User Guide

ManualsBrandsBarber Colman ManualsHVAC Replacement PartsSPDT Thermostat w/ Coil (50-90F)

Figure-14 Typical Cooling Application for Two Stage Units.

CHECKOUT

After installing a thermostat, make an initial check of the

switching action. Verify the switch action by listening to the

switch contacts.

1. Turn the setpoint dial to a temperature above ambient.

This should cause the thermostat to switch, making orange

to brown.

2. Turn the setpoint dial setting down gradually. Orange to

brown must break, making orange to red.

3. Compare the differential of the device to the differential

shown on the performance charts by turning the dial. The

differential of the device is the difference in dial reading

between the make of orange to brown and the make of

orange to red on single switch units.

ADJUSTMENTS

Setpoint

Screwdriver adjustment. Scales dual marked °F on front and

°C on back. To change scale, remove spring retaining ring,

select scale and replace retaining ring.

Differential

The differential is adjustable by turning the adjustor located on

the side of the device (see Figure-15).

Figure-15 Adjustments.

Single Stage: Each line represents approximately 3°F (2°C)

change.

Two Stage: Each notch represents approximately 2°F (1°C)

change between stages. (Differential per switch is fixed.)

To adjust interstage differential:

1. Disconnect power to unit.

2. Remove cover.

3. Turn adjustor to approximately desired position.

4. Check out by turning dial and noting dial readings where

switch contacts make.

5. After changing interstage differential, recalibrate. See

CALIBRATION.

CALIBRATION

1. With all power disconnected, soak bulb(s) for 10 minutes

at known temperature (must be 70°F for dual bulb).

2. Turn dial and note where switch contacts make.

3. Turn dial midway between click points.

4. Turn the calibration nut (located under dial) until the

temperature of the bulb is indicated on the dial (see

Figure-15).

Note:

On two stage units follow above procedure. LO switch

is first stage on cooling applications. HI switch is first stage

on heating applications.

MAINTENANCE

Regular maintenance of the total system is needed to assure

sustained optimum performance. Thermostats should be

periodically inspected for dirt or blockage of air over the

elements.

REPAIR

Field repair is not recommended. Replace defective device.

Incr. Spread

Calibration Nut

(Turn with 1/2"

open end wrench)

Differential Adjustment