Electrical Connections - Lennox LF24-100 Installation Instructions Manual

Electrical Connections

NOTE − Local codes may supersede any of the provisions
outlined in this instruction.
The LF24 series unit heaters use a direct spark ignition
system. There is no pilot necessary as the spark lights the
main burner as the gas valve is turned on. The direct
spark ignition control board emits radio noise as the
sparking process is under way. The level of energy may
be sufficient to disturb a logic circuit in a microprocessor
controlled thermostat. It is recommended that an isolation
relay be used when connecting the LF24 series unit
heaters to a microprocessor−controlled thermostat. Install
the thermostat according to instructions provided by the
manufacturer. Install a separate fused disconnect switch,
with the fuse sized according to blower motor size.
Connect wiring through knockout on the junction box
located on the side of the unit heater. Refer to heater
wiring diagram for connection information. Use 18 gauge
wire or larger for thermostat connections.
NOTE − Electrically ground unit in accordance with local
codes or, in the absence of local codes, in accordance
with the current National Electrical Code (ANSI/NFPA No.
70) in the U.S.A., and in Canada with the current
Canadian Electrical Code, Part 1 (CSA C22.1).
NOTE − Uninsulated ground wires must be wrapped in
electrical tape to avoid damage to the electrical system.
Connect field wiring as shown on wiring diagram on unit.
Also refer to typical diagram in this manual. An additional
thermostat wire must be run to terminal G" on heater
when continuous blower is desired.
TYPICAL LF24 WIRING SCHEMATIC
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