Sensaphone 400 - Manual (Page 109)

Chapter 8: Controlling the Output
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not be located near a window or where direct sunlight might warm it, near
a furnace radiator or vent, or any heat source such as a pilot light.
The second thermostat, the one pre-set for your preferred temperature
when you arrive at your cottage or cabin, should be located in your normal
living space. This would likely be your existing thermostat, already located
in a suitable location by your heating professional at the time your furnace
was installed.
By connecting these two thermostats together in a parallel fashion, and by
passing the low voltage supply through the Sensaphone (See Figure 1), you
can remotely or locally decide which thermostat is in control of your fur-
nace.
It is recommended that the “away” thermostat be connected to the NC
(Normally Closed) terminal while the “home” thermostat be connected to
the N0 (Normally Open) terminal of the Sensaphone. This way, it’s easy to
understand which state your furnace is in: Output ON = Home and Output
OFF = Away. The supply voltage from your furnace (typically the wire
labeled R or 24VAC), should always be connected to the C (Common) ter-
minal on the 400.
1 C
ZONES
2 C 3 C 4 C NO C NC
FURNACE
70º F
21º C
50º F
10º C
Home
Thermostat
Away
Thermostat
24 VAC
Transformer
Figure 1: Dual Thermostat Setup
Note: This is a typical configuration when using standard single-zone
heat/cool thermostats. For ease-of-use it is recommended that both
thermostats be the same model. Note also that all thermostats may not
be compatible with the dual-thermostat wiring diagram. Consult your
heating/cooling professional for installation assistance.