System Inputs; Analog Inputs; Figure 56 - Options Key; Table 20 - System Input Connections - York YVWA Installation Operation & Maintenance

SECTION 3 - HANDLING, STORAGE, INSTALLATION AND REASSEMBLY
Run Contact
Terminals 21 and 22 on 1TB close to indicate that a
system is running.
Alarm Contacts
The system has a single voltage-free contact, which
will operate to signal an alarm condition whenever any
system locks out, or there is a power failure. To obtain
the system alarm signal, connect the alarm circuit to
voltage-free Terminals 25 and 26.

SYSTEM INPUTS

The circuitry for the following system inputs is a
115VAC circuit. Contacts must be gold and rated for
low current (5mA). Connect the switches per instruc-
tions below. Refer to Table 20 on page 58 for the
terminal connections.
Chilled Liquid Flow Switch
Connect this switch between Terminals 2 and 13 of
1TB to provide protection against loss of liquid flow,
which will cause evaporator freeze-up, if the chiller is
permitted to run.
Condenser Liquid Flow Switch
This switch is expected across Terminals 2 and 12 of
1TB to indicate loss of liquid flow, which can result in
a rapid high head transient on the chiller.
Remote Run Permissive
A remote run permissive input is available and requires
a dry contact to start and stop. Remote dry contacts
are connected between Terminals 2 and 15 of 1TB. If
remote run permissive is not utilized, place a jumper
across the terminals to allow the system to run.
Remote Print
Closure of suitable contacts connected to Terminals 2
and 14 of 1TB will cause a hard copy of Operating
Data/Fault History to be printed, if an optional serial
printer is connected to the RS-232 port.
Optional Heat Pump Remote Mode Selection
A remote mode selection input is available when the
chiller is purchased with heat pump option. If the option
is enabled and remote mode selection is desired, connect
a switch across Terminals 10 and 41 of 1TB to switch
between chiller and heat pump operation remotely.
• Contacts Open = Chiller Mode
• Contacts Closed = Heat Pump Mode
58

TABLE 20 - SYSTEM INPUT CONNECTIONS

INPUT
Chilled Liquid Flow Switch
Condenser Liquid Flow Switch
Remote Run Permissive
Remote Print
Remote Heat Pump Mode
Optional Remote Setpoint Offset
The control panel provides for external input to reset:
• Compressor current limits
• Liquid temperature setpoints for Leaving Chilled
Liquid, and Heat Pump Leaving Condenser Liquid.

ANALOG INPUTS

The circuitry for the following analog inputs is for 10
VDC or 20mA current inputs when remote setpoint
control options are purchased and enabled.
Leaving Chilled Liquid Temperature Reset
Control
Install input for Leaving Chilled Liquid Temperature
Control remote reset across Terminals 17 (+) and 18 (-)
of the 1TB Terminal Block.
How To Receive Voltage Or Current Signal
The control board JUMPER JP4 must be positioned
correctly to receive a voltage (0-10 VDC or 2-10 VDC)
or a current (0-20 mA or 4-20 mA) signal. Place the
jumper in the V position for a voltage signal, or mA
for a current signal. Configure the software under the
OPTIONS key for the specific type of input signal to
be used.
The maximum temperature reset (100%) is achieved at
either 10 VDC or 20 mA. Sending the minimum sig-
nal (0 or 2 VDC, 0 or 4 mA, based on the OPTIONS
key) causes the setpoint to revert back to its local pro-
grammed value. If the setpoint reset causes the setpoint
to go over the maximum programmable value, it will
be set to the maximum programmable setpoint.
0-10 or 2-10 VDC Reset Input
A 0 or 2 VDC signal produces a 0°F (0°C) reset.
A 10 VDC signal produces a 100% (max.) reset
(SETPOINTS key). The setpoint reset is ramped lin-
early between these limits as the input varies between 0
or 2 VDC and 10 VDC. For this input to work properly,
the Remote Temperature Reset must be programmed
for 0–10 or 2-10 VDC input (OPTIONS key) and con-
trol board JUMPER JP4 placed in the V position.
FORM 201.30-ICOM1 (519)
ISSUE DATE: 05/22/2019
1TB TERMINALS
2 and 13
2 and 12
2 and 15
2 and 14
10 and 41
JOHNSON CONTROLS