Test Operation Of Indoor Unit - Toshiba MMD-AP0726HP-UL Service Manual

8-3. Test operation of indoor unit

Check function for operation of indoor unit (Functions at indoor unit side)
This function is provided to check the operation of the indoor unit singly without communication with the
remote control or the outdoor unit. This function can be used regardless of operation or stop of the system.
However, if using this function for a long time, a trouble of the equipment may be caused. Limit using this
function within several minutes.
[How to operate]
1) Short-circuit CHK pin (CN71 on the indoor P.C. board) (MCC-1643) .
The operation mode differs according to the indoor unit status in that time.
Normal time: Both float SW and fan motor are normal.
Abnormal time: Either one of float SW or fan motor is abnormal.
2) Restricted to the normal time, if short-circuiting DISP pin (CN72 on the indoor P.C. board ( MCC-1643)) in
addition to short-circuit of CHK pin (CN71 on the indoor P.C. board), the minimum opening degree (30 pls) can
be set to the indoor PMV only.
When open DISP pin, the maximum opening degree (1500 pls) can be obtained again.
[How to clear]
Open CHK pin. While the system is operating, it stops once but automatically returns to operation after
several minutes.
Fan motor
Indoor PMV (*)
Communication
P.C. board LED (MCC-1643)
• To exchange the indoor PMV coil, set the indoor PMV to Max. opening degree.
• For the detailed positions of CHK pin (CN71 on indoor P.C. board) and DISP pin (CN72 on indoor P.C. board),
refer to the indoor P.C. board (MCC-1643).
Normal time
DISP pin open
(H)
Max. opening degree (1500 pls) Min. opening degree (30 pls)
All ignored
Lights
Short-circuit of CHK pin
DISP pin short circuit
(H)
All ignored
Lights
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Abnormal time
Stop
Min. opening degree (30 pls)
All ignored
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