Lennox LI009HI-230P432, Service Manual

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44
Installation and Maintenance
Service Manual
c. If Ttube ≥ 136 °F, the compressor will run at reduced frequency.
d. If Ttube ≥ 144 °F, the compressor will stop and the indoor fan will run at preset speed.
2) Heating overload
a. If Ttube ≤
126 °F, the unit will return to its original operation state.
b. If Ttube ≥ 131 °F, frequency rise is not allowed.
c. If Ttube ≥ 136 °F, the compressor will run at reduced frequency.
d. If Ttube ≥ 144 °F,the compressor will stop and the indoor fan will blow residue heat and then stop.
②
Exhaust temperature protection of compressor
If exhaust temperature ≥ 208 °F, frequency is not allowed to rise.
If exhaust temperature ≥ 217 °F, the compressor will run at reduced frequency.
If exhaust temperature ≥ 230 °F, the compressor will stop.
If exhaust temperature ≤ 194°F, the compressor has stayed at stop for at least 3 minutes, the compressor will resume itsoperation.
③
Communication fault
If the unit fails to receive correct signals for durative 3 minutes, communication fault can be justified and the whole system will stop.
④
Module protection
Under module protection mode, the compressor will stop. When the compressor remains at stop for at least 3 minutes, thecompressor will
resume its operation. If module protection occurs six times in succession, the compressor will not be startedagain.
⑤
Overload protection
If temperature sensed by the overload sensor is over 239°F, the compressor will stop and the outdoor fan will stop with atime lag of 30
seconds. If temperature is below 203°F, the overload protection will be relieved.
If voltage on the DC bus is below 150V or over 420V, the compressor will stop and the outdoor fan will stop with a timelag of 30 seconds.
When voltage on the DC bus returns to its normal value and the compressor has stayed at stop for at least3 minutes, the compressor will
resume its operation.
⑥
Faults of temperature sensors
Designation of sensors Faults
Indoor ambient temperature
The sensor is detected to be open-circuited or short-circuited for successive 5
seconds
Indoor tube temperature
The sensor is detected to be open-circuited or short-circuited for successive 5
seconds
Outdoor ambient temperature
The sensor is detected to be open-circuited or short-circuited for successive 30
seconds
Outdoor tube temperature
The sensor is detected to be open-circuited or short-circuited forsuccessive 30
seconds, and no detection is performed within 10 minutesafter defrost begins.
Exhaust
After the compressor has operated for 3 minutes, the sensor is detectedto be
open-circuited or short-circuited for successive 30 seconds.
Overload
After the compressor has operated for 3 minutes, the sensor is detectedto be
open-circuited or short-circuited for successive 30 seconds.