Install Instructions

LP920A AND B REMOTE BULB CONTROLLER
REVERSE ACTING
(MODEL B)
MAX
R D
DIRECT ACTING
(MODEL A)
CALIBRATION MARKS
M18366
Fig. 10. Throttling range lever (models A and B).
Calibration Procedure
NOTE: The LP920 is factory calibrated and does not
normally require field calibration.
1. Measure the element temperature.
2. Move the setpoint to the indicated temperature.
3. Measure the branch line pressure.
4. Using a 5/64 in. (1.98 mm) allen wrench, adjust the
hex screw in the center of the setpoint knob to
achieve a 8 psi (55 kPa) branch line pressure.
TYPICAL OPERATION
LP920 Discharge Controller
When using an LP920A in a heating system, a drop in
temperature at the sensor lowers the branch line
pressure. See Fig. 11. This opens the normally open
valve further to increase the flow of heating medium to
the coil.
COIL
M
M
DA
B
M18365
Fig. 11. LP920A discharge controller.
LP920A and B Limit Controllers
When the LP920A is used as an economizer controller in
a mixed system (located in the mixed air duct) it
modulates outside and return air dampers to maintain a
constant mixed air temperature. See Fig. 12. When the
mixed air temperature exceeds the primary controller
setpoint, 100 percent outside air results.
The LP920B limit controller (located in the outside air
duct) closes the outside air damper and opens the return
air damper as the outside air temperature exceeds the
LP920B setpoint.
E.P. DAMPER
RELAY OPERATOR
D.A.
C6501
Fig. 12. LP920 limit controller used as
an economizer controller.
ACCESSORIES
Fig. 8 and 13 show accessories available for the
installation of the LP920.
M
M B
COIL
N.O.
N.C.
O.A.
R.A.
LP920B
REVERSE ACTING
SET 75F (24C)
T.R. 5F (3C)
M B
LP920A
DIRECT ACTING
SET 55F (13C)
T.R. 10F (5.5C)
MODEL NUMBER DESCRIPTION
315046B 7-3/8 IN. (187 MM) COPPER
315904B 7-15/16 IN. (186 MM) STAINLESS STEEL
M18364
Fig. 13. Wells available for LP920 controllers.
1/2 IN. NPT
Automation and Control Solutions
Honeywell Honeywell Limited-Honeywell Limitée
1985 Douglas Drive North 35 Dynamic Drive
Golden Valley, MN 55422 Scarborough, Ontario
M1V 4Z9
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