dU
First defrost cycle after power-on:
This parameter allows to delay a defrost cycle,
after power-up. This will prevent a cycle from
occurring before the cold room has reached its
operation temperature.
When set to ‘OFF’, the first defrost will occur
after a complete defrost interval (parameter di)
dP
Display during defrosts:
You can select what to display during the defrost
cycle. This is meant to avoid misleading users
during the defrost cycle.
0 = last measured value before defrost cycle
1 = setpoint
dr
Delay displayed temperature after defrost
During defrost cycles the ambient temperature is
not displayed (see parameter dP). The actual
temperature returns to display when its value
reaches the setpoint value or, in any case, after
the time defined by this parameter.
iF
Digital input function:
The digital input (normally closed) can be
configured according to the plant requirements:
0= the DI is not connected
1= If the contact is open for a time longer than that
set through parameter id, the plant is switched
OFF and an alarm message is displayed; this
can be used for condenser alarm...
2= Alarm function: in this case an alarm message
is displayed and the alarm digital output is
switched ON
3= Open door in the cold room. When the contact
is open, the fan is switched OFF (when
applicable) and if the contact is open for more
than the time set through parameter id an alarm
message is displayed and the alarm output is
switched ON. High and low alarms are disabled.
id
Digital input time delay:
Time between the detection of the digital input
opening and the enabling of the function
selected through parameter iF.
FF
Fan operating function:
0= fan runs in parallel to the compressor
1= fan is always ON
Note: in both cases, the fan is switched OFF
during the defrost cycle.
Fd
Fan start-up delay after defrost end:
This parameter is a safety function, the fan is
activated after this time even if the temperature
set through parameter Fr has not been reached
Fr
Fan start temperature after defrosts end:
Evaporator sensor temperature at which the fan
is switched ON, after defrost cycle,
Note: in any case the fan is switched ON after
the time set through parameter Fd.
SF
Thermostat operating function when sensor
failure:
This defines the cycle of the thermostat output in
case of failure
0 = Compressor ON
1 = Compressor OFF
2 = Automatic
In this mode, the controller will calculate the
average time the compressor was ON for the
last 4 cycles, and the compressor will run
accordingly. If a deep freezing cycle or a defrost
cycle occurred, they will not be taken into
account nor will the first cycle afterwards.
So
Offset thermostat sensor:
This value is added to or subtracted from the
measured value to compensate for possible field
measurement offset errors. To compensate for
extra long copper cabling use the following
formula:
5
length
1
area
= −
×
×
K
0 0 0
C om p ens ation
Where:
length = length of the cable in meters
area = section of the cable in square millimetres
and compensate for the calculated value
Un
Temperature units:
0 = Celsius degrees,
1 = Fahrenheit degrees.
PU
Display updating time delay:
The temperature value displayed will be
refreshed with this defined period. It will not
affect the control performance.
CR1
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© 2010 Johnson Controls, Inc.
Catalogue Section 9