240005126 Rev A 10/27/2005
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air supplied to the burner. The control should also be
located near the furnace flue outlet and installed
according to the instructions supplied with the
regulator. The flue outlet pressure (measured between
the furnace and draft regulator) should be set to -0.02
in. w.c.
9. OPTIONAL SIDE WALL VENTING
These furnaces are also approved for use with the
Field Controls Co. SWG II-5 power venter. For
installation instructions refer to the manual supplied
with the venter, and the control package supplied with
the power venter. The power venter may be purchased
at most HVAC supply houses.
Note: Sidewall venting requires special attention to
combustion air supply. There is no natural draft in the
venting system between furnace cycles; therefore, if
the indoor pressure is negative relative to the
outdoors, the vent terminal becomes a point of
infiltration. This could lead to oil odour control
problems. This problem is rectified by the use of
ducted outdoor air for combustion.
10. FAN / LIMIT CONTROL
The L6064A temperature sensitive fan switch is
actuated by a helical bimetal sensing element
enclosed in a metal guard and controls the circulating
air blower. This provides a delay between the burner
ignition and blower start up to eliminate excessive flow
of cold air when the blower comes on. Blower
shutdown is also delayed to remove and residual heat
from the heat exchanger and improve the annual
efficiency of the furnace. Fan settings of 120º F to 130º
F (50º C to 55º C) and fan settings of 90º F to 100º F
(32º C to 37ºC) will usually be satisfactory. The fan
switching function of the L6064A is SPDT.
The limit switch performs a safety function and
operates to shut off the burner in case of overheating
or excessive temperatures. The limit control is
thermally operated and automatically resets. The limit
control is factory pre-set, and should not be adjusted.
The limit control and fan control are incorporated in the
same housing and are operated by the same thermal
element.
11. ELECTRICAL CONNECTIONS
The furnace is listed by the Canadian Standards
Association under the NRTL (North American)
Standard. It is factory wired and requires minimal field
wiring. All field wiring should conform to CAN/CSA
C22.1 Canadian Electrical Code, Part 1, and by local
codes, where they prevail. In the United States, the
wiring must be in accordance with the National Fire
Protection Association NFPA-70, National Electrical
Code, and with local codes and regulations.
The furnace should be wired to a separate and
dedicated circuit in the main electrical panel; however,
accessory equipment such as electronic air cleaners
and humidifiers may be included on the furnace circuit.
Although a suitably located circuit breaker can be used
as a service switch, a separate service switch is
advisable. The service switch is necessary if reaching
the circuit breaker involves becoming close to the
furnace, or if the furnace is located between the circuit
breaker and the means of entry to the furnace room.
The furnace switch (service switch) should be clearly
marked, installed in an easily accessible area between
the furnace and furnace room entry, and be located in
such a manner to reduce the likelihood that it would be
mistaken as a light switch or similar device.
The power requirement for the HTL-C models is: 120
VAC, single phase, 60 Hz., 12A. Power requirement
for the HTL-CT models is: 120 VAC, single phase, 60
Hz., 16A.
Accessories requiring 120 VAC power sources such as
electronic air cleaners and humidifier transformers may
be powered from the furnace circuit, but should have
their own controls. Do not use the direct drive motor
connections as a power source, since there is a high
risk of damaging the accessories by exposure to high
voltage from the auto-generating windings of the direct
drive motor.
Thermostat wiring connections and air conditioning
contactor low voltage connections are shown in the
wiring diagrams in Appendix B. Some micro-electronic
thermostats require additional controls and wiring.
Refer to the thermostat manufacturer's instructions.
The thermostat should be located approximately 5 feet
above the floor, on an inside wall where there is good
natural air circulation, and where the thermostat will be
exposed to average room temperatures. Avoid
locations where the thermostat will be exposed to cold
drafts, heat from nearby lamps and appliances,
exposure to sunlight, heat from inside wall stacks, etc.
The thermostat heat anticipator should be adjusted to
the amperage draw of the heating control circuit as
measured at the "R" and "W" terminals of the
thermostat. To reduce the risk of damaging the heat
anticipator, do not measure this current with the
thermostat connected to the circuit. Measure the
amperage by connecting an ammeter between the two
wires that will connect to the thermostat "R" and "W"
terminals.
12. HUMIDIFIER
A humidifier is an optional accessory available through
most heating supplies outlets. Installation should be
carried out in accordance with the humidifier
manufacturer's installation instructions. Water or water
droplets from the humidifier should not be allowed to
come into contact with the furnace heat exchanger. Do
