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SECTION 22 - REMOTE SETPOINTS
FORM 160.54-M1
ISSUE DATE: 10/25/2019
JOHNSON CONTROLS
JCI COMPANY CONFIDENTIAL
22
4 to 20mA
, connect input to
Microboard J22-4 (signal) and J22-5 (GND). A 4mA
signal produces a 0°F offset. A 20mA signal produces
the maximum allowed offset above the Local Setpoint
value (as allowed by the Remote Reset Temperature
Range setpoint). The setpoint is changed linearly be-
tween these extremes as the input varies over the range
of 4 to 20mA. This input will only be accepted when
Analog Remote Mode is selected, the Remote Ana-
log Input Range setpoint is set for 2 to 10 VDC and
Microboard Program Jumper JP24 has been placed on
pins 1 and 2. Calculate the setpoint for various inputs
as follows:
Offset (°F) = (mA–4)(Remote Reset Temp Range)
16
Setpoint (°F) = Local Se Offset
For example, if the input is 8mA, and the Remote Reset
Temperature Range setpoint is programmed for 10°F
and the Local Leaving Chilled Liquid Temperature
setpoint is programmed for 40°F, the setpoint would be
set to 42.5°F as follows:
Offset (°F) = (8–4)(10)
16
= (4)(10)
16
= 40
16
= 2.5°F
Setpoint (°F) = 40 + 2.5
= 42.5
PWM
The Pulse Width Modulation input is in the form of a
1 to 11 second relay contact closure that applies 115
VAC to the I/O Board TB4-19 for 1 to 11 seconds. As
shown in
, connect dry clo-
sure relay contacts between I/O Board TB4-19 (input)
and TB4-1 (115 VAC). A contact closure time (pulse
width) of 1 second produces a 0°F offset. An 11 second
closure produces the maximum allowed offset above
the Local Setpoint value (as allowed by the Remote
Reset Temperature Range setpoint). The relay contacts
should close for 1 to 11 seconds at least once every 30
minutes to maintain the setpoint to the desired value. If
a 1 to 11 second closure is not received within 30 min-
utes of the last closure, the setpoint is defaulted to the
Local setpoint value. A closure is only accepted at rates
not to exceed once every 70 seconds. This input will
only be accepted in Digital Remote Mode. Calculate
the setpoint for various pulse widths as follows:
Offset (°F) =
(pulse width in seconds – 1)(Remote Reset Temp Range)
10
Setpoint (°F) = Local Se Offset
For example, if the relay contacts close for 5 seconds
and the Remote Reset Temperature Range setpoint is
programmed to 10°F and the Local Leaving Chilled
Liquid Temperature setpoint is programmed for 40°F,
the setpoint would be set to 44°F as follows:
Offset (°F) = (5 – 1)(10)
10
= (4)(10)
10
= 40
10
= 4°F
Setpoint (°F) = 40 + 4
= 44°F
RS-232
, a setpoint can be
received in serial data form at the microboard COM 4B
serial port (J2) from the E-Link Gateway.
LEAVING CONDENSER LIQUID TEMPERATURE
(HEAT PUMP MODE)
(Software version C.OPT.01.23.307 (and later))
Heat Pump is an available option for certain models
of YK chillers. On a Heat Pump equipped chiller, with
Heat Pump Duty enabled, the chiller control can be
switched between Cooling and Heating Mode using
the Heat Pump Operational setpoint. In Cooling Mode,
the chiller controls the Leaving Chilled Liquid to the
leaving Chilled Liquid Temperature setpoint. In Heat-
ing Mode, the chiller controls the Leaving Condenser
Liquid Temperature to the Leaving Condenser Liq-