resideo Immersion Wells and Compression Fittings Installation Guide

: June 7, 2024
: resideo

Table of Contents

Immersion Wells and Compression Fittings
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Immersion Wells and Compression Fittings

Immersion Wells and Compression Fittings
FOR TEMPERATURE CONTROLLERS

PRODUCT DATA

121371B IMMERSION WELL
112632AA IMMERSION WELL
107324A ELEMENT HOLDER
104484A COMPRESSION FITTING
APPLICATION
Immersion wells, compression fittings and element holders are used with Aquastat® Temperature Controllers to hold the temperature sensing bulb in the controlled medium. Immersion wells and compression fittings also prevent leakage of the controlled medium.

FEATURES
· Immersion wells and compression fittings are available to fit a 1/2-14 or 3/4-14 NPT tapping with a range of insulation depths.
· Immersion wells and compression fittings are available in a variety of lengths and diameters.
· Immersion wells and compression fittings are available in a variety of materials, to suit the application. Materials include: brass, copper, stainless steel, mild steel or Monel.
· Element holders support the capillary and bulb or an averaging element in duct applications.
· Bulb shields protect the sensing bulb from sun and weather with the bulb installed outdoors.
· Accessories, including mounting clips, heatconductive compound, waste nuts, a pipe strap and a well adapter, are available for mounting sensing bulbs in various applications.
· Immersion wells allow heat transfer while protecting the sensing bulb from contact with the controlled medium.
· Immersion wells permit removal of the sensing bulb for testing or replacement without draining the system.
· Compression fittings seal the boiler and allow bulb insertion directly into the controlled medium.

Contents
Application ……………………………………………………………….. 1 Features …………………………………………………………………… 1 Specifications …………………………………………………………… 2 Ordering Information …………………………………………………. 2 General Information ………………………………………………….. 7 Installation ……………………………………………………………….. 8 Checkout ………………………………………………………………….. 14 Cross Reference ……………………………………………………….. 14

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IMMERSION WELLS AND COMPRESSION FITTINGS

SPECIFICATIONS
Models: Immersion Wells: Allow heat transfer while protecting
sensing bulb from controlled medium and seal off tapping to permit bulb removal without draining the boiler. Available in copper, stainless steel, mild steel and Monel. See Table 1 for copper. See Table 2 for stainless steel, mild steel and Monel. Compression Fittings: Allow bulb insertion directly into the controlled medium with boiler draining. Can also be used to provide positive seal in duct applications. Available in brass and stainless steel. See Table 3. Element Holders: Support bulb and capillary or averaging element in a duct. See Table 4.
Dimensions: See Tables 1, 2, 3 and 4, and Fig. 1 and 2.
Temperature Ratings:
IMPORTANT
Do not exceed the maximum temperature rating of the controller element.
Wells: Copper: 300°F (149°C) maximum. Other Materials: Maximum temperature rating limits of the controller sensing bulb and capillary.
Capillary Compression Fittings: 250°F (121°C) maximum.

Element Holders: 311266D Bulb Holder: -40°F to +100°F (-40°C to +38°C). Other Element Holders: Maximum temperature rating limits of the controller sensing bulb and capillary.
Maximum Pressure Ratings: Copper Wells: 255 psi (1758 kPa) at 300°F (149°C). Other Wells: 1500 psi (10,342 kPa) at 700°F (371°C). Capillary Compression Fittings:
Water: 50 psi (345 kPa) Air: 15 psi (103 kPa).
Accessories: See Tables 5 and 6.

PACKING NUT
TUBING

INSULATION DEPTH

FITTING FOR 1/2 OR 3/4-14 NPT TAPPED HOLE

SLOTTED BRASS WASHERS (4)
COMPOSITION DISK

MINIMUM INSERTION LENGTH APPROXIMATELY 4-3/4 IN.
M17260

Fig. 1. Capillary compression fitting dimensions and components.

