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SECTION 28 - HEAT RECOVERY
FORM 160.54-M1
ISSUE DATE: 10/25/2019
JOHNSON CONTROLS
JCI COMPANY CONFIDENTIAL
28
REMOTE HOT WATER SETPOINT
The Hot Water setpoint can be remotely changed based
on the chiller’s Control Source setting. The Active Hot
Water setpoint will contain the actual setpoint being
used for Hot Water Control. The following table shows
what setpoint is used based on the Control Source.
The allowable range for the Active Hot Water setpoint
is the same as the Local Hot Water setpoint. If a remote
value is received that is greater than the maximum, the
active setpoint shall be set to the maximum. If a remote
value is received that is less than the minimum, the ac-
tive setpoint shall be set to the minimum. The Remote
Hot Water setpoint Input Type selects the type of input
signal to be used (0-10V or 4 to 20mA) when the Con-
trol Source is set to Analog.
The Remote Input Type setpoint is used to configure
the LTC I/O Board input TB9-3/4 to accept either a 0
to 10 VDC or 4 to 20mA input for the Remote setpoint
input. This setpoint must be set to the same value for
the actual input applied. Otherwise, the remote setpoint
will not be interpreted correctly. The Active Hot Water
setpoint data box displays the remote setpoint that is
in effect.
CONDENSER FLOW SWITCH OPEN FAULT
The CONDENSER-FLOW SWITCH OPEN Cycling
Shutdown is changed when Heat Recovery is enabled. It
shall shut the unit down only if both the Condenser Flow
Switch and the Heating Condenser Flow Switch are open
using the same timing as in the current logic. If either flow
switch is closed, the chiller will not shut down.
TABLE 23 -
CONTROL SOURCE SETPOINTS
ACTIVE HOT
WATER SETPOINT
CONTROL SOURCE
INPUT
DESCRIPTION
Hot Water Setpoint
Local and Digital
Heat Recovery
Screen
Locally programmed value
Remote Hot Water
Setpoint
BAS
YORK Talk III Comms
Remote value via communications
(GPIC List)
Remote Hot Water
Setpoint Offset
Analog
Analog Input
Offset added to local Hot Water Setpoint
0V = -0°F offset, 10V = -20°F offset
4mA = -0°F offset, 20mA = -20°F offset