Single Loop Controller; Figure 43 - Single Loop Controller - York EX Series Installation, Operation & Maintenance Instructions Manual

FORM 155.32-ICOM1.EN.GB
ISSUE DATE: 10/13/2017

SINGLE LOOP CONTROLLER

The YHAU-CGN/H chiller-heater may have additional
controllers. Each SDC35 Single Loop Controller is lo-
cated to the left of the touch screen on the Control Pan-
el on the front cover of the unit. The maximum number
of units is two.
One use of the controller is to manage the air damper
of the burner unit. Another is to control the residential
hot water control valve. Separate controller units are
needed for each mechanism.
All of the information in the first three sections applies
to the unit no matter what it is controlling. Differences
based on the different mechanism will be covered in
the later sections.

FIGURE 43 - SINGLE LOOP CONTROLLER

Included on the controller are the following:
Upper Display: shows the process variable (PV)
mode or alternates between the display and set
values for each item. If an alarm is triggered, the
display changes. It alternates between an alarm
code and the normal information.
Lower Display: shows the set point or measured
variable or current transformer (SP/MV/CT) val-
ue. Or it alternates between the display and set
values for each item.
JOHNSON CONTROLS
Mode Indicator: lights to indicate which opera-
tional mode is active for the unit. The available
lights are:
a. Man: if the MAN light is not lit, the unit is
in AUTO mode. This is the manufacturer's
recommended setting. If the MAN light is
lit, it indicates that the unit is operating in
MANUAL mode. (This mode is available
only for the residential hot water use.) The
manufacturer does NOT recommend operat-
ing the unit in MANUAL mode.
b. Remote Set Point (RSP): Indicates that the
controller is using the remote set point infor-
mation.
c. EV1, EV2, EV3: Indicates that one or more
event relays are on.
d. OT1, OT2: Indicates that one or more con-
trol output is on.
Multi-Status Display (MS): Is lit when the unit
is in READY mode or when an alarm is triggered.
It functions as a MV graph, a Digital Input (DI)
monitor, and an internal event monitor as well. At
times, the display may flash.
Mode Key: Press and hold the key to choose from
any of 8 operational modes:
• 0: Mode key does not operate
• 1: Choose between AUTO or MANUAL
mode (available only for residential hot wa-
LD20934
ter control valve controllers)
• 2: Choose between RUN or READY mode
• 3: Start or Stop Auto Tuning (AT) control
mechanism
• 4: Choose the Local Set Point (LSP) mode
• 5: Releases all Digital Output latches
• 6: Choose LSP or RSP mode
• 7: Select between ON or OFF communica-
tion DI
SECTION 6 – OPERATION
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