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IMMERSION WELLS AND COMPRESSION FITTINGS

WELL SPUD. FITS 1/2 OR 3/4-14 NPT TAPPED HOLE

1/8-1/2 in. OF THREADS MAY

121371A-S

EXTEND INTO CONTROLLED MEDIUM

123869A-123872A

(LESS MOUNTING CLAMP)

MOUNTING CLAMP
MOUNTING FLANGE

INSULATION DEPTH

WELL SHELL.
INSERTION/MAX BULB LENGTH

FITS 1/2 OR 3/4-14 NPT TAPPED HOLE

NOTE: 123870F HAS DUAL DIAMETER WELL SHELL.
122555A,B

MOUNTING FLANGE

INSULATION DEPTH

FITS 1/2 OR 3/4-14 NPT TAPPED HOLE

INSERTION/MAX BULB LENGTH
122555E DUAL DIAMETER WELL

MOUNTING FLANGE
SET SCREW

INSULATION DEPTH

INSERTION/MAX BULB LENGTH

FITS 1/2 OR 3/4-14 NPT TAPPED HOLE

123732AA

INSULATION DEPTH

INSERTION/MAX BULB LENGTH
FITS 1/2 OR 3/4-14 NPT TAPPED HOLE

138134B

MOUNTING FLANGE

INSULATION DEPTH

INSERTION/MAX BULB LENGTH

FITS 1/2 OR 3/4-14 NPT TAPPED HOLE

138134E DUAL DIAMETER WELL

MOUNTING FLANGE

INSULATION DEPTH

INSERTION/MAX BULB LENGTH

FITS 1/2 OR 3/4-14 NPT TAPPED HOLE

1/8-1/2 in. OF THREADS MAY EXTEND INTO CONTROLLED MEDIUM

112620AA-112639AE

SPRING CLIP

INSULATION DEPTH

WELL SHELL
INSERTION/MAX BULB LENGTH

Fig. 2. Immersion well dimensions and components.

M17259A

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Shell ID/ Spud in in. Bulb x 14 NPT Diameter

1/2

3/8

Insertion/ Max Bulb
Length
3

1/2

3/4

3/8

3-1/2 3-3/4
4-1/4 4-1/4 3

3-1/2

3/8 + 5/8 3

1/2

4-1/4

8-1/4

Table 1. Copper Immersion Wells.

Insulation Depth
1-1/2
3 1-1/2 1-1/2
1-1/2 4-1/2 1-1/2
3
4-1/2
1-1/2 2-1/4 4-1/2
2-1/4 4-1/2 1-1/2 4 1-1/2

Capillary Diameter 5/64 —
5/64
1/8 — 1/8
5/64 — 5/64
—
—
5/64 —
1/8

Includes 121371 Mounting Clamp — Spud setscrew for armored capillary, plug 121371 Mounting Clamp 121371 Mounting Clamp 112721 Spring Clip Plastic sleeve on well tube 112721 Spring Clip 112721 Spring Clip 121371 Mounting Clamp — 121371 Mounting Clamp 121371 Mounting Clamp, plastic sleeve — Plastic sleeve on well tube — Plastic sleeve on well tube 121371 Mounting Clamp — Plastic sleeve on well tube — Plastic sleeve on well tube
112721 Spring Clip

Part Number 121371A 123869A 123732AA 121371L 121371P 112620AA 123869B 112622AA 112626AA 121371B 123870A 121371M 123171N 123871A 123871B 122555D 122555A 121371Q 138134B 122555B 122555C 138134E 122555E 112630AA 112634AA 112630AB

Table 2. Stainless Steel, Mild Steel, and Monel Immersion Wells.

Spud in in. x 14 NPT

Shell ID/ Bulb
Diameter

1/2

3/8

1/2

Insertion/ Max Bulb
Length 3
4-1/4

Insulation Depth
1-1/2 1
4 1

Capillary Diameter 5/64 1/8
1/8 1/8

Material
Stainless steel
Mild steel
Stainless steel
Stainless steel
Stainless steel

Includes

Part Number

121371 Mounting Clamp 121371E

112721 Spring Clip 112721 Spring Clip

112623AA 112624AA

112721 Spring Clip

112628AA

112721 Spring Clip

112632AA

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Material Brass

Spud 1/2-14 NPT
3/4-14 NPT

Table 3. Capillary Compression Fittings.

