Specifications

Machine Compartment Components

Starting Device Operation

The starting device is an assembly consisting of

an overload (1) and a PTC relay (2). The PTC

relay is composed of a semi conductive

substance formed in the shape of a disk (2). The

disk is connected in series with the run and start

terminals which in turn connect to the run and

start windings. The resistance of the disk

material is relatively low at room temperature.

When voltage is applied and current flows to the

compressor windings, the current flowing to the

start winding heats the disk material. As the

temperature of the disk increases, the resistance

of the disk increases rapidly and limits current

flow to the start winding. At the same time current

flow through the disk is decreasing, the effects of

current flow through the run capacitor increases.

This change in current and capacitance seen by

the start winding helps start the compressor and

allows the start winding to remain in the circuit

once the compressor is running.

Semi Conductor Disk

1. Unplug the refrigerator

2. Disconnect the starting device from the

compressor.

3. Unplug the run capacitor form the

module.

4. Connect an Ohmmeter across the L

and S terminals.

5. If the PTC is at ambient temperature,

70 – 80 degrees F., the approximate

resistance should be between 3 and 10

OHMs. An infinite reading indicates the

PTC device is open.

Checking the PTC: The easiest way to check the PTC device is to replace it

with a known good one. If a new PTC device is not available, a resistance check

can be made.

Note: Do not disassemble the PTC device. The PTC device (2) was opened to

show the interior construction and to assist in explaining the theory of operation.