Honeywell LP916A-C Reference Manual
Remote Bulb Thermostats
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GENERAL
DESCRIPTION
The LP916 Thermostats are bleed-type controllers with a
fixed throttling range. They have a liquid-filled, remote
thermal element.
APPLICATION
Typical applications for the LP916A are duct-mounted (Fig. 1)
and mixed air control (Fig. 2). The LP916B is typically used
for fan coil unit control (Fig. 3). Typical applications for the
reverse acting LP916C are cooling coil control similar to
Figure 1 or fan coil control (Fig. 4).
LP916A-C Pneumatic
SERVICE DA TA
S5783-1
Fig. 1. Typical LP916A duct-mounted heating application.
S5785-2
Fig. 2. Typical LP916A mixed air application.
S3803-1
Fig. 3. Typical LP916B fan coil application, heating/
cooling with seasonal changeover.
Copyright © 1987 Honeywell Inc. • All Rights Reserved
LP916A-C PNEUMATIC REMOTE BULB THERMOSTATS
S22642
Fig. 4. Typical LP916C fan coil application, cooling only.
SPECIFICATIONS
Models:
LP916A: Direct Acting.
LP916B: Reverse acting at 9 or 13 psi (62 or 90 kPa)
supply pressure (Summer), direct acting at 18 psi
(124 kPa) supply pressure (Winter).
LP916C: Reverse Acting.
Maximum Safe Air Pressure:
25 psi (172 kPa).
Maximum Safe Temperature:
Duct-mounted models 190F (88C); all others 135F (57C).
Nominal Main-Line Pressure:
LP916A & C: 18 psi (124 kPa).
LP916B: 18 psi (124 kPa) heating, 9 or 13 psi (62 or
90 kPa) Cooling.
For other LP916 specifications refer to Table 1.
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Model
Setpoint
Range F/C
LP916A-C PNEUMATIC REMOTE BULB THERMOSTATS
Table 1. LP916 Specifications.
Throttling
Range F/C
Restrication
Size In.
Bulb Size
Inches
Mounting
Bracket
1LP916A1001 65-85F 3.5F 3/8 x 9 Separate
0.007
LP916A1019 65-85F or 19-30C 3.5F or 2C 0.007 1/2 x 5 Integral
1LP916A1027 65-85F 3.5F 0.007 3/8 x 9 Integral
1 Integral
LP916A1050 17-27C 1.95C 0.007 1/2 x 5 Integral
1
1
1
1
1
LP916A1100
1
1
55-95F 7.0F 0.007 3/8 x 6-11/16LP916A1035
17-27C 1.95C 0.007 3/8 x 9LP916A1068 Integral
13-35C 3.89C 0.007 3/8 x 6-11/16LP916A1076 Integral
17-27C 1.95C 0.007 3/8 x 9LP916A1084 Integral
17-27C 3.80C 0.007 3/8 x 6-11/16LP916A1092 Separate
35-115F 0.007 3/8 x 3-1/214.0F
Integral
55-95F 0.007 3/8 x 77.0FLP916A1118 Integral
65-85F or 19-30C 3.5F or 2CLP916A1126 0.005 3/8 x 9 Separate
3.5F or 2C65-85F or 19-30CLP916A1134 0.005 3/8 x 9 Integral
1
1
55-95F 7.0F 0.005 3/8 x 6-11/16LP916A1142 Integral
17-27C 1.95C 0.005 3/8 x 9LP916A1159 Integral
LP916A1175 0.007 3/8 x 77.0F or 4C40-80F or 4-27C Integral
1
0.007 3/8 x 93.5F65-85FLP916B1009 Separate
3.5F or 2C65-85F or 19-30CLP916B1017 0.007 1/2 x 5 Integral
1
1
65-85F 3.5F 0.007 3/8 x 9LP916B1025 Integral
17-27C 1.95C 0.007 3/8 x 9LP916B1041 Integral
3.5F or 2C65-85F or 19-30CLP916B1058 0.007 1/2 x 5 Integral
1
65-85F 3.5F 0.007 3/8 x 9LP916B1066 Integral
3.5F or 2C65-85F or 19-30CLP916B1074 0.005 3/8 x 9 Separate
3.5F or 2C65-85F or 19-30CLP916B1082 0.005 1/2 x 5 Integral
1
17-27C 1.95C 0.005 3/8 x 9LP916B1090 Integral
3.5F or 2C65-85F or 19-30CLP916B1108 0.005 3/8 x 9 Integral
1
1
65-85F 3.5F 0.007 3/8 x 9LP916C1007 Integral
17-27C 1.95C 0.007 3/8 x 9LP916C1015 Integral
LP916C1023 60-80F or 16-27C 3.5F or 2C 0.007 3/8 x 9 Integral
1
1
1
35-115F 0.007 3/8 x 3-1/214.0FLP916C1072 Integral
55-95F 0.007 3/8 x 77.0FLP916C1080 Integral
3.5F or 2C65-85F or 19-30C 0.007 1/2 x 5LP916C1049 Integral
3.5F or 2C65-85F or 19-30CLP916C1098 0.005 3/8 x 9 Integral
1
40-80F or 4-27C 0.007 3/8 x 77.0F or 4CLP916C1114 Integral
1
Inactive or obsolete.
3
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LP916A-C PNEUMATIC REMOTE BULB THERMOSTATS
OPERATION
LP916A (Direct Acting)
When temperature at the sensing element falls below setpoint
of the LP916A, branchline pressure to the normally open
(n.o.) valve is lowered, and the valve is modulated open to
maintain setpoint temperature.
LP916B (Reverse/Direct Acting)
With main-line pressure at 13 psi (90 kPa) for all except
LP916B1058 which requires 9 psi (62 kPa), the LP916B
operates reverse acting. As the sensed temperature
increases, the branchline pressure decreases and chilled
water flow increases with a n.o. valve.
With a high main-line pressure of 18 psi (124 kPa) or above,
the LP916B operates direct acting. As the sensed
temperature increases, the branchline pressure increases
and hot water flow decreases with a n.o. valve.
LP916C (Reverse Acting)
When the LP916C is used with a normally open valve for
cooling, branchline pressure drops with a rise in sensed air
temperature and the n.o. valve is modulated open to maintain
setpoint temperature.
CLEANING
Remove cover. Use cleaning solvent to clean all surfaces.
Clean the element and capillary tubing, making certain
neither is damaged or kinked. Do not bend the capillary
tubing in a short radius.
OPERATIONAL CHECK
Use gage adaptor. Insert the gage into the gage tap (Fig. 5)
on the front of the device. Set main-line pressure to 18 psi
(124 kPa), or 13 psi (90 kPa) for LP916B Summer
application. Slowly turn the setpoint knob above and below
bulb ambient temperature. The branchline pressure should
vary from 3 to 13 psi (21 to 90 kPa) pressure, or 13 to 3 psi
(90 to 21 kPa) for reverse acting application within the rated
throttling range. If operation is not satisfactory, recalibrate and
recheck (see CALIBRATION). Turning the knob to above 13
psi (90 kPa) should build branch line to within 2 psi (14 kPa)
of main.
GAGE TAP
NORMAL
COOLER
WARMER
MAINTENANCE
EQUIPMENT REQUIRED
— Commercial Cleaning Solvent or Degreaser.
— Gage Adaptor CCT729A.
— Gage 305965, 0 to 30 psi.
— 5/64-inch Hex wrench.
WARNING
Careless handling of solvents can result in permanent
damage to the respiratory system or skin. Avoid
prolonged inhalation of vapors or contact with skin.
C2861
Fig. 5. LP916 Gage tap location.
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