Bulletin 100-50-9.1 –
Page 21
on the controller. See the following figure
. Note: Ensure
that the wiring from the LED matches the output on
the controller (ground to ground, etc). Tighten the
terminal screws to 3-5 in.-lb. Carefully tug the leads
to ensure they are secure.
5.4.9 CT SENSOR
5.4.9.1 MOUNTING
The CT sensor is used when defrost current detection is
required (electric heaters). The split core design allows
the sensor to be installed after final wiring. One leg of the
defrost heater circuit must be ran through the CT. Secure the
CT to the wire with two zip ties as shown.
Note: In many
cases, it is necessary for the S3C to pilot a defrost
contactor. It is important to install the CT sensor on
the heater circuit, not the pilot circuit.
5.4.9.2 WIRING
Using 22-24 AWG wire, attach two leads to ‘L’ and ‘K’ on
the CT as shown in next image. Tighten CT wire screws 10-
12 in.-lb. Carefully tug the leads to ensure they are secure.
With controller unpowered, carefully route the CT leads to
the controller. Take caution to route the cable away from
sharp edges. Ensure the terminal screws on the controller
are backed all the way out. Insert the ‘K’ and ‘L’ leads of the
sensor wire into “Auxiliary” location on the controller as
shown below. Leads are polarized and require the proper
position on the controller. Tighten the terminal screws to 3-5
in.-lb. Carefully tug the leads to ensure they are secure. See
the following figure.
Note: The “Auxiliary” temperature
input can be used for the CT or another temperature
sensor such as case surface temperature. The
controller will need to be configured on which sensor
is used. See Section Defrost Configuration Section
for configuration of this input.
5.5
DUAL TEMPERATURE SWITCH
5.5.1 MOUNTING
A dry contact switch may be used to initiate dual
temperature mode on a case or line-up. The switch may be
located in the mechanical room or on the case. Follow the
switch manufacturer’s installation instructions.
5.5.2 WIRING
With controller unpowered, carefully route the dual
temperature switch cable to the controller. Take caution to
route the cable away from sharp edges and hot or moving
objects. Ensure the terminal screws on the controller are
backed all the way out. Under the “Digital Inputs” section
on the controller, insert one lead of the switch into “Ref”.
Insert the other lead into “User”. The leads are not polarized
and may be placed in either location. Tighten the terminal
screws to 3-5 in.-lb. Carefully tug the leads to ensure they
are secure. See the following figure.
Note: For line-ups, it is only necessary to wire the
switch into one of the case controllers. The “User”
digital input may also be configured to initiate defrost.
See Section 11.7 on configuring this input.
5.6
DOOR SWITCH (WALK IN FREEZER/
COOLER)
5.6.1 MOUNTING
A door switch may be used on walk in cooler/freezer
applications that require the refrigeration to shut off during
door openings. The additional switch may also be used to
alarm if the door is accidentally left open. The S3C Case
Control supports a normally open switch, or “dry contact”.
For rugged environments, it is recommended to use an
Amseco/Potter ODC-59A or equivalent switch; see Figure
below (courtesy of Amseco/Potter). Follow the switch
manufacturer’s recommendation for mounting to the walk
in cooler/freezer door and frame.
Note: The “L” bracket
attaches to the door.
L
K
