Bryant BW9 - L4006 A High Limit Aquastat Control

D. L4006A High Limit Aquastat Control
The High Limit Aquastat Control determines the maximum boiler water temperature and also provides a means for protecting the boiler and heating
system from unsafe operating conditions which could damage the boiler. The aquastat is mounted in the 1/2-in. NPT control well and 3/4-in.x
1/2-in.bushing on the top of the front boiler section at the hot water outlet. The aquastat is tied in with the IBC and is factory set at 100°F water
temperature. The high limit setpoint is field adjustable and may be set anywhere between 100°F and 200°F. The field setpoint adjustment for each
installation depends on heating system requirements. The aquastat automatically resets when the boiler water temperature decreases (5–30°F
adjustable differential). The differential can be adjusted with the (white) Differential Adjustment Wheel on the aquastat and gives the flexibility
for boiler operation. The larger the differential, the longer the run cycle of the boiler.
NOTE: The maximum setpoint of the Aquastat must not exceed 200°F.
Fig. 17—Field Wiring Connections
A99168
120 VOLT
CIRCULATOR
24 VOLT
THERMOSTAT
WIRE COLOR CODE
BK = BLACK
W = WHITE
G = GREEN
Y = YELLOW
BOILER
WIRING
IN J-BOX
120 VOLT
60 HZ 1 0
POWER SUPPLY
NEUTRAL
HOT
GROUND
BK
W
G
SERVICE SWITCH
FIELD WIRING CONNECTIONS
BK
W
G
BK
W
Y
Y
SERVICE SWITCH
JUNCTION BOX
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