Pressure Test Gas Piping; High Altitude Derate; Electrical Connections - Lennox LGH180H Installation Instructions Manual

Pressure Test Gas Piping

When pressure testing gas lines, the gas valve must
be disconnected and isolated. Gas valves can be
damaged if subjected to more than 0.5 psig (3.48kPa).
See figure 6.
NOTE-Codes may require that manual main shut-off
valve and union (furnished by installer) be installed in
gas line external to unit. Union must be of the ground
joint type.
After all connections have been made, check all piping
connections for gas leaks. Also check existing unit gas
connections up to the gas valve; loosening may occur
during installation. Use a leak detection solution or other
preferred means. Do not use matches candles or other
sources of ignition to check for gas leaks.
NOTE-In case emergency shut down is required, turn off
the main manual shut-off valve and disconnect main
power to unit. These devices should be properly labeled
by the installer.
PRESSURE TEST GAS LINE
MANUAL MAIN
SHUT-OFF VALVE
GAS VALVE
FIGURE 6
CAUTION
Some soaps used for leak detection are corrosive
to certain metals. Carefully rinse piping thoroughly
after leak test has been completed. Do not use
matches, candles, flame or othe sources of ignition
to check for gas leaks.
WARNING
Danger of explosion. Can cause injury
or product or property damage. Do not
use matches, candles, flame or other
sources of ignition to check for leaks.
LGH/LCH156, 180, 210, 240, 300S

High Altitude Derate

Locate the high altitude conversion sticker in the unit
literature bag. Fill out the conversion sticker and affix next
to the unit nameplate.
Refer to table 1 for high altitude adjustments.
2000-4500
4500 And Above
*Units installed at 0-2000 feet do not need to be modified.
NOTE ‐ This is the only permissible derate for these units.

Electrical Connections

Route field wiring in conduit between bottom power entry
disconnect. See figure 7. This does not supersede local
codes or authorities having jurisdiction.
Do not apply power or close disconnect switch until
installation is complete. Refer to start-up directions.
Refer closely to unit wiring diagram.
Refer to unit nameplate for minimum circuit ampacity
and maximum fuse size.
1- Units are factory-wired for 240/460/575 volt supply.
CAP
2- Route power through the bottom power entry area
3- Units With Optional 120v GFCI Outlet -
4- Solar-Ready Units Only -
Page 10
TABLE 1
HIGH ALTITUDE DERATE
Altitude Ft.* Gas Manifold Pressure
See Unit Nameplate
Derate 2% / 1000 Ft. Above Sea Level
POWER SUPPLY
For 208V supply, remove the insulated terminal
cover from the 208V terminal on the control
transformer. Move the wire from the transformer
240V terminal to the 208V terminal. Place the
insulated terminal cover on the unused 240V
terminal.
and connect to line side of unit disconnect, circuit
breaker or terminal block. See unit wiring diagram.
Route and connect separate 120v wiring to GFCI
outlets which do not have factory-installed wiring.
Route field wiring in conduit between bottom power
entry and GFCI. See figure 7.
All solar-ready units are equipped with an S48
disconnect along with F54 and F56 fuse blocks
(located in the controls/compressor compartment).
Connect solar panel array wiring to the top of F54 and
F56 (one fuse block per solar array). Solar equipment
must be specified for use with this unit.