Maximum Bulb Diameter Insulation Depth

1/2 in.

1-5/16 in.

11/16 in.

1-1/2 in. 2 in. 1-5/8 in. 1-1/2 in.

Capillary Diameter 5/64 in. 1/8 in. 5/64 in. 5/64 in. 5/64 in. 1/8 in.

Part Number 104484A 7617M 104484C 7617ABY 104484B 7617P

Application Bulb holders

Table 4. Element Holders for Duct-Mount Applications .

Length Plate Size
8-5/8 in. 2-3/4 in. x 1-3/4 in.

Description
Supports capillary and bulb in duct; mounting screws not included.

Part Number

2-3/4 in x 3 in.

M17275A
107324A

14 in.

3-1/4 in x 3-1/4 in.

Holds 1 or 2 elements in 0°F to 100°F air; grommet holds one 5/64 in. and one 1/8 in. diameter capillary; helps reduce airflow through opening in duct.

Averaging

—

element

holders

Mounting clip; use with grommet; mounting screws not included; one required per clip.

M17276A
131524A

311266D

M17277A

Use with 1/2 in. EMT thinwall conduit where duct access is limited. Kit includes 4 in. (101 mm) cover plate, 1/2 in. EMT compression fitting, 3/16 in. (5 mm) rubber grommet, clamp assembly, wire ties and mounting screws.

M17271
314439

7640HX

M17279

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Description Mounting clamp

Table 5. Immersion Well Accessories .

Application

Size in in. (except where noted)

Holds capillary in place on 1/2 or 3/4 in. well spud; 5/64

123869A-123872A;

capillary

122554A,B; 12255A,B,D,E; and

138134B-F Immersion Wells.

Spring clip

Part Number
M17274
121371AA

Holds capillary in place on 1122620AA-112639AB Immersion Wells.

M17288
32002656-001
1/2 in well spud; 5/64 capillary 104488
1/2 in. well spud; 1/8 capillary. 112721 3/4 in. well spud; 1/8 capillary. 112720

Heat-conductive compound

Improves heat conduction in 4 oz. (118 ml) well applications where bulb does not fit tightly.

M17280

Single application tube (1/2 oz)

M17281
107408

Well Adapter

Adapts well with setscrew on spud; for use with direct insertion bulb or 121371AA Mounting Clamp.

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M17282
120650
M17283
124904

IMMERSION WELLS AND COMPRESSION FITTINGS

Description Bulb shield assembly

Table 6. Accessories for Duct-Mount Applications

Application

Size

Shields bulb from weather; 6 in. (152 mm) long; holds 3/8 less mounting screws and in. and 1/2 bulbs. split plug.

Part Number

Shields bulb from weather; 7 in. (118 mm) long, clip holds includes mounting screws 3/8 in. bulb. and 33578 Split Plug.

Pipe Strap

Fastens bulb to outside of 4-1/2 in. (114 mm) long; used

pipe.

with up to 3/4 in. OD pipe.

107323A

M17284

34886A

M17285

M17286
105900

GENERAL INFORMATION
Immersion Wells
An immersion well consists of a metal tube, called the well shell, closed on one end. A well spud externally threaded to fit standard boiler tappings is welded or brazed on the open end. See Fig. 1. The well is inserted into the tank and the temperature sensing bulb is inserted into the well. The sensing bulb never touches the controlled medium. Because the well conducts heat rapidly, the bulb responds quickly and accurately to temperature changes in the controlled medium.
An immersion well protects the temperature sensing bulb from mechanical damage or damage due to chemical interaction with the controlled medium. Also, a well permits removal of the sensing bulb for testing or control replacement without draining the system. The threaded fitting of the well spud provides a tighter seal than a packing nut applied to the capillary.
Material Selection
The immersion well material must conduct heat readily and resist corrosive and electrolytic action (especially in brine solutions and when the well is a different material than the container). The material must also resist fluid contamination from chemical reaction with the well and withstand high temperatures. Most immersion wells are copper because of

