Main Protection - North American HVAC MSC-28CRDN1-MN15W Service Manual

frequency.
8.2.2 LED display control function.
Pressing "LED display" button on remote controller will turn off all displays on indoor unit, while
pressing once again, all displays will resume.

8.3 Main Protection

8.3.1 Three Minutes Delay at restart for compressor.
---- 1 minute delay for the 1st time start-up and 3 minutes delay for others.
8.3.2 Temperature protection of compressor top.
---- Top temp. protector cut off for 30s and restart the compressor with 3 minutes delay.
8.3.3 Temperature protection of compressor discharge.
----When the compressor discharge temp. is getting higher, the running frequency will be limited as
below rules:
----Compressor discharge temp. T5>115℃ for 5s, compressor stops.
---- 108<T5<115℃, decrease the frequency to the lower level every 3 minutes.
-----90<T5<105℃, keep running at the current frequency.
-----T5<90℃, no limit for frequency.
8.3.4 Fan Speed is out of control.
----When Indoor Fan Speed keeps too low or too high for certain time, the unit will stop and the LED
will display the failure
8.3.5 Inverter module Protection.
----The Inverter module itself has a protection function against current, voltage and temperature. If
these protections happen, the corresponding code will display on indoor unit.
8.3.6 Indoor fan delayed open function
----When the system starts up, the louver will be active immediately and the indoor fan will open 10s
later.
8.3.7 Compressor preheating functions.
----Preheating permitting condition:
If T4(outdoor ambient temperature)＜3℃ and the machine connects to power supply newly or if T4＜3℃
and compressor has stopped for over 3 hours, the compressor heating cable will work.
----Preheating mode:
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