Section 1. - Common Problems and Solutions
The most common field problems fall under one of the following categories:
- No Power to the unit after turning on Main Power Switch
- Unit will not Charge in Modes 3, 4, 5 or 6
- Charging Inaccuracies- Over and under charging.
- Unit will not Start Recover operation in Modes 1 and 4.
- Compressor starts, but shuts off after a few minutes of operation
- Compressor starts, but will not shut off
- High Pressure Limit Cutout
- Tank Full Limit
- Unit will not Evacuate
- Unit will not hold vacuum
- Incorrect Gauge Reading
Note: If the problem is not included in the above categories, please consult factory.
A. No power to the unit after turning on Main Power Switch
Possible Cause: Power Cord not connected correctly.
Solution: Check to make sure the Power Cord is properly plugged in a live power source and it is properly attached to the back of the unit (via IEC plug). Turn main power switch on.
Possible Cause: Circuit Breaker on the back of the unit is tripped.
Solution: Check the Circuit Breaker on the back of the unit to see if it is tripped. If tripped, push the reset switch mechanism to reset. Turn main power switch on.
Possible Cause: Electrical Malfunction- Fan is not running when Main Power Switch is turned on.
Solution: Check Main Power Switch and/or Circuit Breaker for continuity when closed. Replace defective part.
Possible Cause: Electrical Malfunction- Fan is running when Main Power Switch is turned on.
Solution: Check Transformer Fuse (F2) for continuity. Push to reset fuse. If unit is still disabled, continue with next solution
Solution: Check Transformer primary (115 or 230V) and secondary output (24V) for voltage. If primary voltage exists and there is no secondary voltage, replace transformer. If transformer is OK, continue with next solution.
Solution: Check Transformer primary (115 or 230V) and secondary output (24V) for voltage. If no primary voltage exists (make sure power is on), check for loose wires. If transformer is OK, continue with next solution.
Solution: Check Transformer primary (115 or 230V) and secondary output (24V) for voltage. If primary and secondary voltage exists, and Transformer Fuse (F2) is OK, replace PC Board. See PC Board installation instructions in Section 2.
B. Unit will not Charge
LCD Message “LOW REFRIGERANT”
Possible Cause: Not Enough Refrigerant in the Tank
Solution: The refrigerant storage tank is equipped with two valves, liquid and vapor. The unit draws in liquid refrigerant from the liquid valve on the storage tank through a dip tube which comes within ½” from the bottom of the storage tank. The AR400 series Software is programmed so that if the storage tank contains less than 2.5 lbs plus the programmed charge (mobile a/c charge amount), the unit will be prevented from charging. The message on the LCD will read LOW REFRIGERANT. Proceed with refill procedure to add more refrigerant to the storage tank.
Possible Cause: Scale needs to be Tared (re-zeroed)
Solution: If there is concern about the accuracy of the amount of refrigerant in the storage tank, please follow the directions below on how to Tare (re-zero) the scale.
See SECTION 4 Scale Tare Procedure.
LCD Message “CHECK CONNECTIONS”
Possible Cause: The R-134a High Side coupler is closed.
Solution: The AR400 series software has the ability to detect if the refrigerant is not flowing into the mobile a/c system. After 3 minutes with little or no change in the weight reading, the unit will cease the charging operation and the LCD will display a message that reads “CHECK CONNECTIONS, PUSH START”. When this message comes up (and before pushing START key), check to make sure that the R-134a high side coupler is open (turn clockwise). Push the START key to resume charging operation. If this did not correct the problem, the same LCD message will appear after another 3 minutes.
Possible Cause: The Refrigerant Storage Tank Liquid Valve is closed.
Solution: The AR400 series Software has the ability to detect if the refrigerant is not flowing into the mobile a/c system. After 3 minutes with little or no change in the weight reading, the unit will cease the charging operation and the LCD will display a message that reads “CHECK CONNECTIONS, PUSH START”. When this message comes up and before pushing START key, check to make sure that the storage tank liquid and vapor valves are opened (turn counter-clockwise). Push the START key to resume charging operation. If this did not correct the problem, the same LCD message will appear after another 3 minutes.
Possible Cause: High and/or Low Side Service valves are not depressing R-12 mobile a/c Schrader core.
Solution: Adjust the Schrader core depressor on the end of the High and Low Service hoses. Pull out the core depressor to ensure that it will fully depress the Schrader core on the mobile a/c system service port.
Possible Cause: The Liquid and Vapor hoses are switched- Initial operation of the unit.
Solution: The AR400 series Software has the ability to detect if the refrigerant is not flowing into the mobile a/c system. After 3 minutes with little or no change in the weight reading, the unit will cease the charging operation and the LCD will display a message that reads “CHECK CONNECTIONS, PUSH START”. When this message comes up and before pushing START key, check to make sure that the storage tank liquid and vapor hoses go to the corresponding storage tank liquid and vapor ports. NOTE: Always define the liquid and vapor ports according to what is written on the valve handles. DO NOT go by colors. Once the tank hose connections are verified, push the START key to resume charging operation. If this did not correct the problem, the same LCD message will appear after another 3 minutes.
