Calibration Procedure; Accessories; Typical Operation - Honeywell LP920A Instructions D'installation

LP920A AND B REMOTE BULB CONTROLLER
REVERSE ACTING
(MODEL B)
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
Fig. 11. LP920A discharge controller.
Automation and Control Solutions
Honeywell
1985 Douglas Drive North
Golden Valley, MN 55422
95-7273EF J.H. Rev. 2-02
MAX
R D
DIRECT ACTING
(MODEL A)
CALIBRATION MARKS
M18366
DA
M B
M
M18365
Honeywell Limited-Honeywell Limitée
35 Dynamic Drive
Scarborough, Ontario
M1V 4Z9
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
O.A.
M B
Fig. 12. LP920 limit controller used as
an economizer controller.

ACCESSORIES

Fig. 8 and 13 show accessories available for the
installation of the LP920.
MODEL NUMBER
315046B
315904B
1/2 IN. NPT
Fig. 13. Wells available for LP920 controllers.
Printed in U.S.A. on recycled
paper containing at least 10%
post-consumer paper fibers.
R.A.
N.O.
N.C.
LP920B LP920A
M B
REVERSE ACTING DIRECT ACTING
SET 75F (24C) SET 55F (13C)
M
T.R. 5F (3C) T.R. 10F (5.5C)
DESCRIPTION
7-3/8 IN. (187 MM) COPPER
7-15/16 IN. (186 MM) STAINLESS STEEL
customer.honeywell.com
COIL
D.A.
C6501
M18364