Carel MuChiller UCHBD00001130, Руководство пользователя

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5.8
Compressor
alarms
Compressor shutdown
If abnormal conditions occur and the prevention actions are not effective, the compressor will be shut
down so as to avoid damage to the compressor itself or other unit components, i.e. the control algorithm
stops the compressors and closes the expansion valve.
The compressors will be available again after the:
l
minimum compressor off time (par. C013);
l
minimum time between consecutive compressor starts (par. C014).
User Code Description Def Min Max UOM
M C013 Min compressor off time 60 30 999 s
M C014 Min time between consecutive compressor starts 360 300 999 s
Compressor delay at
start-up/in operation
Compressor start-up is a critical phase. μChiller thus manages certain alarms differently, in order to switch
smoothly from start-up to normal, steady operation. These alarms are:
l
low differential pressure;
l
out of envelope alarm.
There are thus two delays for these alarms:
l
delay at start-up;
l
delay in operation.
The alarm condition is ignored when the compressor is off and during the start-up phase. When the unit
reaches steady operation, the condition causes the corresponding alarm once the delay has elapsed.
Behaviour will thus be as follows:
Fig.5.n
Key
Comp Compressor status
ALC Status of the alarm condition
ALS Alarm signal
D1 Alarm disabling from compressor start-up
D2 Alarm delay in operation
t Time
5.9
Power+ Speed
drive
When the unit is fitted with a BLDC compressor, this is controlled by the Power+ speed drive, connected
to the FBus serial port on μChiller via the Modbus master protocol with a baud rate of 19200 bps. Use a
specific cable for RS485 (AWG20-22 with 1½ twisted pair plus shield). See the Power+ instruction manual
+0300048EN.
5.10
Expansion valve
driver
The driver to manage the electronic expansion valve is a fundamental device for the μChiller controller.
This is used to safely manage the compressor and thus the circuit, constantly controlling the discharge
temperature and the position of the working point inside the compressor envelope. The solution
provided manages unipolar valves up to a certain cooling capacity (Carel E3V - cooling capacity up to 90-
100 kW) with the built-in driver (DIN model only) and bipolar valves with higher capacities, using the
external EVD Evolution driver. This must be connected to the FBus serial port on μChiller via the Modbus
master protocol with a baud rate of 19200 bps. Use a specific cable for RS485 (AWG20- 22 with 1½
twisted pair plus shield). See the chapter “Installation”.
Note: EVD Evolution is only used as an expansion valve positioner.
ENG
µC0300053EN rel. 1.0 – 23.07.2018
5. Functions | 61