Wiring The Outdoor Sensor; Wiring The Boiler Return Sensor; Wiring The Slab Supply And Return Sensors - heat-timer SMC Installation & Operation Manuals

WIRING ThE OUTDOOR SENSOR

(Used when System Startup Sensor Type is set to Outdoor)
Terminals (16) and (17)
• The Outdoor Sensor is used only when it is difficult to use a Slab
Sensor. See "Outdoor Sensor Installation" on page 11.
• You can extend the sensor wires up to 500' by splicing it with
2-conductor 18AWG shielded cable (Belden #8760 or equivalent).
• Temperature sensor wires have no polarity. Connect the sensor wires
to the SMC's terminal 16 (Slab Temp/Out/Brown) and terminal 17
(Sensor Com/ Blue).
• Connect the shield to terminal 17 with one of the sensor wires. Do
not connect the shield at the sensor.

WIRING ThE BOILER RETURN SENSOR

(Available in Motorized Valve Control Mode Only)
Terminals (30) and (31)
• The use of the Boiler Return to help protect the boiler from
condensation and thermal shock is optional. A Heat-Timer
temperature sensor (HT #904250-00 or HT# 904220-00) immersed in
a 3/8 ID well (HT# 904011-00) is required. Both the sensor and well
must be purchased separately. See "Boiler Return Sensor" on page 11.
• If the Boiler Return Sensor is connected, the SMC will display its
temperature during melting and below the ISP temperature.
• If the Boiler Return Sensor value was below the Minimum Return,
the SMC will modulate the motorized valve to increase the return
temperature.
• The sensor wires can be extended up to 500' using 2-conductor
18AWG shielded cable (Belden #8760 or equivalent ).
• Temperature sensors have no polarity. Connect the sensor wires to
the SMC's terminals 30 and 31.
• Connect the shield to the circled terminal 31 with one of the sensor
wires. Do not connect the shield at the sensor.

WIRING ThE SLAB SUPPLy AND RETURN SENSORS

Slab Supply Terminals (26 )and (27)
Slab Return Terminals (28) and (29)
• The SMC is designed to use the Slab Supply and Slab Return
Temperature Sensors to calculate the energy put into the slab.
• Each sensor must be immersed in a 3/8 ID well (HT #904011-00).
Both Sensors and their wells are supplied with the SMC.
• You can extend the sensor wires up to 500' by splicing it with
2-conductor 18AWG shielded cable (Belden #8760 or equivalent).
• Connect the Slab Supply sensor wires to the SMC 26 and 27
terminals.
• Connect the shield to the circled terminal 27 with one of the sensor
wires. Do not connect it to the sensor.
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SMC Installation and Operation Manual
16 17 18 19 20 21
SLAB SLAB BOILER
SHUTDOWN
SUPPLY RETURN RETURN
PROVE
/ENABLE
TEMP TEMP TEMP
26 27 28 29 30 31 32 33 34 35