Carrier 48LJD - Manual (Page 7)

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Step 5 — Install Flue Hood — Flue hood and screen
are shipped screwed to the burner compartment access panel.
Remove from shipping location and using screws provided,
install flue hood and screen in location shown in Fig. 7.
Step 6 — Install Gas Piping — Unit is equipped for
use with type of gas shown on nameplate. Refer to local
building codes, or in the absence of local codes, to ANSI
Z223.1-1984 and addendum Z223-1A-1987 entitled Na­
tional Fuel Gas Code. In Canada, installation must be in
accordance with the CANl.B 149.1 and CAN1.B149.2 in­
stallation codes for gas burning appliances.
For natural gas applications, gas pressure at unit gas con­
nection must not be less than 4 in. wg or greater than
13.0 in. wg while unit is operating. On 48LJ005,006,007
high heat units, the gas pressure at unit gas connection must
not be less than 5 in. wg or greater than 13 in. wg while the
unit is operating. For propane applications, the gas pressure
must not be less than 5 in. wg or greater than 13 in. wg at
the unit connection.
Size gas supply piping for 0.5 in. wg maximum pressure
drop. Do not use supply pipe smaller than unit gas connec­
tion. Support gas piping as shown in the table in Fig. 8. For
example, a %-in. gas pipe must have one field-fabricated
support beam every 8 ft. Therefore, an 18-ft long gas pipe
would have a minimum of 2 support beams, a 48-ft long
pipe would have a minimum of 6 support beams.
See Fig. 8 for typical pipe guide and locations of exter­
nal manual main shutoff valve.
9” MINIMUM CLEARANCE
FOR PANEL REMOVAL
MANUAL GAS GAS
I SHUTOFF VALVE* REGUUTOR*
48" MINIMUM -
DRIP LEG PER NFGC
ROOF CURB
7
FROM GAS METER
LEGEND
NFGC — National Fuel Gas Code
"Field supplied.
NOTE: Follow all local codes
FIELD-FABRICATED*
SUPPORT
SPACING OF SUPPORTS
STEEL PIPE
NOMINAL
DIAMETER
(In.)
X
DIMENSIONS
(feet)
% 6
*/4 or 1 8
1’/4 or larger 10
Step 7 — Make Electrical Connections
A WARNING
Unit cabinet must have an uninterrupted, unbroken elec­
trical ground to minimize the possibility of personal in­
jury if an electrical fault should occur. This ground may
consist of electrical wire connected to unit ground lug
in control compartment, or conduit approved for elec­
trical ground when installed in accordance with NEC
(National Electrical Code), ANSI/NFPA (National Fire
Protection Association), latest edition, and local elec­
trical codes. Do not use gas piping as an electrical ground.
Failure to follow this warning could result in the in­
staller being liable for personal injury of others.
Fig. 8 — Gas Piping Guide (With Accessory
Thru-the-Curb Service Connections)
FIELD POWER SUPPLY - All units except 208/230-v
units are factory wired for the voltage shown on the name­
plate. If the 208/230-v unit is to be connected to a 208-v
power supply, the transformer must be rewired by moving
the black wire from the 230-v orange wire on the trans­
former and connecting it to the 200-v red wire from
the transformer. The end of the orange wire must then be
insulated.
Refer to unit label diagram for additional information.
Wiring leads are provided for field service. Use copper con­
ductors only when splice connectors are used.
When installing units, provide a disconnect per NEC.
All field wiring must comply with NEC and local require­
ments. In Canada, electrical connections must be in accor­
dance with CSA (Canadian Standards Association) C22.1
Canadian Electrical Code Part 1.
Install conduit through side panel openings indicated in
Fig. 6. Route power lines through connector to terminal
connections as shown in Fig. 9.
Voltage to compressor terminals during operation must
be within voltage range indicated on unit nameplate (also
see Table 2). On 3-phase units, voltages between phases
must be balanced within 2% and the current within 10%.
Use the formula shown in the legend for Table 2, Note 2 to
determine the percent voltage imbalance. Operation on im­
proper line voltage or excessive phase imbalance consti­
tutes abuse and may cause damage to electrical components.
Such operation would invalidate any applicable Carrier
warranty.
FIELD CONTROL WIRING - Install a Carrier-approved
accessory thermostat assembly according to installation in­
structions included with the accessory. Locate thermostat
assembly on a solid wall in the conditioned space to sense
average temperature in accordance with thermostat instal­
lation instmctions. Connect thermostat wires to terminal board.
Route thermostat cable or equivalent single leads of col­
ored wire from subbase terminals through connector on unit
to low-voltage connections (shown in Fig. 10).
Connect thermostat wires to matching screw terminals of
low-voltage connection board. See Fig. 10.
NOTE; For wire runs up 50 ft, use no. 18 AWG (American
Wire Gage) insulated wire (35 C minimum). For 50 to
75 ft, use no. 16 AWG insulated wire (35 C minimum).
For over 75 ft, use no. 14 AWG insulated wire (35 C min­
imum). All wire larger than no. 18 AWG cannot be directly
connected to the thermostat and will require a junction box
and splice at the thermostat.
Pass the control wires through the hole provided in the
end panel; then feed wires through the raceway built into
the comer post to the 24-v barrier located on the left side of
the control box. See Fig. 11. The barrier provides the UL
(Underwriters’ Laboratories) required clearance between high-
and low-voltage wiring.