Carel easy, User Manual

Page: 20 / 32

20
GB
easy/easy compact +030220791 - rel. 2.0 - 30.05.2007
r3 contact result
0 open Direct operation with defrost control
closed Reverse operation
1 open Direct operation
closed Reverse operation
2 open Direct operation
closed Reverse operation
Table 4.j
A4= 10 Probe for dirty condenser alarm
Multifunction analogue alarm input and dirty condenser pre-alarm, using
the third probe.
To enable this function, set:
the third probe (see par. “2.2 Electrical connections” page 9);
parameter Ac: temperature set point above which easy signals the
dirty condenser alarm;
parameter AE: temperature diff erential that, together with Ac,
determines the dirty condenser pre-alarm;
parameter Acd: dirty condenser alarm signal delay;
parameter A4=10: enable the probe and dirty condenser alarm.
“cht” dirty condenser pre-alarm:
indicates that the limit between Ac and AE has been exceeded
(deriving from the calculation: Ac-AE/2, see Fig. 4.l);
easy continues normal operation;
automatic reset (if the temperature measured by probe 3 falls below
Ac-AE);
“cht” is shown on the display, alternating with the current
temperature.
“CHt” dirty condenser alarm:
indicates that the temperature set point Ac has been exceeded (see
Fig. 4.l);
the delay time Acd has elapsed;
easy stops all functions;
the buzzer sounds (to mute this, press SET or to disable deactivate set
H4=1);
“CHt” is shown on the display, alternating with “cht” and the current
temperature.
Important: the “CHt” alarm (see par. “5.1 Table of alarms and
signals” on page 23) can only be reset manually, or alternatively by
switching the controller off , pressing UP for 3 s or powering down (on
power-up, if the temperature is still above the “Ac”, the alarm will go off
again).
AC-AE/2
AC-AE AC
1
2
3
Fig. 4.l
Key:
1 condensing temperature;
2 “cht” pre-alarm, display only (automatic reset)
3 “CHt” alarm and refrigeration “OFF” (manual reset)
;
A4= 11: Product probe
3rd input (terminal 11) confi gured as product probe
The input is used in analogue mode for probe 3 (product).
Below is a summary table of the relation between parameter A4 and the
actuators:
outputs
alarm AUX FAN COMP
A4= 1 ”IA” - - -
A4= 6
P
- -
A4= 7 ”dor”
P P
-
A4= 8 ”dor”
P P P
Table 4.k
1.
2.
3.
4.
5.
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A7: digital input alarm delay
Sets the delay (in minutes) for detecting the external alarm when A4=
1, 7 or 8.
A8: enable alarm “Ed” (end defrost by timeout)
The alarm ‘Ed’ signals the end defrost due to the “maximum defrost time”
(dP) being reached. This can be disabled, by setting A8=0.
The signal “Ed” disappears when the next defrost is called.
Ac: Dirty condenser alarm set point
Sets the temperature set point above which the dirty condenser alarm
“CHt” is signalled (see parameter A4=10).
AE: Dirty condenser alarm diff erential temperature
Sets the temperature value for determining the dirty condenser pre-
alarm “cht” interval (see parameter A4=10).
Acd: dirty condenser alarm delay
Sets the delay in minutes before activating the dirty condenser alarm
“CHt”’ (see parameter A4=10).
4.9 Evaporator fan management parameters
The fan is activated based on the parameter settings and the status of
the controller.
The evaporator fan control temperature is measured by probe 2,
(connector 10).
To know which output is associated with the fan, see the wiring diagram
for the “easy” model used (see par. “2.2 Electrical connections” page 9).
Important: these parameters are not available in the compact
models.
In normal operation, the evaporator fan can be managed as follows:
always on (F0= 0);
on according to the evaporator temperature (F0= 1; F1);
off when the compressor is off (F2= 1).
During defrost, the status of the evaporator fan is determined by
parameter F3:
controlled according to F0 (F3= 0);
off (F3= 1).
The fan remains off :
during the dripping period, if parameter dd≠0;
during the post-dripping period, if parameter Fd≠0;
for a time equal to c0 after instrument power-on, if parameter c0≠0.
F0: enable evaporator fan control
F0= 0 the fan is on;
F0= 1 the fan is controlled based on a set point (see parameter F1). If
the evaporator probe is faulty, the fan operates.
F1: evaporator fan control set point
The controller starts the fans only when the temperature of the evaporator
is below the value F1-A0. F1 is the real temperature value and not the
deviation from the set point. Once off , the fans start again when the
diff erence between the probe reading and the set point is equal to +A0,
where A0 is the fan controller diff erential.
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