L.B. White Guardian Series, Owner'S Manual And Instructions, Page: 14 / 144

Guardian with Smart Sense™
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Owner’s Manual • Guardian
14
Interconnection for
Variable Heat
■ The Smart Sense™ variable rate heater incorpo-
rates a signal conditioner board in the control box.
This signal conditioner takes the control signal
supplied from the building controller and provides
the necessary power to control the variable rate
gas control valve.
■ When interconnecting the building controller to the
signal conditioner:
-- Use customer supplied 1/4 insulated female
terminals.
-- Use 18 gauge 2 conductor stranded shielded
cable for supply of DC volts or milliamp signal from
building controller to signal conditioner.
1. Open the heater’s control box for access to the
signal conditioner and wiring connections.
2. Route the wiring from the building controller
through the liquid tight connector adjacent to the
signal conditioner. see Fig. 7. Securely tighten the
connector after wiring has been connected to the
conditioner.
A. SIGNAL CONDITIONER SWITCH
SETTINGS
See Fig. 7
a. 0-10 mV DC signal,
- No setting is required.
b.4-20 mA or 0-20 mA signal,
- Set the selector switch accordingly.
Control signal wire connections are made at the screw
terminals. Observe polarity when making connections.
ATTENTION
In the event the building controller fails and providing
the heater has a backup thermostat, the signal condi-
tioner will boost the gas valve output to full heat. With
the heater operating in this condition the gas control
valve will not modulate.
FIG. 7
Building controller
control signal
connections (screw
terminal) mA or DCV
Output to
the gas
control
valve
24V
transformer
connection
Selector
Switch