Possible Cause: Charging Solenoid Valve is not functioning.
Solution: The AR400 series Software has the ability to detect if the refrigerant is not flowing into the mobile a/c system. After 3 minutes with little or no change in the weight reading, the unit will cease the charging operation and the LCD will display a message that reads “CHECK CONNECTIONS, PUSH START”. Disconnect power to the unit. Danger: Only a qualified service technician should service this equipment. An Electrical Shock hazard is present. It will be necessary to operate this unit with the front cover opened. Please use extreme caution when live power is applied to the unit. Open the front cover of the unit to expose the internal components.
Find SV3 (SV3-12 for R-12 circuit or SV3-134 for R-134 circuit).
Pull both wires off SV3 to expose the ¼ male tabs. Using an electrical multi-meter, check the resistance reading of the
solenoid coil. For the 115 50/60 coil, the resistance will be 410-460 ohms and for the 230 50/60 coil, the resistance will be 1400-1500 ohms. If no resistance is registered, replace coil. If coil is OK, then proceed to check voltage output on SV3. Reinstall SV3 wires. Run the AR400 in the Mode 3. Apply the multi-meter between the two terminals on SV3. When the unit LCD displays “CHARGING”, read the multi-meter to see if voltage is present between the two SV3 terminals.
If no voltage is present, turn power off to the unit. Proceed to check relays R2 and R7 for proper operation. See relay repair in Part 2 for further details. If voltage is present, proceed to solenoid valve repair section in Part 2 for further details.
Possible Cause: Scale needs to be tared (re-zeroed)
Solution: The AR400 series Software has the ability to detect if the refrigerant is not flowing into the mobile a/c system. After 3 minutes with little or no change in the weight reading, the unit will cease the charging operation and the LCD will display a message that reads “CHECK CONNECTIONS, PUSH START”. Turn off power to the unit. If the Tare set point of the scale is incorrect, this could “fool” the PC Board into thinking that there is more refrigerant in the storage tank than what there really is, thus the charge would start would be very slow. See SECTION 4 Scale Tare Procedure.
C. Charging Inaccuracies- Over and Under Charging
Possible Cause: Unit was moved during the Charging operation
Solution: It is very important that when in Mode 3, 4, 5, or 6 that the unit is not bumped during the CHARGING CYCLE or put in an area where vibration will affect the scale reading. The pneumatic wheels will help to reduce an external vibration. Also one of the front casters utilizes a brake to help further stabilize the unit.
On the start up of the CHARGING CYCLE, the AR400 series software actually delays the scale reading for about 5 seconds until the unit’s compressor vibration subsides (except MODE 6).
Possible Cause: Storage Tank touching Framework
Solution: Place the Storage tank in the center of the scale platform. If the scale touches the framework, it will cause enough friction that the scale will read incorrectly.
Possible Cause: Uneven surface
Solution: The AR400 Series unit should not be operated on a surface with a grade of more than 5 degrees. The unit should be placed on a level surface to ensure the highest accuracy of charging.
Possible Cause: SV3 Charging Solenoid is not properly closing.
Solution: Remove SV3 and check for foreign material in the solenoid valve. See SECTION 2 on solenoid valve service.
D. Compressor will not start in the Recover Cycle operation (Mode 1, 4, and 7)
Compressor will not start -Refrigerant pressure on Manifold gauges
-RECOVER COMPLETE on LCD
Possible Cause: High and/or Low Side Manifold valves not open.
Solution: Open High and Low Side Manifold valves to allow refrigerant to reset Low Pressure Switch. Restart Unit.
Possible Cause: Electrical Malfunction
Solution: Turn the AR400 series unit on. Apply 25 psig pressure to the Low Side Service hose. Open both the Low Side Service and Low Side Manifold valves. If the RECOVER COMPLETE message does not change to RECOVERING, check the Low Pressure Switch. Verify that the Low Pressure Switch is “seeing” this applied pressure. See Section 2 for Low Pressure Switch replacement details.
Compressor will not start -Refrigerant pressure on Manifold gauges.
-LCD message RECOVERING
.
Possible Cause: Electrical Malfunction
Solution: Danger: Only a qualified service technician should service this equipment. An Electrical Shock hazard is present. It will be necessary to operate this unit with the front cover opened. Please use extreme caution when live power is applied to the unit. Check the compressor power leads to see if voltage exists (Start the unit in the Mode 1). If voltage exists, turn off and disconnect power. Next, check for continuity across the compressor external overload.
If continuity across the overload exists, check the resistance compressor run and start windings.
The resistance readings for the 115-volt compressor will is: Main Winding 1.5 ohms Aux Winding 5.8 ohms
The resistance readings for the 230-volt compressor will is: Main Winding 5.4 ohms Aux Winding 19.8 ohms
If either the main or the auxiliary compressor windings are open (infinite resistance), replace compressor as per SECTION 2 in this manual.
