GMW GMW7022 PDF

Introduction

Note: Nothing in this standard supercedes applicable laws and regulations.

Note: In the event of conflict between the English and domestic language, the English language shall take precedence.

Purpose. The purpose of this test is to determine the refrigerant charge for air conditioning systems for either front only evaporator systems, front and rear evaporator systems, and/or systems with evaporators and refrigerant chillers. A correct refrigerant charge (this test) shall be determined before testing system performance including heat exchanger core freeze (GMW15775), city traffic A/C (GMW3202) and steady state A/C (GMW3037).

Applicability. This procedure applies to all passenger vehicles and light commercial trucks with an Air Conditioning (A/C) system.

Remarks

The Thermostatic Expansion Valve (TXV) setting may impact the test result, therefore the TXV setting shall be determined prior to testing or this procedure must be repeated for confirmation after the final TXV setting is selected. Special operation modes such as fast charging of battery electric vehicles requires consideration of receiver drier size, as noted in 4.1.4.

Pressure measurements in this standard are Kilopascals Gauge Pressure (kPaG). It is permissible to collect data using measurement of Kilopascals Absolute (kPaA). Use care to avoid conversion error, and label clearly in databases and engineering reports if using kPaA units. Temperature differential measurements (differences between two individual temperature measurement locations) are noted in degrees Kelvin (°K) to avoid confusion with single temperature measurements noted in degrees Celsius (°C).