its high conductivity. Stainless steel, mild steel and Monel wells are also available for applications requiring higher maximum temperature and pressure ratings or greater corrosion resistance. Some copper wells are available with a plastic sleeve over the tube to reduce electrolytic and corrosive activity.
Well Sizing
Major factors in selecting well size are:
–size of the boiler tapping.
–bulb diameter.
–insulation depth.
–insertion length.
Immersion wells are available to fit standard 1/2-14 NPT and 3/4-14 NPT tappings. Sensing bulbs are 3/8, 1/2 or 11/16 in. in diameter with well shells designed to fit these diameters. The bulb should fit tightly in the shell. If the bulb fits loosely, fill the space between the shell and bulb with heatconductive compound to ensure maximum heat transfer. Many temperature controllers ship with heat-conductive compound; available in 4-oz cans and 1/2-oz singleapplication tubes. See Table 4.

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he nominal length of the spud, including the full length of the threads and the hex, defines the insulation depth. Depending on the characteristics of the tapping, 1/8 to 1/2 in. of the threaded end of the spud can extend into the controlled medium. Consider this additional length when determining how far the well extends into the controlled medium.
The length of the well shell starting at the end of the spud defines the insertion length. This is the active part of the well where the fastest heat transfer occurs. The bulb should be the same length as the well shell; however, the well shell can be longer, but not shorter, than the length of the bulb. Longer shells require inserting the bulb until the end touches the well bottom. Shorter shells do not expose the full length of the bulb to the temperature of the controlled medium, inhibiting proper temperature controller operation.
Securing Bulb in Well
REMOTE BULB APPLICATIONS Securing the capillary at the spud with a spring clip or a mounting clamp holds the sensing bulb securely in place. See Fig. 1. Use the spring-loaded clip on well spuds with no mounting flange. Slip it over the capillary and snap it in place in the end of the spud. The mounting requires sizing to fit both the spud and the capillary diameter. The mounting clamp requires wells with a mounting flange at the spud end. The jaws adjust to fit both 1/2 and 3/4 in. spuds, and it holds a 5/64 in. capillary. Wells are available with and without the matching spring clip or mounting clamp. This mounting hardware is also available separately.
A few wells have a setscrew in the spud. These wells are designed for use on controllers with an armored capillary that has a brass plug at the sensing bulb end; for example, R8182H,J.
DIRECT INSERTION APPLICATIONS Most direct insertion controllers include provision for clamping the controller case on the immersion well spud. This requires a well spud with a mounting flange at the end. If the well spud has a setscrew, but no mounting flange, a 124904 Well Adapter can provide the necessary flange. See Fig. 3. The well adapter is shipped with several directinsertion controllers.

BACK OF
CASE

SETSCREW
IMMERSION WELL CLAMP

BOILER WALL

Capillary Compression Fittings
A capillary compression fitting includes a spud, several aligning washers, a neoprene packing ring and a packing nut. The spud is internally threaded to hold the packing material and the packing nut and externally threaded to fit standard boiler tappings. The washers and packing ring are sized to fit a particular capillary diameter.
Capillary compression fittings are used to replace an immersion well when the sensing bulb of a remote bulb controller requires direct insertion into the controlled medium. The fitting seals around the capillary. However, compression fittings cannot seal off against as much pressure as immersion wells. Capillary compression fittings can be used in duct applications to minimize air leakage from the duct; a waste nut is recommended to provide a secure mounting.
Material Selection
Capillary compression fittings are available in brass and stainless steel. In hydronic applications, brass fittings with copper sensing bulbs are used and stainless steel is used with all other fittings to minimize electrolytic action.
Sizing
Capillary compression fittings must fit the tapping and the capillary diameter. Because the spud must slip over the bulb during installation, 11/16 in. bulbs require 3/4 in. spuds.
Element Holders
Bulb holders are used to support a remote bulb and capillary in a duct, but are not suitable for hydronic applications. A bulb holder must be selected according to the length needed to support the bulb in the main airstream and the need for plugging the opening in the duct wall.
For best response, string averaging elements evenly back and forth across the duct. The element is held in place with either perforated pipe strap or 314439 Mounting Clips. If access to the duct is limited, use the 7640HX Duct Mounting Kit. Always use a grommet to protect the element from abrasion where it enters the duct.
NOTE: To minimize heat loss through the fitting, use a waste nut and compression fitting.
INSTALL ATION

