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Warning, Component testing – Friedrich HAZARDGARG R-410A User Manual

Page 12

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FAN MOTOR

SWITCH, ON-OFF

Line side

SOLID STATE

RELAY

Load

side

LED indicates

contacts closed

when lit

FAN MOTOR

A 230 volt single phase permanent split capacitor motor

is used to drive the evaporator blower and condenser

fan. A running capacitor is wired across the start and run

terminals of the motor.

The motor is totally enclosed and is protected with a line

volt-age overload located internally of the motor. The

motor shaft is stainless steel to resist corrosion.

FAN MOTOR – TEST

1. Determine that the capacitor is good.

2. Perform continuity test on windings to determine if

open, shorted or okay.

SOLID STATE RELAY

Two 50 amp rated 208/230 volt solid state relays are used

to energize the compressor and fan motor. Terminals 3

and 4 are the 208/230 volt line side. Terminals 1 and 2

are load side contacts.

SYSTEM CONTROL SWITCH

This switch is double pole, single throw. Check for

continuity between terminals 2 and 3, and 5 and 6.

COMPONeNT TeSTING

CAPACITORS

Many motor capacitors are internally fused. Shorting the

terminals will blow the fuse, ruining the capacitor. A 20,000

ohm 2 watt resistor can be used to discharge capacitors

safely. Remove wires from capacitor and place resistor

across terminals. When checking a dual capacitor with

a capacitor analyzer or ohmmeter, both sides must be

tested.

Capacitor

Check

with

Capacitor

Analyzer

The capacitor analyzer will show whether the capacitor

is “open” or “shorted.” It will tell whether the capacitor

is within its micro farads rating and it will show whether

the capacitor is operating at the proper power-factor

percentage. The instrument will automatically discharge

the capacitor when the test switch is released.

Capacitor Connections

The starting winding of a motor can be damaged by a

shorted and grounded running capacitor. This damage

usually can be avoided by proper connection of the

running capacitor terminals.

From the supply line on a typical 230 volt circuit, a 115 volt

potential exists from the “R” terminal to ground through a

possible short in the capacitor. However, from the “S” or

start terminal, a much higher potential, possibly as high as

400 volts, exists because of the counter EMF generated

in the start winding. Therefore, the possibility of capacitor

failure is much greater when the identified terminal is

connected to the “S” or start terminal. The identified

terminal should always be connected to the supply line, or

“R” terminal, never to the “S” terminal.

When connected properly, a shorted or grounded running

capacitor will result in a direct short to ground from the “R”

terminal and will blow the line fuse. The motor protector will

protect the main winding from excessive temperature.

ELECTRIC SHOCK HAZARD

WARNING

Turn off electric power before servicing.

Discharge capacitor with a 20,000 Ohm 2 Watt

resistor before handling.

Failure to do so may result in personal injury,

or death.

ELECTRIC SHOCK HAZARD

WARNING

Disconnect power to the unit before

servicing. Failure to follow this warning

could result in serious injury or death.

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