Johnson Controls T-3102 Installation And Calibration Manual

Brand: Johnson Controls

Model: T-3102

Category: Holders

Type: Installation And Calibration Manual

Johnson Controls T-3102 is a low volume output thermostat designed to modulate heating and cooling controlled devices in response to temperature changes.

Pneumatic Control Manual 717.1

Temperature Section

Technical Bulletin T-3102

Issue Date 0882

Code No. LIT-7171160X

T-3102 Heating-Cooling Deadband Thermostat

Installation and Calibration

The T-3102 is a low volume

output thermostat designed to

modulate heating and cooling

controlled devices in response to

temperature changes.

Mounting

The T-3102 can be mounted in

any position on a relatively

vibration-free surface. The

supply line must be connected to

the restricted branch of the

1/4 in. barbed tee fitting.

If a T-275-100 bulb element

holder is used to mount the

element: locate the sensitive

portion of the element in a

representative area of the air

sampling chamber. Slide the

rubber grommet on the holder

over the element past the sensing

portion. Crimp the holder slightly

to hold the element and attach

the holder to the nearest hanger.

Calibration

The T-3102 is calibrated for

4-1/2 psig and 11 psig output at

the heating and cooling set

points, respectively. This

matches the mid spring range of

typical 3 to 6 psig and 9 to

13 psig heating and cooling

valves. The 7-1/2 PSI deadband

setting falls between the spring

ranges of the two valves.

Note:

On deadband

applications which have

overlapping spring ranges, a

C-9200 or other sequencing

device should be used to bias

the cooling valve spring range to

compensate for spring range

shift.

When making calibration

changes on the T-3102, always

perform the adjustments in the

following order:

1. Deadband Adjustment

2. Cooling Set Point

3. Heating Set Point

Fig. 3: Factory Calibration Graph

Fig. 2: Bulb Element Mounting

2 T-3102 Technical Bulletin

Deadband Adjustment

1. Insert an X-200-140

hypodermic test probe with

gage into the test

connection.

2. Be sure that the temperature

at the element is above 67F.

At this point, the cooling lid is

unseated and the heating lid

is seated. If the temperature

at the element is below 67F,

the heating lid will be

unseated and inaccurate

gage readings will result.

3. Rotate the set point knob

counterclockwise until output

pressure remains constant at

approximately 7-1/2 psig.

Note the set point knob

readings.

4. Loosen the set point knob.

Remove the set point knob

and cover. Rotate the

deadband pressure regulator

screw until the desired

deadband pressure is

reached. Rotate clockwise

(CW) to increase or

counterclockwise (CCW) to

decrease the setting.

60° rotation equals

approximately a 1 PSI

change.

5. Replace the cover. Position

the set point knob over the

dials so that the readings

noted in Step 3 can be

viewed through the windows.

Tighten the set point knob in

place and turn the knob to

original factory setting.

Temperature Set Point

Adjustment

If the pressure settings of the

heating and cooling set point are

acceptable to the application, the

following instructions can be used

to change dial settings. If both

dial settings

and

pressure

settings must be changed, refer

to instructions entitled

“Temperature and Pressure Set

Point Adjustment”.

Changing Set Points with 10F°

Span Between Heating and

Cooling

To change set points while

maintaining a 10F° span between

heating and cooling, simply rotate

the set point knob CW to

decrease or CCW to increase the

set points. Both set points will

decrease or increase equally.

Changing Span Between Set

Points

1. Turn the set point dial to the

desired cooling set point.

2. Loosen the set point knob.

Remove the set point knob

and cover.

Fig. 5: T-3102 with Set Point Knob Removed

T-3102 Technical Bulletin 3

3. Rotate the heating set point

screw CW to decrease or

CCW to increase the heating

set point. Each increment

represents a 1F° change.

4. To make the set point knob

indicate the new settings,

loosen the dial set screw on

the set point dials.

5. Rotate the top (heating) dial

the same number of

increments and in the same

direction as in Step 3 above.

Tighten the set screw.

6. Replace the cover. Position

the set point knob so that the

desired heating and cooling

set points can be viewed

through the windows.

Tighten the set point knob in

place.

Temperature and Pressure

Set Point Adjustment

Note: While performing this

procedure, the temperature at the

element must be within the

operating range of the instrument.

Cooling Set Point

1. Note the temperature at the

element.

2. Turn the set point knob to the

cooling set point that matches

the temperature in Step 1.

3. Loosen and remove the set

point knob.

4. Turn the cooling output

adjusting screw to reach and

output pressure equal to the

mid spring range of the

cooling valve. Note: The

cooling output adjusting screw

is inside the post.

5. Position the set point knob so

that the temperature at the

element can be viewed

through the cooling set point

window. Tighten the set point

knob in place and turn to the

desired cooling set point.

Heating Set Point

6. With a pencil, make a mark

on the cover next to the

heating set point window.

This mark will be used later in

the procedure to reposition

the heating dial.

7. Loosen the set point knob.

Remove the set point knob

and cover. Turn the heating

adjusting screw to reach an

output equal to the mid spring

range of the heating valve.

The heating set point is now

controlling at the ambient

temperature.

8. Turn the heating adjusting

screw to the desired heating

set point. Each increment

equal 1F°. CW rotation

decreases the setting and

CCW rotation increases the

setting. Replace the cover.

9. Loosen the dial set screw

and move the top (heating)

dial to the new set point. The

new set point should be

positioned where the original

set point from Step 6 was

positioned. Tighten the dial

set screw.

10. Replace the set point knob.

The new set points can now

be viewed in the windows of

the set point knob.

Operational Checkout

1. Note the settings on the set

point knob.

2. Turn the set point knob all

the way CW. Output

pressure should rise to within

1 PSI of supply pressure.

3. Turn the set point knob all

the way CCW. Output

pressure should drop below

3 psig.

4. Turn the set point knob to the

position noted in Step 1

above. Remove the test

probe.

Repair Information

If the T-3102 fails to operate

within its specifications, and

attempts to calibrate the

instrument fail, refer to

Repair Parts R-T-3102-2 for

the appropriate repair parts.

4 T-3102 Technical Bulletin

Notes

Controls Group

507 E. Michigan Street

P.O. Box 423 Printed in U.S.A.

Milwaukee, WI 53202

Johnson Controls T-3102 Installation And Calibration Manual

Brand: Johnson Controls

Model: T-3102

Category: Holders

Type: Installation And Calibration Manual

Johnson Controls T-3102 is a low volume output thermostat designed to modulate heating and cooling controlled devices in response to temperature changes.

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Johnson Controls T-3102 Installation And Calibration Manual

Johnson Controls T-3102 Installation And Calibration Manual

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