WELL CLAMP SCREW

WELL ADAPTER

WELL SPUD
SENSING BULB

WELL SHELL
M17261

Fig. 3. Mounting direct insertion controller case on well spud.

When Installing this Product…
1. Read these instructions carefully. Failure to follow them could damage the product or cause a hazardous condition.
2. Check the ratings given in the instructions and on the product to make sure the product is suitable for your application.
3. Installer must be a trained, experienced service technician.
4. After installation is complete, check out product operation as provided in these instructions.

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WARNING
Severe Scalding Hazard. Contact with hot liquid can cause severe injury or death. Drain system before beginning well or compression fitting installation.
WARNING
Electrical Shock Hazard or Equipment Damage Hazard. Can cause sever injury, death or short equipment circuitry. Disconnect all power supplies before installation.
Most equipment manufacturers provide a tapping for temperature controller sensing element insertion. The tapping should be located to measure average system temperature.
IMPORTANT Always install the sensing element away from hot or cold water inlets, steam coils, and locations where the well pressure rating will be exceeded.
1. Turn off the power. 2. If the system is filled, drain it to a point below the boiler
tapping or sensing element location. 3. If no tapping is provided, prepare one, properly
threaded, at the desired location.
Immersion Well Mounting
Instructions for mounting the well in the tapping and using the capillary mounting clamp or spring clip in remote bulb applications follow. Consult the appropriate Aquastat® Controller instructions for mounting the controller on the well in direct insertion applications. Direct insertion applications usually require using wells with a mounting flange on the spud.
1. Coat threads with a moderate amount of pipe dope, leaving two end threads bare. See Fig. 4.
NOTE: TeflonTM tape can also be used.
2. Screw the immersion well into the tapping and tighten securely.
APPLY A MODERATE AMOUNT OF PIPE COMPOUND (LEAVE TWO END THREADS BARE).
M17262
Fig. 4. Proper application of pipe dope.
Insert Sensing Bulb in Well
For good temperature response, the immersion well must fit the sensing element or bulb tightly and rest against the bottom of the well.
NOTE: If necessary, bend the tubing to hold the bulb against the bottom of the well.

IMPORTANT Any bends made in the piping must be gradual to prevent breaks in the tubing and subsequent loss of fill.
For faster heat transfer, use heat-conductive compound to fill the space between the bulb and the well. A tube of heat-conductive compound ships with Aquastat Controllers. The compound is also available as an accessory. See Table 5. Use the following procedure when installing the compound:
1. Fill the well with compound. 2. Coat the bulb generously before inserting it into the
well. 3. Move the bulb up and down inside the well to ensure
even distribution of compound.
Securing Bulb with Mounting Clamp
Use the 121371 Mounting Clamp only on wells with a mounting flange on the spud end.
1. Loosen the draw nut and spread the jaws of the clamp with a screwdriver. See Fig. 5.
2. Slide the clamp jaws over the spud mounting flange (point A in Fig. 5).
3. Adjust the tubing to fit through the mounting clamp groove (point B in Fig. 5).
IMPORTANT When tightening the draw nut, be careful not to damage the capillary.
4. Tighten the draw nut so that the retainer clamp attaches firmly to the well spud and holds the tubing securely in place.

JAWS
SPREAD JAWS TO FIT OVER RIDGE ON WELL SPUD
SCREWDRIVER
MOUNTING CLAMP

DRAW NUT
B

MOUNTING CLAMP

SPUD BULB

WELL

TUBING
A

M8777

Fig. 5. Fastening bulb in well using mounting clamp.

Securing Bulb with Spring Clip
The spring clip can be used with any well with the appropriately size spud. Wells without a mounting flange on the spud require a spring clip.

