Leviton omnistat 3 Directives D'installation page 20

4-Pipe - Continued
7. Test the "Heat" mode by performing the following steps:
a. Tap the "-" or "+" button one time – this will bring up the raise/lower setpoint, as
well as a " flame" or "snowflake" icon below the setpoint.
b. Tap the Fan button as necessary, to change the icon below the setpoint to " flame"
(Heat mode).
c. Use the "+" button to raise the desired heat setpoint above the current temperature
(recommend 2 degree raise). Ensure that the heating unit comes on.
d. Use the "-" button to lower the heat setpoint back below the current temperature.
Ensure that the heating unit goes off.
8. Test the "Cool" mode by performing the following steps:
a. Tap the "-" or "+" button one time – this will bring up the raise/lower setpoint, as
well as a " flame" or "snowflake" icon below the setpoint.
b. Tap the Fan button as necessary, to change the icon below the setpoint to
"snowflake" (Cool mode).
c. Use the "-" button to lower the desired cool setpoint below the current temperature
(recommend 2 degree decrease). Ensure that the cooling unit comes on.
d. Use the "+" button to raise the cool setpoint back above the current temperature.
Ensure that the cooling unit goes off.
Pipe Temperature Sensor
An external pipe temperature sensor can be installed to monitor the temperature of the
pipe in a 2-pipe system. The thermostat uses the temperature from the external pipe
temperature sensor to determine if the thermostat will be calling for cooling or heating.
The temperature sensor should be a point-matched 10,000 ohms @ 25°C thermistor,
R/T Curve A, ±5% @ 25°C.
Run a twisted pair, shielded cable from the RC500-2EW to the pipe where the external
pipe temperature will be installed. For distances up to 100 feet, typical twisted pair,
PVC-insulated, shielded cable may be used. For distances from 100-150 feet, twisted
pair with polypropylene insulated conductors, shielded must be used. For distances
from 150-250 feet, twisted pair with foam-polyethylene insulated conductors, shielded
must be used. Wire runs must not exceed 250 feet.
Crimp each wire of the cable to crimp terminals (Harwin Inc. P/N: M20-1180046, or
equivalent) and insert the terminals into a two-pin SIL connector (Harwin Inc. P/N
M20-1060200, or equivalent). Insert the assembled two-pin SIL connector into the
two-position header terminal labeled J4 on the back of the thermostat printed circuit
board - See Figure 12.
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