L.B. White AW250(Smart Box controller) - Manual (Page 5)

Basic Operation
FANS
ENVIRONMENT
CONTROLLER L.B. WHITE
Smart Box
™
ENABLE
CONTROL SIGNAL
TO GAS VALVE
115 VAC TO HEATER
115 VAC
INCOMING
POWER
SmartBox™ SENSORS
EXISTING ROOM
SENSORS
GUARDIAN
HEATER(S) WITH
Smart Sense ™
GUARDIAN WITH Smart Sense
™
This heater uses Smart Sense
™
technology for variable
rate heat control. When integrated to a building controller
and L.B.White SmartBox
™,
precise, automated control of the
environment is achieved by operating the heater over a
broad heat range from 65,000 btu to 250,000 btu. This
provides better, more even temperature distribution by
allowing the heater to operate where it needs to. This results
in consistent temperatures and reduced fuel consumption.
As shipped from the factory, the heater is wired to start
and operate at minimum heat. Connection to an
L . B . W h i t e SmartBox™ a n d b u i l d i n g e n v i r o n m e n t
controller is required for further operation. See Fig.1 for
a typical system diagram.
Each SmartBox
™
controls two zones of heat, two heaters
per zone .
One sensor may be used for each zone of heat, however
two sensors are normally used for optimum temperature
management..
Sequence of Operation
a. 115 VAC is supplied to SmartBox™.
b. Call for heat occurs from building controller.
c. Building controller closes heating contacts, and
energizes the SmartBox™.
d. SmartBox™ sends 115 VAC to heater and
simultaneously sends anywhere from 1-15 VDC to
Smart Sense ™ variable rate gas control valve.
-- Variable rate valve opens at specific firing rate
to meet temperature demands
e. Ignition of gas occurs.
-- Room warms to desired temperature.
f. Building controller recognizes desired temperature has
been achieved.
g. Building controller disconnects signal from the
SmartBox™ .
h. Heater shuts down. Process begins again on a call for
heat.
FIG. 1
5
SmartBox™ SENSORS
SmartBox ™ SENSORS ARE LOCATED WITHIN 6 IN. OF EXISTING ROOM SENSORS, AND AT THE SAME HEIGHT.