Honeywell LP916A-C Reference Manual

LP916A-C Pneumatic

Remote Bulb Thermostats

SERVICE DATA

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).

S3803-1

Fig. 3. Typical LP916B fan coil application, heating/ cooling with seasonal changeover.

S5783-1

Fig. 1. Typical LP916A duct-mounted heating application.

S5785-2

Fig. 2. Typical LP916A mixed air application.

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LP916A-C PNEUMATIC REMOTE BULB THERMOSTATS

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.

S22642

Fig. 4. Typical LP916C fan coil application, cooling only.

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LP916A-C PNEUMATIC REMOTE BULB THERMOSTATS

		Table 1. LP916 Specifications.
		Setpoint	Throttling	Restrication	Bulb Size	Mounting
Model		Range F/C	Range F/C	Size In.	Inches	Bracket
LP916A1001	1	65-85F	3.5F	0.007	3/8 x 9	Separate
LP916A1019		65-85F or 19-30C	3.5F or 2C	0.007	1/2 x 5	Integral
LP916A1027	1	65-85F	3.5F	0.007	3/8 x 9	Integral
LP916A1035	1	55-95F	7.0F	0.007	3/8 x 6-11/16	Integral
LP916A1050	1	17-27C	1.95C	0.007	1/2 x 5	Integral
LP916A1068	1	17-27C	1.95C	0.007	3/8 x 9	Integral
LP916A1076	1	13-35C	3.89C	0.007	3/8 x 6-11/16	Integral
LP916A1084	1	17-27C	1.95C	0.007	3/8 x 9	Integral
LP916A1092	1	17-27C	3.80C	0.007	3/8 x 6-11/16	Separate
LP916A1100	1	35-115F	14.0F	0.007	3/8 x 3-1/2	Integral
LP916A1118	1	55-95F	7.0F	0.007	3/8 x 7	Integral
LP916A1126		65-85F or 19-30C	3.5F or 2C	0.005	3/8 x 9	Separate
LP916A1134		65-85F or 19-30C	3.5F or 2C	0.005	3/8 x 9	Integral
LP916A1142	1	55-95F	7.0F	0.005	3/8 x 6-11/16	Integral
LP916A1159	1	17-27C	1.95C	0.005	3/8 x 9	Integral
LP916A1175		40-80F or 4-27C	7.0F or 4C	0.007	3/8 x 7	Integral
LP916B1009	1	65-85F	3.5F	0.007	3/8 x 9	Separate
LP916B1017		65-85F or 19-30C	3.5F or 2C	0.007	1/2 x 5	Integral
LP916B1025	1	65-85F	3.5F	0.007	3/8 x 9	Integral
LP916B1041	1	17-27C	1.95C	0.007	3/8 x 9	Integral
LP916B1058		65-85F or 19-30C	3.5F or 2C	0.007	1/2 x 5	Integral
LP916B1066	1	65-85F	3.5F	0.007	3/8 x 9	Integral
LP916B1074		65-85F or 19-30C	3.5F or 2C	0.005	3/8 x 9	Separate
LP916B1082		65-85F or 19-30C	3.5F or 2C	0.005	1/2 x 5	Integral
LP916B1090	1	17-27C	1.95C	0.005	3/8 x 9	Integral
LP916B1108		65-85F or 19-30C	3.5F or 2C	0.005	3/8 x 9	Integral
LP916C1007	1	65-85F	3.5F	0.007	3/8 x 9	Integral
LP916C1015	1	17-27C	1.95C	0.007	3/8 x 9	Integral
LP916C1023		60-80F or 16-27C	3.5F or 2C	0.007	3/8 x 9	Integral
LP916C1049	1	65-85F or 19-30C	3.5F or 2C	0.007	1/2 x 5	Integral
LP916C1072	1	35-115F	14.0F	0.007	3/8 x 3-1/2	Integral
LP916C1080	1	55-95F	7.0F	0.007	3/8 x 7	Integral
LP916C1098		65-85F or 19-30C	3.5F or 2C	0.005	3/8 x 9	Integral
LP916C1114	1	40-80F or 4-27C	7.0F or 4C	0.007	3/8 x 7	Integral

1 Inactive or obsolete.

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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.

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.

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
<![if ! IE]> <![endif]>WARMER	<![if ! IE]> <![endif]>COOLER

C2861

Fig. 5. LP916 Gage tap location.

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