Electrical - Lennox ML193UH Installation Instructions Manual

Electrical

WARNING
Electrostatic discharge can affect
electronic components. Take care
during unit installation and service to
protect the unit's electronic controls.
ELECTROSTATIC
Precautions will help to avoid control
DISCHARGE
exposure to electrostatic discharge
(ESD)
by putting the unit, the control and the
Precautions and
technician at the same electrostatic
Procedures
potential. Touch hand and all tools
on an unpainted unit surface before
performing any service procedure to
neutralize electrostatic charge.
WARNING
Electric Shock Hazard. Can cause
injury or death. Unit must be properly
grounded in accordance with national
and local codes.
WARNING
Fire Hazard. Use of aluminum wire with this product may
result in a fire, causing property damage, severe injury
or death. Use copper wire only with this product.
INTERIOR MAKE-UP BOX INSTALLATION
MAKE-UP
BOX
FIGURE 57
The unit is equipped with a field make-up box. The make-
up box may be moved to the right side of the furnace to
facilitate installation. Seal unused openings on left side
with plugs removed from right side. Secure the excess
wire to the existing harness to protect it from damage.
Refer to FIGURE 58 for schematic wiring diagram and
troubleshooting.
The power supply wiring must meet Class I restrictions.
Protected by either a fuse or circuit breaker, select circuit
protection and wire size according to unit nameplate.
Failure to use properly sized wiring and circuit breaker
may result in property damage. Size wiring and circuit
breaker(s) per Product Specifications bulletin (EHB) and
unit rating plate.
NOTE - Unit nameplate states maximum current draw.
Maximum Over-Current Protection allowed is 15 AMP.
Holes are on both sides of the furnace cabinet to facilitate
wiring.
Install a separate (properly sized) disconnect switch near
the furnace so that power can be turned off for servicing.
Before connecting the thermostat check to make sure
the wires will be long enough for servicing at a later date.
Make sure that thermostat wire is long enough to facilitate
future removal of blower for service.
Complete the wiring connections to the equipment. Use
the provided unit wiring diagram and the field wiring shown
in FIGURE 58. Use 18-gauge wire or larger that is suitable
for Class II rating for thermostat connections.
Electrically ground the unit according to local codes or,
in the absence of local codes, according to the current
National Electric Code (ANSI/NFPA No. 70) for the USA
and current Canadian Electric Code part 1 (CSA standard
C22.1) for Canada. A green ground wire is provided in the
field make-up box.
NOTE - The ML193UH furnace contains electronic com-
ponents that are polarity sensitive. Make sure that the fur-
Right Side
nace is wired correctly and is properly grounded.
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CAUTION