Carrier WeatherExpert 48LC Series - Economizer Setup and Configuration

38
Fig. 50 — HACR Caution Label
FACTORY-OPTION THRU-BASE CONNECTIONS
All units are equipped with the ability to bring utilities through the
base.
Gas is brought up through an embossed area located in the gas
section behind the gas entrance post. Access is gained through the
gas access panel. A knock out must be removed to accomplish
this.
The electrical entrance is located in the control box area and can
be accessed through the control box access panel. An embossed
area is provided with three knock outs. High voltage is brought
through the multi knock out by removing the appropriate size for
the size of the fitting required. A
7
/
8
-in. knock out is provided for
low voltage. An additional
7
/
8
-in. knock out is provided for a 115 v
line which is used when the unit is equipped with the non-unit
powered convenience outlet option.
All required fittings are field supplied. Install fittings when access
to both top and bottom of the base pan is available. See electrical
and gas connections for routing and connection information.
UNITS WITHOUT THRU-BASE CONNECTIONS
1. Install liquid tight conduit between disconnect and control
box.
2. Pull correctly rated high voltage wires through the conduit.
3. Install power lines to terminal connections as shown in
Fig. 45.
FIELD CONTROL WIRING
The 48LC unit requires an external temperature control device
such as a thermostat (field-supplied).
THERMOSTAT
Install a Carrier-approved accessory 3-stage thermostat according
to installation instructions included with the accessory. If a 3-stage
cooling thermostat is not available use a 2-stage cooling thermo-
stat 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 ther-
mostat installation instructions.
If the thermostat contains a logic circuit requiring 24-v power, use
a thermostat cable or equivalent single leads of different colors
with minimum of eight leads. If the thermostat does not require a
24-v source (no “C” connection required), use a thermostat cable
or equivalent with minimum of seven leads. Check the thermostat
installation instructions for additional features which might re-
quire additional conductors in the cable.
For wire runs up to 50 ft (15 m), use no. 18 AWG (American Wire
Gage) insulated wire (95°F [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 (95°F [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.
UNIT WITHOUT THRU-BASE CONNECTION KIT
Correctly rated low voltage wire can be routed through the rubber
grommet located on the corner post adjacent to the control box ac-
cess panel. Route wire through the grommet and then route the
wire behind the corner post utilizing the factory provided wire ties
secured to the control box. This will ensure separation of the field
low voltage wire and the high voltage circuit. Route the low volt-
age wire to the Integrated Staging Control (ISC) board. See
Fig. 51.
NOTE: If utilizing the through the base connections, route the low
voltage wire through the wire ties to the Integrated Staging Con-
trol (ISC) board (see Fig. 52).
Fig. 51 — Typical Low-Voltage Control Connections
C
G
C
G
O/B/Y2
Y2
R
R
Y1
Y1
Y3
Y3
(Note 1)
(Notes 2, 3 & 4)
(Note 3 & 4)
W1
W1
W2
W2
T
H
E
R
M
O
S
T
A
T
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
Integrated Staging Control
(ISC) Board or
SystemVu
TM
Controller
Typical
Thermostat
Connections