Outdoor Air Sensor (Oas); Wiring Specifications; Reducing Electrical Noise On Communication Bus - Lennox iComfort E30 Installation And Setup Manual

o a s (oas)
utDoor ir Ensor
The optional outdoor air (temperature) sensor (OAS) (X2658) wiring distance to
either the furnace or air handler control should not exceed 200 feet (61 meters)
when wired with 18 #AWG thermostat wire. Installation of OAS must comply with
the following requirements:
• Sensor wiring must be run to avoid touching or being close to high voltage wiring
and light ballast.
• Choose a protected outdoor location away from direct sunlight or other heat
sources (usually on the north side of the building).
• Ensure that water will neither collect on, or wash over the sensor.
• Do not locate the sensor near driveways or similar heat-absorbing masses which
may reflect stored heat energy onto the sensor and send inaccurate information
to the thermostat.
• Locate the sensor away from attic and soffit vents, or furnace venting pipes.
• Do not locate the sensor directly above an air conditioner or heat pump.
W s
iring pECiFiCations
The following is the wiring specification for the system:
• Smart Hub to Mag-Mount wiring size is 18 #AWG.
• Thermostat does not required shielded cable wiring.
• Maximum total length of all connections combined is 1500 feet (457 meters).
• Maximum length between components is 300 feet (90 meters).
r E n C
EDuCing lECtriCal oisE on ommuniCation
Communicating systems requires four thermostat wires between the Mag-Mount
and Smart Hub. Four wires are also used between the Smart Hub and indoor/
outdoor units as well.
When a thermostat cable with more than four wires is used, the extra wires
must be properly connected to avoid electrical noise. The wires must not be left
disconnected.
• Use wire nuts to bundle the unused wires at each end of the cable. A single
wire should then be connected to the indoor unit end of the wire bundle and
attached to the "C" terminals as shown in "Figure 4. Thermostat Wire Termination
in Communicating Systems (Electrical Noise)".
• Keep all communication wiring as far away from the house electrical wiring and
large electrical appliances as possible. Recommended minimal distance is 15
feet (5 meters).
•
B
us
0 1 2 3
UNIT HEAT
TYPE STAGES
W1 W2 W3 G Y2 Y1 C DS R H O B
E30 SMART HUB
Figure 6. Smart Hub to Mag-Mount
11
MAG-MOUNT
12VDC COMM BUS
+ - A B
ACC1 ACC2
12VDC
+ -
Terminal C
Unused
wires
Single wire from bundle
to Smart Hub 24VAC
COMM BUS
A B