
One of the functions of the master unit (depending on its
confi guration) may be the designation, whether the master
or slave is to be the lead machine or the follower. The roles of
lead machine and follower will be reversed when the
diff erence in running hours between the two units exceeds a
confi gurable value, ensuring that the running times of the
two units are automatically equalised.
The changeover between lead machine and follower may
take place when the assembly is started up, or even whilst
running. The running time balancing function is not active if
it has not been confi gured: in this case the lead machine is
always the master unit.
The lead machine will always be started fi rst. When the lead
machine is at its full available capacity, start-up delay
(confi gurable) is initialised on the follower. When this delay has
expired, and if the error on the control point is greater than
1.7°C, the follower unit is authorised to start and the pump is
activated. The follower will automatically use the master unit
active setpoint. The lead machine will be held at its full
available capacity for as long as the active capacity on the
follower is not zero. When the follower unit receives a
command to stop, its evaporator water pump is turned off
with 20 seconds delay.
In the event of a communication fault between the two units,
each shall return to an autonomous operating mode until the
fault is cleared. If the master unit is halted due to an alarm,
the slave unit is authorised to start without prior conditions.
ATTENTION: For heat pumps operating in master/slave
mode and using an NRCP2 board or equipped with electric
heater stages control must be on the entering water
temperature.
6 DIAGNOSTICS TROUBLESHOOTING
6.1 - General
The control system has many fault tracing aid functions. The
local interface and its various menus give access to all unit
operating conditions. If an operating fault is detected, an
alarm is activated and an alarm code is stored in the Alarms
menu, sub-menus CUR_ALRM and ALARMRST.
6.2 - Displaying alarms
The alarm LED on the interface (see chapter 4.1) allows the
quick display of the unit status.
• A
fl ashing LED shows that the circuit is operating but
there is an alert.
•
A steady LED shows that the circuit has been shut down
due to a fault.
The ALARMRST menu on the main interface displays up to
fi ve fault codes that are active on the unit.
6.3 - Resetting alarms
When the cause of the alarm has been corrected the alarm
can be reset, depending on the type, either automatically on
return to normal, or manually when action has been taken on
the unit. Alarms can be reset even if the unit is running.
This means that an alarm can be reset without stopping the
machine. In the event of a power supply interrupt, the unit
restarts automatically without the need for an external
command. However, any faults active when the supply is
interrupted are saved and may in certain cases prevent a
circuit or a unit from restarting.
A manual reset must be run from the main interface via the
ALARMRST menu, item RST_ALM. Depending on the
confi guration in the GENCONF menu, access to the item may
be protected by a password.
Summary of Contents for AR05
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