Operation Modes And Functions; Abbreviation; Safety Features; Sensor Redundancy And Automatic Shutoff - York YEFE BZTM-MOW1 Series Service Manual

1. Operation Modes and Functions

1.1

Abbreviation

Unit element abbreviations
Abbreviation Element
T1 Indoor room temperature
T2 Coil temperature of evaporator
T3 Coil temperature of condenser
T4 Outdoor ambient temperature
TS Set temperature
1.2

Safety Features

Compressor Three-minute Delay at Restart
Compressor functions are delayed for up to one minute upon the first startup of the unit, and are delayed for up
to three minutes upon subsequent unit restarts.
Phase Check Function(for 3 phase models)
If the phase sequence is detected wrong or lack of 1 or 2 phase, the unit won't start and there is error code displayed on
outdoor PCB.
Low Pressure Check Function(for 48k and 60k models)
The low pressure switch should be always closed. If it is open, the system will stop until the fault is cleared. During
defrosting procedure , 4 minutes after defrosting ends and 5 minutes after compressor is on in heating mode, low
pressure switch won't be checked.
Note: The system will not check if the protection could be cleared in 30 seconds after the protection occurs. If this
protection occurs 3 times, it won't recover automatically until the main power is cut off.
Over-current Protection
When compressor is running, if the current is over twice of the rated for 3 seconds, the compressor will stop and an error
code will be displayed on the outdoor PCB. If the current becomes normal, the compressor will restart after 3 minutes.
Note: The current won't be checked within 3 seconds after the compressor starts. The system will not check if the
protection could be cleared in 30 seconds after the protection occurs.

Sensor redundancy and automatic shutoff

• If any one of temperature sensor malfunctions, the air conditioner displays the corresponding error code and ceases
operation.
Refrigerant leakage detection
This function is active only when cooling mode is selected. It will detect if the compressor is being damaged by
refrigerant leakage or by compressor overload. This is measured using the coil temperature of evaporator T2 when the
compressor is in operation.
1.3 Display Function
Unit display functions
Ceiling&floor
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