Johnson Controls A99B Series Catalog Page

FANs 125, 121, 930, 930.5 Product/Technical Bulletin A99 Issue Date 0615

A99B Series Temperature Sensors

The A99B Series Temperature Sensors are passive PTC (Positive Temperature Coefficient) sensors. The A99B sensors are splashproof and are designed to measure temperature in a variety of refrigeration applications. Several accessories allow easy tailoring of the temperature sensor to various mounting configurations.

Applications include temperature sensing for freezers and coolers, as well as in defrost termination sensing, space and return air temperature sensing, and condenser fan cycling.

Figure 1: A99B Temperature Sensors

Features and Benefits

 Variety of Lead Lengths Encompasses most application requirements

and simplifies wiring sensors

 Assortment of Mounting

Hardware Available

 Very Accurate Sensing

Element

 Stainless Steel Sensor Bulb Allows use in more applications than other

Provides configuration for many applications—customizable

Provides excellent performance in a wide variety of control applications

types of bulbs; no corrosion

pplication Overview

IMPORTANT: All A99B Series Sensors are

designed for use only with operating controls. Where an operating control failure would result in personal injury and/or loss of property, it is the responsibility of the installer to add devices (safety, limit controls) or systems (alarm, supervisory) that protect against, or warn of, control failure.

The A99B temperature sensor line offers an economical solution for a wide variety of temperature sensing needs in refrigeration and HVAC applications. Typical temperature sensing applications and environments include:

Sensor

To Controller

Figure 2: 4-Sensor Averaging Wiring

SensorSensorSensor

 freezers  display cases  walk-in coolers  reach-in coolers  defrost termination temperature sensing  condenser fan cycling  space and return air temperature sensing  outdoor air sensing  process cooling and heating

ensor Temperature Averaging

Multiple sensors may be wired in a series parallel arrangement to provide an average temperature reading in an area when one sensor cannot provide a representative temperature reading. This can be accomplished with 4, 9, 16, etc., (2

, 32, 42, etc.)

sensors. In a series parallel arrangement, there must always

be the same number of parallel-connected sensors as there are series connected sensors. In Figures 2-4, each parallel leg is represented as a column of sensors and each series leg as a row of sensors.

Sensor Sensor Sensor

SensorSensorSensor

To Controller

Figure 3: 9-Sensor Averaging Wiring

Sensor

Senso

Sensor

Senso

Sensor

Senso

Sensor

Senso

Sensor

2 A99B Series Temperature Sensors Product/Technical Bulletin

To Controller

Figure 4: 16-Sensor Averaging Wiring

imensions

1/4 (6)

2 (50)

Figure 5: A99B Sensor, in. (mm)

Accessories

A99B series accessories include the following:

1 1 1/16

9 1/8 (229)

4 5/16

(110)

1/4 (6)

Surface M ount Clip

1/2

(13)

(25.4)

A99-CLP-1

Sun Shield SHL10A-603R

ADP11A-600R

(25.4)

EMT Conduit Adapter

1 3/4 (44)

4 3/4 (119)

7/8

(23)

Figure 6: Available Accessories, in. (mm)

(42)

4 1/2

(113.5)

PVC Enclosure BOX10A-600R

(76)

1 3/8

(35)

Dia. 3/8

(9.3)

peration

The A99B sensor incorporates a PTC silicon sensing element whose resistance increases with an increase in temperature. The sensor has a reference resistance of 1,035 ohms at 77F (25C). Each element is calibrated according to a standard graph, as shown in Table 2.

The A99B series sensors are typically used with Johnson Controls/PENN System 450™ controls, MR Defrost controls, MS Multi-Stage controls, and A421 Electronic Temperature Controls.

The A99B sensors can also be used with Johnson Controls System 27 NOVA; A255 fan speed control modules; and R78, DX-9100, XP-9102, XPA-4x1, System 350™ controls, A419 Electronic Temperature controls, and XPA-8x1 products.

ounting

Mounting Considerations

The A99B sensor may be mounted in virtually any position. To ensure proper operation of the A99B Series sensors, observe the following guidelines:

 Mount sensors in areas where they are exposed to

representative temperature conditions and sufficient air mixing. Avoid mounting the sensors where air stratification exists.

 Avoid areas subject to excessive mechanical

vibration or electrical noise.

 For outdoor applications, avoid areas where the

sensor will be exposed to direct sunlight because this causes the sensor to read a higher temperature. The north side of the building is preferred for outdoor sensors. If not possible, install a sun shield.

 Use a thermally conductive paste where appropriate

to improve the thermal contact with the sensor.

 Do not subject silicon cable (A99BC) to any

silicon-based fluids, as this will degrade the cable.

A99B Series Temperature Sensors Product/Technical Bulletin 3

Mounting Using an Immersion Well

1. Select the mounting location in the pipe line. A 1/2 in., 14 NPT, opening is required to properly install the immersion well (WEL11A601R). The pipe’s diameter must be greater than the length of the well probe.