If voltage does not exist on the compressor power leads, check Relay R1 and R7. Also check for loose wires. See SECTION 2 for additional Relay information.
If continuity does not exist on across the compressor external overlay, replace the overload.
- Recover starts, but shuts off after a few minutes of operation and there is still refrigerant in the mobile a/c system. The LCD message RECOVER COMPLETE is displayed and the Low and High Side gauges are in a vacuum.
Possible Cause: High and/or Low Side Service valves not open.
Solution: Open High and Low Side Service valves to allow refrigerant to reset Low Pressure Switch. Restart Recovery Mode.
Possible Cause: High and/or Low Side Service valves are not depressing R-12 mobile a/c Schrader core.
Solution: Adjust the Schrader core depressor on the end of the High and Low Service hoses. Pull out the core depressor to ensure that it will fully depressor the Schrader core on the mobile a/c system service port.
F. Compressor starts (in Mode 1 and 4) but does not shut off.
Manifold gauges pull down to zero, but do not pull into a vacuum
Possible Cause: Oil Injection Valve left open.
Solution: Close Oil Injection Valve. Check NCG level in the storage tank.
Possible Cause: Leak in Service Hoses
Solution: Because the Service Hoses are constantly being used to connect the AR400 to a mobile a/c system, leaks might development where the Service Hose connects to the unit or between the Couplings and the service hose. Periodically inspect the Service hoses. Replace if necessary. If a leak is found, check the NCG level in the storage tank. The service hoses can be isolated from the unit by closing the Manifold valves. If the Green Light energizes after the Manifold valves are closed, the Service hoses would be the source of the leak.
Possible Cause: Mechanical leak somewhere on the low side of the unit.
Solution: Pressurize the Red and Blue service hoses. Open the Low and High Side Manifold valves. Start the unit in the RECOVER mode for 15 seconds. This will allow refrigerant to pressurize the compressor. Use a leak detector to find leak. Check all connections from the compressor suction port back to the Manifold. Fix leak.
Manifold gauges show pressure and do not drop
Possible Cause: Check Valve (CV1) installed into the solenoid block assembly is stuck shut.
Solution: Remove Check Valve and check for foreign materials. If check valve is defective, replace. See SECTION 2 on check valve service.
Possible Cause: SV1 Vacuum Solenoid is not opening.
Solution: Check continuity of SV1 solenoid coil. If OK, remove SV1 and check for foreign material in the solenoid valve. See SECTION 2 on solenoid valve service.
G. High Pressure Limit Cutout - LCD message HIGH PRESS LIMIT
Possible Cause: Tank Vapor valve closed causing the High Pressure switch to Open.
Solution: Open tank Vapor valve to relieve the high pressure restriction. Push the reset button on the back of the unit. Re-start unit in the desired mode.
Possible Cause: High amounts of non-condensable (NCG’s) are present in the storage tank
Solution: Check the tank pressure. If large amounts of NCG’s are present in the storage tank, follow the purge procedure in the manual to remove the NCG’s.
Possible Cause: Electrical Malfunction
Solution: Check for loose wires.
Solution: Check Relays R6 and R8. See Section 2 for Relay information
Solution: Check continuity of High Pressure switch. Should be normally closed.
H. Tank Full Limit - LCD message “TANK FULL”
Possible Cause: Storage tank has exceeded maximum refrigerant amount.
Solution: You will need a spare empty storage tank. Connect the High Side Service hose to the vapor port of the empty storage tank. Charge about 8-10 pounds of refrigerant into the empty storage tank. Properly label the empty storage tank with the refrigerant type. The unit can now be used for normal service operation.
Possible Cause: Scale not reading correct weight.
Solution: If the Tare set point of the scale is incorrect, this could “fool” the PC Board into thinking that there is more refrigerant in the storage tank than there really is. This could make the refrigerant reading in the tank exceed the maximum amount. Follow the Tare procedure in SECTION 3 of this manual.
I. Vacuum Pump will not start in Mode 2.
Vacuum Pump will not start -Refrigerant pressure on Manifold gauges
Possible Cause: Low Pressure Switch is not activated (closed position)
Solution: Run the Recover Mode first to activate the Low Pressure Switch.
Vacuum Pump will not start -Vacuum Pressure on Manifold gauges
Possible Cause: Vacuum Pump power switch is in the OFF position or the Vacuum Pump power cord is not plugged into the vacuum pump receptacle.
Solution: Make sure vacuum pump power switch (on the rear of the vacuum pump) is always in the ON position. Also make sure the vacuum pump power cord is plugged into the receptacle.
Possible Cause: Electrical Malfunction
Solution: Check Relays R2 and R7. Also check the SV2 and Vacuum Pump receptacle.
J. Vacuum Pump starts in Evacuation Cycle, but will not pull into a deep vacuum