Installation and Commissioning Guide
Classic 2 Outdoor Units
Installation and Commissioning Guide - Classic 2 Split Ducted Outdoor Unit
Doc. No.0525-073 Ver. 8 210414
45
Checking for Superheat:
Maintaining the correct superheat is important for ensuring the evaporator is achieving maximum capacity and avoiding
excessive liquid refrigerant returning to the compressor.
1. From the R-410A Pressure/Temperature Chart record the corresponding Saturated Suction Temperature (
SST
) at
the given suction pressure.
2. Calculate the system super heat using the formula below:
Superheat = SLT -SST
3. If superheat is within the range (see charging table below), there is no need to add/remove refrigerant.
• If superheat is lower than minimum, it means that liquid refrigerant may be returning to compressor. It is
necessary to remove refrigerant.
• If superheat is higher than maximum, it means that refrigeration capability of evaporator is not fully maximised. It
is necessary to add refrigerant charge.
Allow the systems to stabilise (15 - 30 mins) and repeat the steps 1-3 until superheat falls within the range specified in the
table below.
Cooling
Heating
Subcooling
Superheat
Subcooling
Superheat
4 - 8
2 - 8
10 - 14
2 - 8
NOTES
The above subcooling and superheat recommendations are based on the following rated conditions:
• Cooling: 35
0
C DB outdoor, air entering indoor at 27
0
C DB / 19
0
C WB.
• Heating: 7
0
C DB / 6
0
C WB outdoor, air entering indoor at 20
0
C DB Nominal indoor airflow.
