EN - 36
●
If a fault occurs
- Compressors turned off.
- Fans turned off.
- Contact closes (board output 3) and turns on the evaporator heater (option).
- Machine fault relay on optional board in On position.
- General fault LED on console lit steadily.
- Display:
●
To acknowledge the fault
- The chilled water outlet temperature must be
the value of P52
+
2°C and
OK
must be pressed.
- The heater contact opens.
Evaporator antifreeze protection triggered by the evaporating temperature
-
If the saturation temperature on the evaporator outlet drops below P52
–
P70, the control will lower the compressor's output. If, after two
minutes, the saturation temperature remains below P52
–
P70, the circuit is turned off by its protection device.
-
If the evaporator saturation temperature drops below P52
–
P70 more than three times in 24 hours, the machine is turned off.
- Display:
Water loop winter protection
In heating mode
This function is available if P142 = Yes, the automatic machine control input is open, and On/Off set to On.
The function must maintain the condenser water inlet temperature at 30°C as soon as the outdoor temperature
3°C (2 K differential). The
control is identical to P141 = 1 with a control setpoint (P251) of 30°C.
The related parameter is
P142 (water loop winter safety)
Corresponding message:
In cooling mode
This function is available if P142 = Yes, Automatic pump control input open and On/Off set to On.
In this case:
- The pump cuts in when the outdoor temperature
P220.
- The pump cuts out at P220 + P222 or if the evaporator water inlet temperature
>
30°C (it cuts back in when the evaporator inlet temperature
<
20°C)
- Pump faults and reversals (depending on operating times) are managed.
Corresponding message:
In both modes of operation, winter protection mode is maintained if a fault occurs on the outdoor sensor.
In cooling mode, the function is activated if a fault occurs on the water inlet sensor.
Note:
water is circulated during freezing weather.
The customer must install a bypass on the system to avoid creating temperature conflicts during operation.
11. MANAGEMENT OF THE OUTPUTS OF LIQUID VALVES 1, 2 AND 3
These outputs may be used either to directly power an electric liquid valve
or to interlock the electronic expansion valve with the compressor. If the
outputs are used for either purpose, they must be controlled by a relay.
The liquid valve outputs are managed as each compressor cuts in.
The opening and closing of each output can be timed via the configuration
system (P61 and P62) or managed in relation to the low pressure level.
Operation
Cut-in:
-If P61 = 0, the output is energised while the compressor runs.
-If P61
0, the output is energised x seconds (P61) after the compressor
cuts in. This time delay is cancelled if the LP
P55
+
0.5 b (prevents a cut
in the LP).
Cut-out:
-If P62 = 0, the output is no longer energised when the compressor shuts
off.
-If P62
0
:
- If the compressor is shut off by a fault or by pressing the On/Off
button more than twice in 10 seconds, the output is de-energised when the
compressor shuts off.
- If the compressor is shut off by pressing the On/Of button once in 10
seconds or by the automatic operation control and in the other cases, the
output is de-energised x amount of time (P62) before the compressor shuts
off. During this period, if the LP
P55 + 0.5 b, the compressor is shut off
before the time delay elapses (prevents a cut in the LP).
12. MANAGEMENT OF THE ECONOMISER VALVES (HPS)
The control of the economiser outlets is interlocked with each refrigerating
circuit.
When the compressor cuts in, the corresponding HPS outlet is opened.
The economiser is shut off when its operation falls outside the compressor
curve.
- If the high pressure
>
P57, the HPS valve is closed and a 30-minute time
delay is activated.
At the end of this time delay, the condensing temperature is read:
- If the HP
P57, the HPS valve is opened.
- If the HP
>
P57, the 30-minute time delay is restarted and the HPS
valve remains closed.
The end result is that the condensing temperature is checked against P57
during operation.
Note
: The 30-minute time delay is disabled in test mode (= 0)
Liquid injection cooling of the compressor is accomplished by an interlock
with the operation of each compressor (electrical circuit diagram) instead of
by the electronic circuit board.
E V A P O R A T O R A N T I F R E E Z E
F A U L T
C I R C U I T X S T O P
E V A P . T . F R E E Z E F A U L T
W A T E R T E M P E R A T U R E
M A I N T A I N 3 0 °
W A T E R C I R C U L A T I O N
F O R C E D P U M P R U N N I N G