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NOTE: The spring clip does not hold the capillary as securely as does the mounting clamp. See Table 5 for spring clip part numbers.
1. Slide the clip over the capillary with the prongs facing the well.
2. Push the clip as far as possible into the spud. See Fig. 6.
NOTE: Make sure the bulb remains bottomed in the well.

FITTING (INCLUDING WELL)

APPROX. 3-3/8 IN. INSERTION LENGTH

7. Slide the seal assembly into the fitting. Make sure the sensing bulb extends the desired distance into the controlled medium. See Fig. 2.
8. Tighten the packing nut.
1/2 in. (13 mm) PIPE THREAD FOR 1/2 in. (13 mm) CAPSULES 3/4 in. (19 mm) PIPE THREAD FOR 11/16 in. (17 mm) CAPSULES
SPUD
CAPILLARY TUBING
COMPOSITION DISK (SLOTTED)

TUBING SPRING CLIP

BULB

M17263

Fig. 6. Mounting spring clip into well spud.

Securing Bulb in Wells with Setscrew
Wells with a spud setscrew are designed for use with controllers that have armored capillary with a brass collar at the bulb end of the armor. The setscrew tightens against the brass collar. See Fig. 7. These wells can be adapted for use with 5/64 in. capillary by adding the 124904 Well Adapter and the 121371 Mounting Clamp Assembly. See Fig. 3.

M17264
Fig. 7. Mounting armored capillary in well with setscrew.
Capillary Compression Fittings
1. Coat external spud threads with a moderate amount of pipe dope, leaving two end threads bare. See Fig. 4.
NOTE: Teflon tape can also be used.
2. Screw the spud into the tapping and tighten securely. 3. Place the packing nut on the tubing. 4. Slide the bulb completely through the fitting. 5. Place the composition disk and the four slotted brass
washers on the tubing in the order shown in Fig. 8. 6. Turn the brass washers so that the slots are 180
degrees apart and the small tabs are in the mating slots.

PACKING NUT

SLOTTED WASHERS ASSEMBLED IN PAIRS THUS-
M17258

Fig. 8. Capillary compression fitting assembly.

Element Holders
Use element holders to mount air temperature sensors in a duct. Locate the sensing element where air at representative temperatures can circulate around it. In a plenum application, locate the element far enough from the combustion chamber to avoid the effect of direct radiation.

Bulb Holders
1. Cut a hole large enough to admit the bulb and holder in the duct or plenum at the mounting location.
2. Drill holes for the bulb holder mounting screws. 3. Mount the bulb and capillary on the holder. See Fig. 9
through 11.
107324A and 131524A Bulb Holders
Use these bulb holders to mount one bulb in a duct or plenum. See Fig. 9 and 10. If necessary, shorten holders by using pliers to flex the channel at one of the notches until it separates.
311266D Bulb Holder
Use this bulb holder to mount one or two bulbs in a duct where temperatures do not exceed 100°F (38°C). The removable plug in the mounting plate allows insertion of a thermometer to check duct air temperature. See Fig. 11 for installation details.

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PINCH TOP EDGES OF HOLDER TOGETHER AT EACH SEGMENT
CAPILLARY TUBING
SENSING BULB

BE SURE EXTENSION TUBE IS UNDER BULB HOLDER, AS SHOWN

M7217

Fig. 9. Installing capillary in 107324A and 131524A Bulb Holders.

INDOOR BULB

SCREW HOLES IN WALL OF PLENUM

CAPILLARY TUBING

KEEP BULB WELL ABOVE COMBUSTION CHAMBER
COMBUSTION CHAMBER
M17265
Fig. 10. Mounting bulb holder in furnace plenum.

1(3-35/)3(88-13/)4

THERMOMETER BULB
14 (356)

3(8-13/)4 1(4-51/)8
2(7-30/)4 ACCESS HOLE

ADJUSTABLE SPRING CLIPS (2)
CONTROLLER BULB

2-1/4 x 2-1/4 (57 x 57) APPROXIMATE HOLE IN DUCT FOR INSTALLATION

RUBBER GROMET
NO. 8 SHEET METAL MOUNTING SCREWS (2)

M7355

Fig. 11. Mounting sensing bulb and 311266D Bulb Holder in duct.

