Field Control Wiring; Unit Without Thru-Base Connection Kit; Humidi-Mizer System - Space Rh Controller - Carrier WeatherExpert 48LC Series Installation Instructions Manual

UNITS WITHOUT THRU-BASE CONNECTIONS
1. Install power wiring conduit through side panel openings.
Install conduit between disconnect and control box.
2. Install power lines to terminal connections as shown
in Fig. 39.

FIELD CONTROL WIRING

The 48LC unit requires an external temperature control device
such as a thermostat (field-supplied).
THERMOSTAT
Install a Carrier-approved accessory thermostat according to in-
stallation instructions included with the accessory. For complete
economizer function and 3-stage compressor operation select a
three-stage cooling thermostat. If a 3-stage cooling thermostat is
not available, use a 2-stage cooling thermostat instead, but note
that this will limit cooling to just 2 stages. Locate the thermostat
accessory on a solid wall in the conditioned space to sense average
temperature in accordance with the thermostat installation instruc-
tions.
If the thermostat contains a logic circuit requiring 24-v power,
use a thermostat cable or equivalent single leads of different col-
ors with minimum of eight leads. If the thermostat does not re-
quire a 24-v source (no "C" connection required), use a thermo-
stat cable or equivalent with minimum of seven leads. Check the
thermostat installation instructions for additional features which
might require additional conductors in the cable. See Fig. 51.
For wire runs up to 50 ft (15 m), use no. 18 AWG (American Wire
Gage) insulated wire (35°C minimum). For 50 to 75 ft (15 to
23 m), use no. 16 AWG insulated wire (35°C minimum). For over
75 ft (23 m), use no. 14 AWG insulated wire (35°C minimum). All
wire sizes larger than no. 18 AWG cannot be directly connected to
the thermostat and will require a junction box and splice at the
thermostat.
Typical
Thermostat
Connections
C
W1
W2
G
Y3
(Note 3 & 4)
O/B/Y2
(Notes 2, 3 & 4)
(Note 1)
Y1
R
Note 1: Typical multi-function marking. Follow manufacturer's configuration
Instructions to select Y2.
Note 2: Y2 to Y3 connection required for 2-stage cooling operation and when
integrated economizer function is desired.
Note 3: To Connect a 2-Stage Thermostat:
Y2 to Y3 connection required for 2-stage cooling operation which
provides low and high cooling states.
Note 4: SystemVu controller is default configured for 3-stage cooling and
2-stage heating thermostats; it can be configured for other thermostat types.
Field Wiring
Fig. 51 — Typical Low-Voltage Control Connections
Integrated Staging Control
(ISC) Board or
TM
SystemVu Controller
C
W1
T
H
W2
E
R
G
M
O
Y3
S
T
Y2
A
T
Y1
R

UNIT WITHOUT THRU-BASE CONNECTION KIT

Pass the thermostat control wires through the bushing on the unit
end panel. Route the wire through the snap-in wire tie and up to
the web bushing near the control box. Route the wire through the
bushing and into the bottom left side of the control box after re-
moving one of the two knockouts in the corner of the box. Using a
connector at the control box to protect the wire as it passes into the
control box pull the wires over to the terminal strip at the lower
left corner of the Integrated Staging Control (ISC) Board. Use the
connector at the control box and the wire tie to take up any slack in
the thermostat wire to ensure that it will not be damaged by con-
tact with the condenser coil. See Fig. 52.
Fig. 52 — Thermostat Wire Routing
NOTE: If thru-the-bottom connections accessory is used, refer to
the accessory installation instructions for information on routing
power and control wiring.
HEAT ANTICIPATOR SETTINGS
Set heat anticipator settings at 0.14 amp for the first stage and 0.14
amp for second-stage heating, when available.
Humidi-MiZer System Control Connections
®
NOTE: It is suggested to ensure the Auto-Changeover function of
an installed thermostat is enabled when used in conjunction with
the Humidi-MiZer Adaptive Dehumidification system.
HUMIDI-MIZER SYSTEM – SPACE RH CONTROLLER
The Humidi-MiZer dehumidification system requires a field-sup-
plied and installed space relative humidity control device. This de-
vice may be a separate humidistat control (contact closes on rise in
space RH above control setpoint) or a combination thermostat-hu-
midistat control device with isolated contact set for dehumidifica-
tion control. See Fig. 53.
NOTE: Use of a humidistat device is not permitted on 48LC units
equipped with RTU Open control; these units require use of a
field-supplied RH sensor (33ZCSENSRH-02 or 33ZHCSEN-
DRH-02), or a ZS series sensor with humidity sensing. System-
Vu™ controls requires a Space Humidistat (HL38MG029), a Wall
Mount Space Humidity Sensor (33ZCSENSRH-01), or a Duct
Mount Humidity Sensor (33ZCSENDRH-01).
To connect the Carrier humidistat (HL38MG029)
1. Route the humidistat 2-conductor cable (field-supplied)
through the bushing in the unit's louvered end panel (see
Fig. 52).
2. Route the cable through the snap-in wire tie and up to the
web bushing near the control box.
3. Feed the cable through the bushing and into the bottom
left side of the control box after removing one of the two
knockouts in the corner of the box. Use a connector to pro-
tect the cable as it enters the control box.
30
Thermostat Wire