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SSCBL-RPBL-IOM (10-22) 149159-C
INSTALLATION—CONTINUED
Electrical Connections—Continued
Control Wiring—Continued
⚠ CAUTION ⚠
Ensure that the thermostat has an adequate VA rating for the total requirements. Add the coil rating
of all relays and match the thermostat rating.
NOTE: If the low-voltage thermostat is equipped with a heat anticipator, set the anticipator at full
load control amps.
• Thermostat:
A 24V thermostat must be used to actuate low voltage gas controls . If line voltage from the thermostat
to the unit is desired, consult the factory representative . Thermostats should be located 5 feet (1 .5 meters) above
the floor on an inside wall, not in the path of warm or cold air currents and not in corners where air may be pocketed .
Do NOT install on cold air walls . For specific connection details, refer to instruction packet with the thermostat .
If more than one furnace is cycled from one thermostat, separately activated relays must be substituted at unit
thermostat connections .
• Remote console:
If the unit being installed includes an optional remote console, it is shipped separately for field
installation . All consoles include indicator lights for the blower and burner . Consoles may include a dirty filter
indicator light, a cooling indicator light, an ON/OFF switch, a summer/off/winter switch, a heat/vent/cool switch, a
potentiometer, a thermostat, and/or a Maxitrol temperature selector . Consoles are shipped separately for remote
installation and may be either mounted on a wall or recessed .
• Maxitrol system:
Control wires connected to a Selectrastat, a discharge air sensor, a remote temperature selector
or sensor, an amplifier, or the valve must not be run close to or inside conduit with power or ignition wires . Doing
so may cause the unit to function erratically or may destroy the amplifier . If shielded wires are used, shield must
be insulated and grounded at the amplifier location only .
• Pressure null switch:
a . Select indoor location free from excessive vibration where oil or water will not drip onto switch and where
ambient temperature is
−
30°F (dry air) to 110°F .
b . Mount switch with diaphragm in vertical plane . Switch is position-sensitive and is calibrated to operate properly
when diaphragm is vertical . Mount switch securely .
c . Connect pressure taps on top of switch to sources of air pressure differential . Metal tubing with 1/4-inch OD is
recommended, but any tubing system that does not unduly restrict air flow may be used . To maintain positive
building pressure, vent low pressure tap to outdoors and allow high pressure tap to monitor building pressure .
To maintain negative building pressure, reverse functions of high and low pressure taps . In either case, ensure
that outdoor vent is protected from wind and is screened from insects .
d . Adjustment of switch: HIGH actuation point of switch is indicated on calibrated scale secured to transparent
range screw enclosure . Building pressure is set by turning adjustment screw . LOW actuation point is set by
adjusting span of null by turning span adjustment screw . Span range is 0 .01 to 0 .03 IN WC .
e . Refer to wiring diagram provided with unit to make electrical connections .