IMMERSION WELLS AND COMPRESSION FITTINGS

NOTE: Dimensions shown in in. (mm).
Duct Mounting with Capillary Compression Fitting
In some duct-mount application, it is desirable to use a compression fitting to reduce air leakage at the sensing element location. For these applications, first mount a waste nut on the duct to ensure secure mounting. See Fig. 12. See Table 6 for part numbers.
NOTE: Do not use this mounting method for liquid applications.

WASTE NUT

DUCT WALL

CAPILLARY COMPRESSION
FITTING

CAPILLARY TUBING

BULB (CAPSULE)

M17266

Fig. 12. Mounting sensing bulb in duct using waste nut and compression fitting.

Averaging Element Holders
The averaging element must be supported so it is distributed evenly across the entire height and width of the duct. It can be fastened to perforated strap iron (see Fig. 13) or mounted with 314439 Mounting Clips (see Fig. 14). This type of mounting requires threading the element through a grommet inserted in a hole in the duct wall.
For ducts with limited access, the 7640HX Averaging Element Mounting Kit allows mounting the element through a single hole in the side of the duct. This kit requires a length of 1/2 in. EMT conduit. See Fig. 15.

CAPILLARY TUBING

ELEMENT

GROMMET

DUCT WALL

WIRE FASTENINGS

M17269

Fig. 13. Mounting averaging element with perforated strap iron.

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CAPILLARY

TUBING

GROMMET

AVERAGING ELEMENT

USE NO. 10 SHEETMETAL SCREWS

DUCT WALL

314439 CLIP
BEND HERE IF NECESSARY
M17289

Fig. 14. Mounting averaging element with 314439 Mounting Clips.

8. Place the split plug (provided with 34886A; or order 107323A Split Plug separately) around the tubing and move the bulb and shield into mounting position as a single unit.
9. Push the split plug into the hole until it is wedged securely in place.
10. Fasten the shield on the wall with screws (provided with 34886A).
11. If the tubing is properly shaped and the split plug installed as directed, the shield covers the split plug and conceals the hole in the wall.

PLUG HOLE WITH ACCEPTABLE MATERIAL
OUTDOOR SENSING BULB

EXTENSION TUBE

3/4 IN. (19 mm) HOLE IN WALL
CAPILLARY TUBING

GROMMET

WIRE TIES

CAPILLARY
CONDUIT COMPRESSION FITTING
4 in. COVER PLATE

1/2 in. EMT CONDUIT (OBTAIN LOCALLY)

DUCT WALL

M17270

AVERAGING ELEMENT

Fig. 15. Mounting averaging element with 7640HX Averaging Element Mounting Kit.

Bulb Shields
A bulb mounted outdoors requires protection of a bulb shield.
1. Expose the bulb to representative air temperature but not direct sunlight.
2. Mount it high enough so: a. Accumulated snow, leaves or other debris cannot obstruct air circulation around it. b. Children cannot reach it. c. Avoid vents from the building.
3. Drill a 3/4 in. (19 mm) hole in the outside wall. 4. Bring the sensing bulb through the hole. 5. Mount the bulb in the bulb shield. See Fig. 16. 6. If the seal-off tube extends outside the shield, bend it
under the shield. 7. Hold the shield over the mounting location and form a
small-radius bend in the tubing.