2. Insert an appropriate amount of thermally conductive paste in the well.

3. Install the immersion well. Tighten hex nut securely using a wrench.

Tighten

with Wrench

1/2 inch 14 NP T

Opening

Mounting with a PVC Enclosure

The PVC enclosure can be mounted in a variety of ways. See Figure 6 for mounting dimensions. When mounting the PVC enclosure, refer to the Mounting Considerations section, as well as the following:

 To minimize false readings caused by air movement

through the conduit hole, seal that part of the enclosure after the sensor has been inserted.

 If a conduit connection is required, snap the conduit

adapter into the bottom opening of the enclosure and tighten the adapter’s set screw.

1. Loosen the two PVC enclosure screws and remove the front plate.

Sensor Clip

Front Plate

PVC Enclosure Screws

Figure 7: Installing the Immersion Well

4. Using a straight slot screwdriver, loosen the set screw at top of the immersion well.

5. Thread the spring, then the bushing, onto the sensor lead.

Figure 8: Insert Sensor, Spring, and Bushing

6. Insert sensor, spring, and bushing into well, so that at least one-half of the bushing is inserted into the well, as shown in Figure 8 (bushing will compress spring).

7. Tighten the set screw against the bushing.

Senso

Figure 9: PVC Enclosure

2. Thread the sensor through the bottom opening and snap the sensor in the sensor clip inside the PVC enclosure.

3. Replace the front plate on the PVC enclosure and firmly tighten the screws.

4 A99B Series Temperature Sensors Product/Technical Bulletin

iring

WARNING: Shock Hazard. Disconnect all

power to the controller that the sensor is connected to before wiring or servicing.

For wiring, follow the instructions below:  Make sure all wiring conforms to the National

Electric Code and local regulations.

 Run high and low voltage wiring in separate

conduits. For applications in critical industrial environments, use a sensor with a shielded cable (A99BA).

 If wire is added to the sensor leads, additional

resistance may affect the sensor reading. Longer wires increase resistance, which causes a shift in the sensor temperature reading.

Note: At the wire lengths listed in Table 1, the

error in the sensed temperature is less than 1F (0.5C).

Table 1: Maximum Sensor Wire Lengths (for less than 1°F error)

Wire Gauge Wire Length

AWG Feet Meters

14 AWG

16 AWG)

18 AWG 20 AWG 22 AWG

800 244 500 152 310 94 200 61 124 38

heckout Procedure

Before applying power, make sure installation and wiring connections are according to job specifications. After necessary adjustments and electrical connections have been made, operate the system and observe at least three complete cycles before leaving the installation.

roubleshooting

Check the sensor for proper resistance:

1. Disconnect the sensor from the control.

2. Take a temperature reading at the sensor location. Be sure to let the thermometer stabilize before taking a reading.

3. Use the temperature reading from Step 2 to determine the expected sensor resistance from Table 2.

4. Using an ohmmeter, measure the actual resistance across the two sensor leads.

5. Compare the expected resistance to the actual resistance.

6. If the sensor's actual resistance deviates substantially from the expected resistance found in Table 2, replace the sensor.

 Shielded Cable Models (A99BA) Only: For all

controls, including the Johnson Controls/PENN System 350, MR, MS, and A419, connect the sensor cable shield to the controller per the controller’s instructions.

A99B Series Temperature Sensors Product/Technical Bulletin 5

° (C

260 240 220 200 180 160 140 120 100

80 60 40

Temperature (°F)

-20

-40 500 700 900 1100 1300 1500 1700 1900 2100

Resistance in Ohms

Figure 10: Resistance Scale for

Fahrenheit Temperatures

120 100

80 60 40 20

T emp er at u re (°C )

-20

-40 500 700 900 1100 1300 1500 1700 1900 2100

Resistance in Ohms

Table 2: Resistance vs. Temperature

°F (°C) Resistance

in Ohms

-40 (-40) 613 113 (45) 1195

-31 (-35) 640 122 (50) 1237

-22 (-30) 668 131 (55) 1279

-13 (-25) 697 140 (60) 1323

-4 (-20) 727 149 (65) 1368 5 (-15) 758 158 (70) 1413

14 (-10) 789 167 (75) 1459

23 (-5) 822 176 (80) 1506

32 (0) 855 185 (85) 1554

41 (5) 889 194 (90) 1602 50 (10) 924 203 (95) 1652 59 (15) 960 212 (100) 1702 68 (20) 997 221 (105) 1753 77 (25) 1035 230 (110) 1804 86 (30) 1074 239 (115) 1856 95 (35) 1113 248 (120) 1908

104 (40) 1153

Sensor accuracy is within 0.9F° (0.5C°) between 5 and 167°F (-15 and 75°C). Tolerance increases at temperatures outside this range, as shown in Figure 12.

