N
egative temperature cold room
This control is equipped with two sensors, one for the
control of the refrigeration unit, the other senses the
evaporator temperature.
Defrost functions
Defrost cycle is initiated by a timer and
terminated either by temperature or time,
whichever comes first.
The defrost function includes the following
parameters:
•
Type of defrosts (Hot gas or electrical heating).
•
Interval time to adjust defrost frequency.
•
Type of defrosts termination: time or temperature.
•
Defrost end temperature.
•
Maximum defrosts duration.
You can stop the compressor for an additional
configurable period called dripping time. This will
allow the evaporator to dry prior to resuming normal
operation.
In case of evaporator sensor failure, defrosts
cycle will be terminated by the maximum defrost
duration.
During defrost the display can be configured to show the
last measurement before defrost or the setpoint.
Fan management functions
Through the controller, you can choose whether
the fan is to be run in parallel to the compressor
or constantly ON. In any case the fan is switched
OFF during defrost.
After defrost, the fan can resume its work after a
preset time or after the evaporator temperature
has dropped below a user-settable temperature.
Condensing fan or door frame heater
On the 3-phase models, two terminals are
available to field connect a condensing fan or a
door frame heater to avoid the cell door sticking.
Digital input functions
All defrost controllers are equipped with an
additional digital input which can be configured to
perform the following functions:
•
“Shut-OFF”
function.
•
External alarm function.
•
“Door open” function.
Pump down selection
A selector is available to choose between the
start stop strategy for the compressor
Note:
A detailed list of available parameters and their
description can be found at the end of this
documentation.
Negative Temperature Cold Room Cabinet
Selection table:
Item code
Power
supply
Compressor
Evap.
Fan
Cond. Fan/
Door frame
heater
Defrost
Cabinet
Size
Shipping
weight
V ac
Φ
Φ
Φ
Φ
Power
AC-3
Amps
Amps
Amps
Amps
modules
Kg
CR-NS037-1
230
1
0,37 kW
5
1,6
-
8
12
2,5
CR-NS075-1
230
1
0,75 kW
8
1,6
-
12
12
2,5
CR-NS110-1
230
1
1,1 kW
10
3,2
-
12
12
2,5
CR-NS150-1
230
1
1,5 kW
12
4,8
-
16
12
2,5
CR-NT150-1
400
3
1,5 kW
3,5
3,2
3
12
18
3,5
CR-NT250-1
400
3
2,5 kW
5,7
3,2
3
12
18
3,5
CR-NT400-1
400
3
4,0 kW
8,5
4,8
3
15
18
3,5
CR-NT550-1
400
3
5,5 kW
11,5
4,8
3
15
18
3,5
CR-NT750-1
400
3
7,5 kW
15,5
4,8
3
15
18
3,5
Solenoid valve and
compressor
switched in parallel
Pump down
6
CR1
Catalogue Section 9
© 2000 Johnson Controls, Inc.