Installation guide

ACCESSORY INSTALLATION
a. ACCESSORY ELECTRIC HEATERS
Electric heaters may be installed with the 50XZ units
per instructions supplied with electric heater package.
See unit rating plate for factory-approved electric heater
kits.
b. AUXILIARY TERMINALS
The AUX and HUM terminals on the Easy Select Board
are tied directly to the G terminal, and provide a 24-v.
signal whenever the G terminal is energized (See Fig.
19). During Super dehumidify mode, the G signal is not
present and the auxiliary terminals are not energized. If
the installation includes the use of the operating mode,
do not use these terminals to control accessories. See
Electronic Air Cleaner and Humidifier sections for
further information.
c. ELECTRONIC AIR CLEANER CONNECTIONS
The AUX1 and AUX2 terminals are not always
energized during blower operations, as described above.
When using an electronic air cleaner with the unit, use
Airflow Sensor (See Air Cleaner Price Pages for Part
Number). The airflow sensor turns on electronic air
cleaner when the blower is operating.
d. HUMIDIFIER/HUMIDISTAT CONNECTIONS
Easy Select '_ Board terminals HUMI and HUM2 are
provided for direct connection to the low-voltage
control of a humidifier through a standard humidistat
(See Fig. 19-21). These terminals are energized with
24-v. when G thermostat signal is present. (See Fig.
19-21). Alternately, the 24-v. signal may be sourced
from the W and C circuit board connections. When
using a Thermidistat '_ Control, Zone Comfort Plus or
Comfort Zone II, the 24-v. signal may be sourced
directly from the Thermidistat '_ HUM terminal.
HUMIDISTAT
HUM 1F]
(c)
HUM 2F]
(G)
24-VAC TO HUMIDIFIER
J
HUMIDIFIER WIRING
Fig. 20 - Humidifier Wiring for 50XZ
EASY SELECT[q
BOARD TERMINAL[q
BLOCK
Ag5317
J1
REMOVEJ ''_]
JUMPER
1
I
HUMIDISTAT
I
.I
Fig. 21 -
e,
Ag5316
Humidistat Wiring for De-Humidify Mode for 50XZ
DEHUMIDIFY CAPABILITY WITH STANDARD
HUMIDISTAT CONNECTION
Latent capacities for these units are better than average
systems. If increased latent capacity is an application
requirement, the circuit board provides connection
terminals for use of a standard humidistat. The unit will
detect the humidistat contacts opening on increasing
humidity and reduce its airflow to approximately 80
percent of nominal cooling mode airflow. This reduction
will increase the system latent capacity until the
humidity falls to a level which causes the humidistat to
close its contacts. When the contacts close, the airflow
will return to 100 percent of selected cooling airflow. To
activate this mode, remove jumper J1 and wire in a
standard humidistat (See Fig. 19-21).
f. DEHUMIDIFY AND SUPER DEHUMIDIFY
CAPABILITIES
These models are capable of responding to a signal from
indoor system control (thermostat, Thermidistat, zoning
control) to operate in comfort control modes such as
Super Dehumidify Mode. Consult literature provided
with indoor system control to determine if these
operating modes are available, and to see control set up
instructions. No special setup or wiring of unit is
required.
50XZ SEQUENCE OF OPERATION
a. CONTINUOUS FAN
(1.) Thermostat closes circuit R to G-The Blower runs
at continuous fan airflow.
b. COOLING MODE-LOW HUMIDITY
(1.) If indoor temperature is above temperature set
point and humidity is below humidity set point,
thermostat closes circuits R to G, R to Y/Y2 and R
to O-The unit delivers cooling airflow.
c. COOLING MODE-DEHUMIDIFICATION
(1.) If indoor temperature is above temperature set
point and humidity is above humidity set point,
thermostat or Thermidistat closes circuits R to G, R
to O, and R to Y/Y2 and humidistat or
Thermidistat opens R to DH-The unit delivers
airflow which is approximately 80 percent of the
nominal cooling airflow to increase the latent
capacity of the system.
d. COOLING MODE-SUPER DEHUMIDIFY
OPERATION (see quick reference guide)
NOTE: The indoor control used, such as a Thermidistat, nmst be
capable of providing Super Dehumidify operation mode and
control must be configured as outlined in its installation
instructions. Consult indoor control literature to determine if
control is capable of providing Super Dehumidify inputs and for
configuration instruction.
(1.) If the indoor temperature is below the temperature
set point and the humidity is above the humidity
set point, the Thermidistat closes circuit R to O,
opens circuits R to DH and R to G, and cycles
circuit R to Y/Y2. If circuit R to G is closed
(24-v.), the motor will deliver airflow at the full
cooling or cooling plus dehumidify mode
requested value. If circuit R to G is open (0-v.) for
super dehumidify mode, the motor delivers
reduced airflow to maximize the humidity removal
of the system while minimizing over cooling.
e. ELECTRIC HEATING MODE
(1.) Thermostat closes circuit R to W/W1, or W2-The
unit delivers the selected electric heat airflow. There are
no on or off delays.
f. HEAT PUMP HEATING MODE
(1.) Thermostat closes circuits R to G and R to
Y/Y2-The unit delivers selected heat pump heating
airflow.
g. HEAT PUMP HEATING WITH AUXILIARY
ELECTRIC HEAT
(1.) Thermostat closes circuits R to G, R to Y/Y2 and
R to W/WI or W2 (and R to O in the case of
defrost).
In the event that electric heating is called for by the
thermostat while the heat pump is also operating in
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