BULB SHIELD

M17272A

Fig. 16. Mounting bulb in bulb shield.
Strap-On Mounting
Occasionally, applications require the sensing bulb to be strapped to the outside of a pipe. For these applications, use either the 105900 Pipe Strap or metal hose clamps. The pipe strap fits pipe up to 3/4 in. OD.
External mounting of the sensor produces a slight offset in the temperature control point. Typically, the control temperature increases as much as 5°F (2.8°C) with a bare sensor strapped to the discharge pipe. Applying insulation around the sensor and pipe decreases the offset. Insulation must be used if large fluctuations in ambient temperature occur near the pipe.
Mount the bulb on the pipe as follows:

CAUTION
Significant Calibration Shift Hazard. Overtightening clamps distorts bulb calibration. Do not overtighten hose clamps.
1. Secure the bulb to the pipe with a 105900 Pipe Strap or metal hose clamps. See Fig. 17 and 18.
2. If necessary, cover the bulb and pipe with foam rubber insulation that extends at least 6 in. (152 mm) beyond both ends of the bulb. See Fig. 19.
IMPORTANT Do not allow the duct tape to come into contact with the pipe.
3. Secure foam rubber with duct tape.

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IMMERSION WELLS AND COMPRESSION FITTINGS

T-CLAMP

CAPILLARY TUBE

BULB

CAPILLARY TUBING

SUPPLY WATER PIPE

M8836

Fig. 17. Mounting bulb to pipe with pipe strap.
NOTE: When using a pipe strap, the maximum pipe OD is 3/ 4 in.

M17267

METAL HOSE CLAMPS

Fig. 18. Mounting bulb to pipe with metal hose clamps.

CAPILLARY TUBE

DUCT TAPE

FOAM RUBBER WRAP (EXTEND 6 in. (152 mm) BEYOND ENDS OF BULB)

PIPE
M17268
Fig. 19. Covering bulb and pipe with foam rubber insulation.

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CHECKOUT
When installation is complete, check it as follows:
1. Visually inspect the fittings in hydronic applications for leakage.
2. If necessary, tighten these fittings. 3. Ensure excess capillary is coiled beneath the controller
case. 4. Ensure proper operation by observing the system
through one complete cycle.

CROSS REFERENCE

Some series 121371 Wells are also available without the mounting clamp. These pairs are listed together in Table 1 and in Table 7for your convenience. The cross reference in Table 8 lists wells and fittings no longer available and suggests functional replacements.

Table 7. Wells With and Without Mounting Clamp.

121371 Part Number (With Clamp)

Part Number (Less Clamp)

121371A

123869A

121371B

123870A

121371M

123871A

121371N

123871B

121371P

None

121371Q

121371L

123872A

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IMMERSION WELLS AND COMPRESSION FITTINGS

Old Part Number 121371G
121371N
122555C 122555F
122555G 123870E
123871D
123871E 123872A 104486B
138134C 138134D

Table 8. Cross Reference .

Description
Immersion well. Brass, 1/2-14 NPT, 1-1/2 in. insulation, 6-1/2 in. insertion, includes 121371 mounting clamp.
Immersion well. Copper, 3/4-14 NPT, 3 in. insulation, 3 in. insertion, includes plastic sleeve, 121371 mounting clamp.
Immersion well. Copper, 3/4-14 NPT, 4-1/2 in. insulation, 5 in. insertion.
Immersion well. Copper, 3/4-14 NPT, 4-1/2 in. insulation, 5 in. insertion, includes plastic sleeve, dual diameter bulb.
Immersion well. Copper, 3/4-14 NPT, 4-1/2 in. insulation, 5 in. insertion, dual diameter bulb.
Immersion well. Copper, 3/4-14 NPT, 1-1/2 in. insulation, 3 in. insertion, includes plastic sleeve, dual diameter capsule.
Immersion well. Copper, 3/4-14 NPT, 3 in. insulation, 3 in. insertion, includes plastic sleeve, dual diameter well.
Immersion well. Copper, 3/4-14 NPT, 3 in. insulation, 3 in. insertion, dual bulb.
Immersion well. Copper, 1/2-14 NPT, 3 in. insulation, 3 in. insertion.
Bulb compression fitting. Brass, 1/2-14 NPT.
2-1/2 in. insulation
2-1/2 in. insulation

Replacement Part Number None

Notes —

123871B

No mounting clamp.

122555B None

4-1/2 in. insulation plastic sleeve
—

None 138134E

— 2-1/4 in. insulation.

138134E

138134C

121371L

Includes mounting clamp.