Carel pRack pR300T Mode D'emploi page 54

7. BEHAVIOUR IN THE EVENT OF PROBE FAILURE
Regardless of the selected function, up until software version 4.0.2, in the event of a fault on the temperature
probes, heat recovery was kept active.
Starting from software version 4.1.0, in order to ensure safe operation, in the event of a temperature probe
failure the software evaluates the possibility to disable heat recovery if the conditions to keep it active are
no longer present.
In particular, heat recovery will be disabled in the following cases:
•
If pump control is set to "temperature differential" and at least one probe (Two or Twi) is faulty or absent.
•
If pump control is set to "temperature" and the heat exchanger water outlet probe is faulty or absent.
•
If heat recovery control is set to "temperature" and the heat exchanger water outlet probe is faulty or
absent.
•
If heat recovery control is set to "external signal" but the signal is absent.
The table below summarises all of the possible combinations
HR
Control control
Digital Input
Digital input
Digital input
temperature
Temperature
Temperature
Temperature
temperature
External signal
External signal
External signal
temperature
Pump Two
probe alarm
x
HR req.
x
Delta T
x
Two
x
HR req.
x
Delta T
x
Two
x
HR req.
x
Delta T
x
Two
Twi External
probe alarm signal alarm
x
x
x
x
x
x
x
x
x
Heat
recovery
RUN
RUN
-
-
STOP - 0%
STOP - 0%
-
-
STOP - 0%
RUN
-
-
STOP - 0%
RUN
- -
STOP - 0%
STOP - 0%
-
-
STOP - 0%
RUN
- -
STOP - 0%
STOP - 0%
x
STOP - 0%
STOP - 0%
STOP - 0%
x
STOP - 0%
STOP - 0%
RUN
x
STOP - 0%
Pump
RUN
RUN
-
STOP - 0%
STOP - 0%
-
STOP - 0%
RUN
-
STOP - 0%
RUN
-
STOP - 0%
STOP - 0%
-
STOP - 0%
RUN
-
STOP - 0%
STOP - 0%
STOP - 0%
STOP - 0%
STOP - 0%
STOP - 0%
STOP - 0%
RUN
STOP - 0%
Tab. 7.a