°F (°C) Resistance

in Ohms

Figure 11: Resistance Scale for

Celsius Temperatures

)

ominal

-0.9 (-0.50)

om f o

-1.8 (-1.00)

-2.7 (-1.50)

2.7 (1.50)

1.8 (1.00)

0.9 (0.50)

0.00

-40 (-40)

-4 (-20)

32 (0)

68 (20)

(40)

(60)

140

104

Temperature °F (°C)

Figure 12: Sensor Accuracy

176 (80)

212 (100)

248 (120)

6 A99B Series Temperature Sensors Product/Technical Bulletin

epairs and Replacement

Field repairs or calibration must not be made. For replacement sensors, contact your nearest Johnson Controls/PENN representative.

rdering Information

Table 3: Sensors

Product

Code Number

A99BA-200C A99BB-25C A99BB-200C A99BB-200D

A99BB-300C A99BB-500C A99BB-600C A99BC-25C

A99BC-300C

A99BC-1500C

PTC Silicon Sensor with Shielded Cable; Cable length 6-1/2 ft (2 m); Range: -40 to 212°F (-40 to 100°C) PTC Silicon Sensor with PVC Cable; Cable length 9-3/4 in. (0.25 m); Range: -40 to 212°F (-40 to 100°C) PTC Silicon Sensor with PVC Cable; Cable length 6-1/2 ft (2 m); Range: -40 to 212°F (-40 to 100°C) PTC Silicon Sensor with PVC Cable Bulk Pack; contains 100 A99BB-200 sensors.

Individual sensor cable length 6-1/2 ft (2 m); Range: -40 to 212°F (-40 to 100°C) PTC Silicon Sensor with PVC Cable; Cable length 9-3/4 ft (3 m); Range: -40 to 212°F (-40 to 100°C) PTC Silicon Sensor with PVC Cable; Cable length 16-3/8 ft (5 m); Range: -40 to 212°F (-40 to 100°C) PTC Silicon Sensor with PVC Cable; Cable length 19-1/2 ft (6 m); Range: -40 to 212°F (-40 to 100°C) PTC Silicon Sensor with High Temperature Silicon Cable

Cable length 9-3/4 in. (0.25 m); Range: -40 to 248°F (-40 to 120°C) PTC Silicon Sensor with High Temperature Silicon Cable

Cable length 9-3/4 ft (3 m); Range: -40 to 248°F (-40 to 120°C) PTC Silicon Sensor with High Temperature Silicon Cable

Cable length 49 ft (15 m); Range: -40 to 248°F (-40 to 120°C)

When contacting the supplier, state the model number of the sensor. The sensor model is printed on the yellow label wrapped around the sensor cable.

Description

Table 4: Accessories (See Figure 6 for illustration of accessories.)

Product

Code Number

A99-CLP-1 ADP11A-600R BOX10A-600R SHL10A-603R WEL11A-601R

Surface Mounting Clip for the A99B Temperature Sensor 1/2 in. diameter EMT Conduit Adapter (box of 10) for use with BOX10A-600R PVC Enclosure Sun Shield Immersion Well

A99B Series Temperature Sensors Product/Technical Bulletin 7

Description

pecifications

Product A99B Series Silicon Temperature Sensors

Sensing Range Model A99BA and A99BB: -40 to 212F (-40 to 100C)

Model A99BC: -40 to 248F (-40 to 120C)

Reference Resistance 1,035 ohms at 77F (25C)

Accuracy 0.9°F (0.5°C) between 5 and 167°F (-15 and 75°C). See Figure 12 for accuracy outside of

this range.

Sensor Construction Probe: Stainless Steel

Sensor Lead Wire

Insulation

Lead Wire Gauge 22 AWG

Ambient Operating

Conditions

Ambient Storage

Conditions

Shipping Weight 1.4 oz (41 g) for 6 1/2 ft (2 m) sensor

Accessories

Model A99BA: Shielded PVC Cable Model A99BB: PVC Cable Model A99BC: High Temperature Silicon Cable

Model A99BA and A99BB: -40 to 212°F (-40 to 100°C); 0 to 100% RH, Condensing Model A99BC: -40 to 248°F (-40 to 120°C); 0 to 100% RH, Condensing

Model A99BA and A99BB: -40 to 221°F (-40 to 105°C); 0 to 100% RH, Condensing Model A99BC: -40 to 266°F (-40 to 130°C); 0 to 100% RH, Condensing

See Table 4.

The performance specifications are nominal and conform to acceptable industry standards. For application at conditions beyond these specifications, consult Johnson Controls/Penn Application Engineering at (414) 274-5535. Johnson Controls, Inc. shall not be liable for damages resulting from misapplication or misuse of its products.

Controls Group 507 E. Michigan Street P.O. Box 423 www.johnsoncontrols.com Milwaukee, WI 53201 Printed in U.S.A.

8 A99B Series Temperature Sensors Product/Technical Bulletin

Johnson Controls A99B Series Catalog Page

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