PROCEDURE LETTER

K

L

R -8580

TEST PROCEDURES

(CONT’D)

\

 

COMPONENT TEST

CONVECTION HEATER TEST

Make sure the convection heater is fully cooled and test as follows;

a. Disconnect wire leads and measure the resistance with an ohmmeter. On the R x 1 scale, the resistance between the convection heater terminals should be approximately 38 ohms.

b. Disconnect wire leads and measure the insulation resistance with 500V - IOOM R insulation resistance meter.

The insulation resistance between convection heater terminal and cavity should be more than 0.5M R.

THERMISTOR TEST

Disconnect connector-E from the control unit. Measure the resistance of the thermistor with an ohmmeter. Connect the ohmmeter leads to Pin No’s E-3 and E-4.

Room Temp.

Resistance

20 “C- 30 “C

Approx. 350 n - 155 S2

If the meter does not indicate above resistance, replace the thermistor.

DAMPER MOTOR TEST

When the power cord is plugged into the wall receptacle, and 240 volts A.C. is supplied to the damper motor the motor operates until the damper is opened and the damper switch closes. Then the damper motor stops operation.

If the damper motor does not operate, check for input voltage by A.C. volt-meter at the motor.

1.Disconnect the power cord from the wall receptacle.

2.Disconnect the wire leads of motor and connect the meter leads to the wire leads of main wire harness.

3.Reconnect the power cord into the wall receptacle.

If 240 volts A.C. is indicated at the wire leads, replace the motor.

Not indicated, check the wire harness and the relay unit.

(RD82EOl U)

M

DAMPER SWITCH TEST

Disconnect the wire leads from the switch terminals and connect ohmmeter leads to the common (COM) and normally open (NO) terminals of the switch.

1.When switch actuator is pushed by the damper motor cam, the meter should indicate a closed circuit.

2.When the power cord is plugged into the wall receptacle, the damper motor operates and damper cam starts to rotate.

The switch actuator is released the meter should indicate an open circuit. If improper operation is indicated, replace the damper switch.

(RD82702U)

17

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Sharp r-8580 manual Procedure Letter, Thermistor Test, Damper Motor Test, Damper Switch Test