Toshiba RAS-B13EKVP-E, RAS-M13EKCVP-E, RAS-M18EACV-E, RAS-M14EACV-E How To Diagnose The Trouble, 78

11. HOW TO DIAGNOSE THE TROUBLE

The pulse motor circuits are mounted to both indoor and outdoor units. Therefore, diagnose troubles according to the trouble diagnosis procedure as described below. (Refer to the check points in servicing written on the wiring diagrams attached to the indoor/outdoor units.)

Table 11-1

No.	Troubleshooting Procedure	Page
1	First Confirmation	80
2	Primary Judgment	81
3	Judgment by Flashing LED of Indoor Unit	81
4	Self-Diagnosis by Remote Controller	82
5	Judgment of Trouble by Every Symptom	85
6	How to Check Simply the Main Parts	95

Precautions when handling the new inverter (3DV Inverter)

! CAUTION: HIGH VOLTAGE

The high voltage circuit is incorporated.

Be careful to do the check service, as the electric shock may be caused in case of touching parts on the P.C. board by hand.

The new inverter (3DV inverter) will be incorporated starting with this unit.

(3DV: 3-shunt Discrete Vector control)

!The control circuitry has an uninsulated construction.

Separate potential

	G-Tr	Compressor
		Shared
Photocoupler		potential

MCU

Fan motor

FET(6in1)

Hall device

Photocoupler

IGBT x 6 Compressor

Driver Amplifier

MCU Fan motor

FET x 6

Driver

Amplifier

M18YAV-E, M18YACV-E (insulated type) EAV-E, EACV-E series (uninsulated type)

CAUTION!!

A high voltage (equivalent to the supply voltage) is also energized to ground through the sensors, PMV and other low-voltage cir- cuits. The sensor leads and other wires are covered with insulated tubes for protection. Nevertheless, care must be taken to ensure that these wires are not pinched.

CAUTION!!

Take sufficient care to avoid directly touching any of the circuit parts without first turning off the power.

CAUTION!!

At times such as when the circuit board is to be replaced, place the circuit board assembly in a vertical position.

Laying the board flat on an electrically conductive object (such as the top panel of the air conditioner's outdoor unit) while a charge is still retained by the electrolytic capacitors of the inverter's main circuit may cause short-circuiting between the electrolytic capacitors and second- ary circuit components and result in damage to the components.

Sensor leads

Do NOT lay the circuit board assembly flat.

– 78 –