Excess Air In Tank

^ Do not shortcut the pre-programmed, 15 minute vacuum pump cycle. Short cutting does not allow the ACR4 automatic air purge circuit to fully expel the air in the ACR4 tank. Short cutting will eventually lead to illumination of the tank "excess air" light on the PureGuard 2.

^ The quick connect valves on the ACR4 red and blue service hoses must be closed (rotated outward) when they are attached to the storage fittings on the ACR4. Open valves will allow excess air to enter the storage tank during certain ACR4 operating modes.

^ The Active Flow Control adds additional hose and line fittings. These connection points are areas for possible leaks. Pliers should be used to tighten all ACR4 fittings and periodic checks should be made to assure none have loosened. Loose fittings can cause refrigerant loss or excess air in the storage tank. Be careful not to over torque and destroy fittings.

^ High levels of excess air are not quickly purged out of the Recovery Recharging Station tank. It could take 1 week of purging 4 times per day before the red "excess air" light turns off. You must have patience.

Using the following procedure to manually open and close the air purge valve in the ACR4 can accelerate removal of high levels of excess air. This is most effective if done first thing in the morning before the refrigerant is agitated by any vehicle recovery, vacuum or recycling procedures.

1. With the ACR4 powered up, on the control panel, press "shift" and "enter" keys simultaneously. Screen will go blank.

2. Press "shift" and "charge" keys simultaneously. "D2" will display on screen.

3. Press "1" key. "01" will display and purge valve solenoid will click. Excess air will be vented from the tank but this procedure does not vent any refrigerant to atmosphere. The auto purge mechanism will close an internal valve when the air content reaches a minimal level.

Press "shift" key to exit the manual air purge mode.

Tank pressure can be measured using the high side manifold gauge in the ACR4 by shifting to the charge mode, setting a charge weight of 0.50 lb and pressing the "enter" key, then pressing the "charge" key. The ACR4 valves will open and fill the lines with refrigerant at tank pressure. With the high side gauge valve on the control panel open, read the pressure immediately for an accurate pressure measurement because as the refrigerant begins to cool in the lines, the pressure will decrease. At an ambient room temperature of 70°F (21°C), the pressure in a tank of R134A with no air will be between 70 and 80 psi. The correlation between pressure and temperature is approximately 1 psi for every 1 degree increase.