Section B Electric Components - Sunbeam 20060328 Service Manual

LINE VOLTAGE
It is essential to know the line voltage in the refrigerator. A voltage reading should be taken at the compressor start and
during its operation. The line voltage should not fluctuate more or less than 10% with respect to the nominal. A low
voltage overheats the compressor motor windings resulting into the compressor cycling for thermal overload or impeding
the compressor starting.
The most common reasons for low voltage in the refrigerator are the wrong diameter feed cables and the overloaded
lines.
GROUNDING
All refrigerators have an electric supply cable adapted to each country rules, as well as a ground line installed in the
electric system as a protection against electric discharges.
Each electric component and metallic part must be grounded. Some components like the defrosting timers can have
"double isolation", and need no ground wire.
Make sure the wall plug is the country standard and is adequately grounded according to the rules in force.
RELAY AND OVERLOAD PROTECTOR
Magnetic Relay
The start relay in the compressor is the pushbutton type for the compressor's starting (S) and run (R) terminals, as
shown in Figure B1.
The relay coil conducts the main current of the winding. The relay armature maintains the winding start contacts in open
position except during the starting period.
At starting, when the thermostat closes the electric circuit, an electric current passes through the main motor winding and
the relay coil. This activates such coil and lifts the relay armature, allowing the start winding contacts closure.
The current through the starting winding introduces a second out phased magnetic field in the stator and starts the motor.
While the motor speed increases, the main winding current is reduced.
SECTION B – ELECTRIC COMPONENTS
Compressor terminals
Start winding
Relay
Overload
protector
Figure B1 – Terminal plugs, relay and overload protector
Run winding
PAGE. B1