Carel µC2SE User Manual page 59

HP1: High pressure circuit 1
The alarm is detected irrespective of the status of the pump and the compressors. The compressors
corresponding to circuit 1 are immediately stopped (ignoring the set protection times), the buzzer and
alarm relay are activated, and the display starts fl ashing. The fans corresponding to the condenser in
circuit 1 are activated at maximum speed for 60 s, so as to oppose the alarm situation, after which they
are switched OFF. This alarm may also be generated when the high pressure limit is exceeded (valid only
when the pressure transducer is fi tted) set by the parameter P18, which to be enabled must be greater
than 3.0 bars, due to the corresponding hysteresis.
HP2: High pressure circuit 2
As for HP1 but relating to circuit 2.
LP1: Low pressure circuit 1
The alarm depends on P15, P7 and P3.
P15= 0, P07= 0: the alarm is detected only if the compressors in circuit 1 are ON, and after the time P03
from when the compressors started, otherwise it is immediate.
P15= 1, P07= 0: the alarm is detected even if the compressors in circuit 1 are off, after the time P03.
P15= 0, P07= 1: the alarm is detected only if the compressors in circuit 1 are ON, and after the time P03
from when the compressors started, otherwise it is immediate, and if in heat pump mode, is activated for
pressure values less than 1 bar.
P15= 1, P07= 1: the alarm is detected also if the compressors in circuit 1 are Off, after the time P03, and
if in heat pump mode, is activated for pressure values lower then 1 bar. The hysteresis for this alarm is 1
bar.
LP2: Low pressure circuit 2
As for LP1 but relating to circuit 2.
PL1: Capacity-control for low pressure circuit 1
Indicates that circuit 1 on the unit is operating in capacity control mode, due to low pressure (heat pump only).
PL2: Capacity-control for low pressure circuit 2
As for PL1, but for circuit 2.
PH1: Compressor part load circuit 1
Indicates the part load of circuit 1 due to high pressure. This situation is signalled by the message "PH1"
on the display the activation of the warning relay.
PH2: Compressor part load circuit 2
As for PC1, but for circuit 2.
tP: General thermal overload
The alarm is detected irrespective of the status of the pump and the compressors. The compressors, the
pumps and fans stop (without observing the protection times) or are inhibited from starting, the alarm
relay is activated, the display fl ashes the corresponding message, and the LED fl ashes. It can be reset
either manually or automatically (see par. P08, P09, P10, P11, P12, P13).
tC1: Thermal overload circuit 1
As for tP but relating to circuit 1
tC2: Thermal overload circuit 2
As for tC1 but relating to circuit 2.
LA: generic warning
This represents a generic warning that appears on the display, from digital input, without modifying the
operation of the unit. With the 1st circuit module only, the alarm relay is activated, while with the
expansion card the warning relay can be used.
FL: fl ow alarm
This alarm is detected only if the pump is ON (excluding the delays when starting P01 and in steady
operation P02), irrespective of the status of the compressor. All of the outputs are disabled: pump,
compressor (without observing the OFF times), condenser fan, and the buzzer sounds, the alarm relay is
activated and the display fl ashes. The presence of the utility water pump must be enabled (H5≠0). It can
be reset either manually or automatically (see P08, P09, P10, P11, P12, P13).
FLb: Backup pump warning
The warning activates the warning relay and displays the message "FLb"; reset is manual. This indicates
the operation of the backup pump (if present) due to a probable fault on the main pump, suggesting that
maintenance is required. If the fl ow alarm features automatic reset, the controller will make 10 attempts
to re-start the pumps, after which the FL alarm will replace FLb. If the fl ow alarm features manual reset,
when fi rst activated the controller will display the alarm FLb, switching over the pumps; when activated
again the FL alarm will replace FLb.
E1 to E8: probe error detected even when the unit is in Standby
The presence of a probe alarm causes the deactivation of the compressor, the condenser fans, the pump
(outlet fan in AIR/AIR units) and the heaters (so as to avoid fi res in the air/air units); the buzzer and alarm
relay are activated, and the display starts fl ashing. If the probe has a compensation function, the unit will
continue a operate correctly, with the exception of the corresponding function, and the warning relay will
be activated and a message shown on the display, from E1 to E8 for probes from B1 to B8.
µC 2 SE - +030220426 - rel. 2.0 - 03.08.2009 59