TCM MMCUT18AS2, Service Manual

Page: 16 / 127

16
5. Electronic Function
5.1 Abbreviation
T1: Indoor ambient temperature
T2: Middle indoor heat exchanger coil
temperature
T2B: Indoor heat exchanger exhaust coil
temperature (located on the outdoor unit)
T3: Outdoor heat exchanger pipe temperature
T4: Outdoor ambient temperature
T5: Compressor discharge temperature
5.2 Electric Control Working Environment.
5.2.1 Input voltage: 230V.
5.2.2 Input power frequency:
60Hz.
5.2.3 Indoor fan standard working amp.: <1A
5.2.4 Outdoor fan standard working amp.: <1.5A.
5.2.5 Four-way valve standard amp.: <1A.
5.3 Main Protection
5.3.1 Compressor Restart Delay
---- The compressor takes 1 minute to start up the
first time. Further restarts take 3 minutes.
5.3.2 Temperature Protection of Compressor
Discharge.
When the discharge temperature of the
compressor rises, the running frequency is limited
according to the following rules:
----If 10 5
℃
( 221
℉
)
≦
T5< 110
℃
(230
℉
),
maintain the current frequency.
----If the temperature increase and T5
≧
110
℃
( 230
℉
), decrease the frequency to a lower level
every 2 minutes till to F1.
---If T5
≧
115
℃
( 239
℉
) for 10 seconds, the
compressor stops and then restart untill T5<90
℃
(194
℉
).
5.3.3 Fan Speed Malfunction
---- If outdoor fan speed is lower than 100RPM or
higher than 2400RPM for
6
0 seconds or more,
the unit stops and LED displays
E8
failure code.
5.3.4 Inverter Module Protection.
---- The inverter protection module ensures that
faults related to current, voltage, or temperature
does not damage the inverter.
If these protections are triggered, the A/C unit
stops and the LED displays the failure code.
The unit restarts 3 minutes after the protection
mechanism has turned off.
5.3.5 Low Voltage Protection
VOLTAGE
No limit
VOLT_LTM_FREQ1_ADD
VOLT_LTM_FREQ2_ADD
Note: If low voltage protection triggers and
voltage is not restored to normal within 3
minutes, the protection remains active even
after a machine restart.
5.3.6 Compressor Current Limit Protection
The temperature interval for the current limit is
the same as the range of the T4 frequency limit.
Cooling mode: