Wiring Dry Contact Devices To Display Alerts; Connecting A Stage Of Heating Or Cooling To A Universal Relay (U1, U2, U3) - Honeywell Prestige IAQ YTHX9421 Installation Manual

Conventional System
Terminal
Universal relay for humidification,
U1 / U1** dehumidification, ventilation, or
U2 / U2** a stage of heating/cooling. U
U3 / U3** terminals are dry contacts that
require power.
Universal input for a wired indoor
S1 / S1***
sensor, outdoor sensor, discharge
S2 / S2***
sensor, return sensor, dry contact
S3 / S3***
device for alerts or dry contact
S4 / S4***
device for remote setback.
A
Connect to THM4000R1000
B
Wireless Adapter for extended
C
wireless range.
D
** See wiring diagrams on pages 4-5.
*** See wiring diagram below for wiring Dry Contact Devices to display alerts.

Wiring dry contact devices to display alerts

DISCONNECT POWER BEFORE INSTALLATION.
Do not apply power to S1, S2, S3 or S4 terminals.
NOTE:
The dry contact device must
be rated for low voltage.
Connect a dry contact device such as a
water sensor to S1, S2, S3 or S4 terminals.
The thermostat displays an alert when a
problem is detected.
Connecting a stage of heating or cooling to a universal relay
(U1, U2, U3)
1
U1, U2, and U3 are normally
open dry contacts when set up
for a stage of heating or cooling.
2 You must install a field jumper if
the stage of heating or cooling is
powered by the system trans-
former. Do NOT install a field
jumper if the stage of heating has
its own transformer.
Terminal Designations
Description Terminal
Universal relay for humidification,
U1 / U1** dehumidification, ventilation, or
U2 / U2** a stage of heating/cooling. U
U3 / U3** terminals are dry contacts that
require power.
Universal input for a wired indoor
S1 / S1***
sensor, outdoor sensor, discharge
S2 / S2***
sensor, return sensor, dry contact
S3 / S3***
device for alerts or dry contact
S4 / S4***
device for remote setback.
A
Connect to THM4000R1000
B
Wireless Adapter for extended
C
wireless range.
D
EIM
U3
U3
U2
HEAT STAGE 3,
U2
COOL STAGE 3,
COOL STAGE 4 OR
U1
GEOTHERMAL
1
RADIANT HEAT
U1
2
RH
RC
R
24
VAC
C
4
Heat Pump
Description
ONE DRY CONTACT DEVICE
MULTIPLE DRY CONTACT DEVICES
ON ONE SET OF TERMINALS
TRANSFORMER
24
VAC
120
VAC