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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
controller 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).
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) in addition to
short-circuit of CHK pin (CN71 on the indoor P.C. board), the minimum opening degree (30pls) can be
set to the indoor PMV only.
When open DISP pin, the maximum opening degree (1500pls) 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 (
∗
)
Louver
Drain pump
Communication
P.C. board LED
Short-circuit of CHK pin
Normal time
Abnormal time
DISP pin open
DISP pin short circuit
(H)
(H)
Stop
Max. opening degree (1500pls)
Min. opening degree (30pls)
Min. opening degree (30pls)
Horizontal
Horizontal
Immediate stop
ON
ON
ON
All ignored
All ignored
All ignored
Lights
Lights
Flashes
• 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-1
643.
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Summary of Contents for Carrier MMU-AP0074HPUL
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