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6 - DIAGNOSTICS - TROUBLESHOOTING
6.1 - GENERAL
The PRO-DIALOG Plus 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 Alarm menu.
6.2 - DISPLAYING ALARMS
The alarm LEDs on the summary interface (see section
4.1) give a quick display of the status of each circuit and
the unit as a whole.
✓
A flashing LED shows that the circuit is operating
but there is an alarm.
✓
A steady LED shows that the circuit has been shut
down due to a fault.
The Alarm menu on the main interface displays up to 5
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 using
the following procedure:
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.
5.15 - OPTIONAL HEAT RECLAIM MODULE
This option requires the installation of an additional board.
This board allows control of:
-
A heat reclaim condenser pump,
-
A heat reclaim condenser heater,
-
Two solenoid valves to shut off the heat reclaim coil
(one for each circuit),
-
Two solenoid drain valves for the heat reclaim coil
(one for each circuit),
-
Two solenoid valves to shut off the water condenser
(one for each circuit),
-
Two solenoid drain valves for the water condenser
(one for each circuit).
Selecting the heat reclaim mode can be done with either
the local interface or remotely with the (recl_sw) contact
or by CCN.
The heat reclaim function is active when: the heat reclaim
entering water temperature is lower than the heat reclaim
setpoint, minus half of the heat reclaim dead band.
The heat reclaim function is not active when: the heat
reclaim entering water temperature is higher than the heat
reclaim setpoint, plus half of the heat reclaim dead band.
In the dead band the function remains in its active mode.
The default value of the dead band is 4.4°C. This value
can be modified by Carrier Service.
Changeover procedure from cooling mode to heat reclaim
mode:
-
Start-up of the condenser pump.
-
Verification of the condenser flow switch control
contact. If this remains open after one minute of
condenser pump operation, the circuit remains in
cooling mode and an alarm will be activated.
-
As soon as the saturated condensing temperature
reaches 30°C, the pumpdown sequence is activated.
-
Pumpdown: opening of the condenser water inlet
valve and closing of the air condenser air valves 3
seconds later.
-
After one minute or when the subcooling value is
above -10°C the heat reclaim function is effective.
RESET OF ACTIVE ALARMS
OPERATION
ITEM NUMBER
ITEM VALUE
PRESS
MENU
2-DIGIT DISPLAY 4-DIGIT DISPLAY BUTTON LED
Hold down the MENU
button until the LED for
alarms lights. The 4-
digit display shows the
number of active
alarms (2 in this
example).
Press the Enter button
until "rESEt ALARrM" is
shown in the 4-digit
display.
Press the Enter button
again to validate the
reset. "Good" is
displayed for 2 seconds
then, "2 ALArM" and
then, "no ALArM".
0
0
2 ALArM
0
rESEt ALArM
0
Good
then, 2 AL
then, no ALArM
