Mitsubishi Electric PURY-80TMU Service Handbook page 63

Symptom

3

"HO" display on re-

(Without using MELANS)

mote controller does

1) Outdoor unit address is set to "000."

not disappear and

2) Erroneous address.

ON/OFF switch is

ineffective.

3) Faulty wiring of transmission terminal block TB5 of indoor unit in the same group with remote

4) Centralized control SW2-1 of outdoor unit is turned ON.

5) Setting to interlocking system from indoor unit (Switch 3-1 = OFF), while Fresh Master is intended to

6) Disconnection or faulty wiring of indoor unit transmission line.

7) Disconnection between indoor unit M-NET transmission line terminal block (TB5) and connector

8) More than 2 sets of power supply connector (CN40) are inserted into centralized control transmis-

9) Faulty outdoor unit control circuit board.

10)Faulty indoor controller board.

11)Faulty remote controller.

(Interlocking control with MELANS)

12)No grouping registration from MELANS (Neglecting to set the relation between indoor unit and

13)Disconnection of centralized control transmission line (TB7) at outdoor unit.

14)At system connected with MELANS, power supply connector (CN40) is inserted to centralized

Checking method & countermeasure

In case MELANS is not used

Same symptom for all

units in a single refriger-

ant system?

YES

Check outdoor unit

address

51 ~ 100?

YES

Check centralized

control switch SW2-1 at

outdoor unit

ON?

NO

Faulty outdoor unit

control circuit board

In case with MELANS used

When MELANS is used, "HO" display on the remote controller will disappear at the group registration of the indoor unit and local

remote controller.

If "HO" does not disappear after the registration, check the items 12) ~ 14) in the Cause column.

1 Address setting of indoor unit to be coupled with remote controller Incorrect.

(Indoor unit = remote controller - 100.)

2 Address setting of remote controller Incorrect.

(Remote controller = indoor unit + 100.)

controller.

be used by remote controller operation (indoor unit attribute).

CN2M.

sion line of outdoor unit.

network remote controller).

control transmission line of outdoor unit.

NO

Outdoor unit

NO

address set-

ting miss

Switch setting

YES

miss

Change from

ON to OFF

Repair spot

in trouble

Cause

Address setting

miss of remote

controller

Indoor address

setting miss

Transmission line

wiring miss of in-

door unit M-NET

Check connection between indoor unit M-NET trans-

mission terminal block (TB5) and connector CN2M

Disconnection

YES

of CN2M

connector

NO

Setting miss of

Fresh Master

SW3-1

–62–

Confirm address of remote

controller with "HO" displayed

Indoor unit + 100?

Check address of

coupling indoor unit

Remote controller

-100?

YES

Check voltage of indoor unit M-

NET transmission terminal block

17 ~ 30V?

YES

Disconnection?

NO

Check Fresh Master SW3-1

ON?

YES

Faulty indoor controller board

or remote controller