ENVIRONMENTAL TEST CHAMBER TROUBLESHOOTING

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Troubleshooting AES humidity test chambers.


In this video we discuss common troubleshooting issues related to humidity control and water sourcing of humidity test chambers. We cover resetting the steam generator, inspecting the humidity heater, changing the demineralizer cartridge and water sourcing best practice.

My demineralizer cartridge needs to be replaced.


In this video we show you how to identify when your demineralizer cartridge needs to be replaced. We then demonstrate the quick process of replacing the cartridge. Following this easy maintenance tip will limit down time and prevent future humidity testing headaches.

Starting up and operating my salt spray test chamber.


In this video we will show you how to start up and operate MX series salt spray test chambers. We cover basic operating principals, start up procedure and temperature adjustment.

The compressor(s) will not start.

When my unit is connected to a suitable electrical system, the compressor and condenser fan are not connecting.

Check these possible causes and solutions:
  1. A blown fuse in the main line or in the compressor circuit
  2. → Locate the source of the overload and replace the fuse.
  3. A defective refrigeration switch.
  4. → Replace the defective switch.
  5. The refrigeration circuit has a defective power relay.
  6. → Replace the defective part with an equivalent relay.
  7. The off/on, high/low or pressure (if equipped) has cutout.
  8. → To fix this, push the button on the individual controls to reset. Also, check the cause of the pressure cutout.

When my unit is connected to a suitable electrical system, the condenser fan is operating but the compressor is not.

Check these possible causes and solutions:
  1. Low line voltage or your system is attempting to operate on inadequate wiring.
  2. → If your voltage is low, install a booster transformer. If low voltage occurs only when other loads draw excessively, try connecting the unit to another line which is not overloaded.
  3. The compressor is off due to an internal overload.
  4. → Examine the compressor to verify proper voltage supply.
  5. There is an open circuit in wiring to the compressor.
  6. → Locate the open circuit and repair.
  7. The compressor(s) current relay is defective or there is an internal thermal overload.
  8. → Replace the defective part.
  9. The compressor is defective.
  10. → Replace the compressor.

My test chamber now has a slow pull down or no pull down at all.

When my compressor and condenser fan run continuously and the compressor amperage is normal.

Check these possible causes and solutions:
  1. Your test chamber's evaporator coil has iced up.
  2. → Defrost and dry out your test chamber. Remember to plug up ports or any openings where external air can enter the chamber.
  3. There is an excessive live load in the test chamber or there is excessive heat leakage into the chamber through the ports or other openings is occurring.
  4. → Eliminate the cause.
  5. The door is being opened too often.
  6. → Eliminate the cause.
  7. There is a leak and consequent loss of refrigerant charge.
  8. → Identify and repair the leak. Then recharge the test chamber with refrigerant.
  9. The compressor is defective
  10. → Replace the defective compressor.
  11. A test piece of specimen is blocking the airflow in the test chamber.
  12. → Remove any excess load or relocate the specimen.

On compressor overload, the compressor cycles on and off.

Check these possible causes and solutions:
  1. The condenser is dirty, which is restricting the airflow.
  2. → Clean the condenser or move the test chamber so that there is free airflow across the condenser and out the side of the chamber.
  3. The ambient temperature in the room is too high.
  4. → Make sure that the test chamber is located in a well ventilated area where the temperature is normal.
  5. The condenser fan is not operating correctly.
  6. → Try tightening the fan blade. Replace the motor or repair as necessary.
  7. The condenser fan is not running or operating at the rated RPM.
  8. → Repair or replace the condenser fan motor.
  9. The temperature controller set point is out of adjustment.
  10. → Use your test chamber's instruction manual to correct the adjustment.
  11. The refrigerant line is damaged or restricted.
  12. → Identify any damage or restriction and correct it.
  13. The test chamber is running on low voltage or worn relay contacts.
  14. → Correct the low volume condition and/or replace the relay.

On low temperature cutout, the compressor cycles on and off.

Check these possible causes and solutions:
  1. The test chamber's temperature is too low to permit running mechanical refrigeration.
  2. → Increase the temperature inside the test chamber above +10°F.
  3. The low temperature cutout control is defective or out of adjustment.
  4. → Adjust, replace, or repair the low temperature cutout control.

The test chamber does not maintain a continuous low temperature.

My compressor runs continuously or will not always run when it is required by the temperature controller. Check these possible causes and solutions:
  1. The condenser is dirty, which is restricting the airflow.
  2. → Clean the condenser or move the test chamber so that there is free airflow across the condenser and out the side of the test chamber.
  3. The ambient temperature in the room is too high.
  4. → Make sure that the test chamber is located in a well ventilated area where the temperature is normal.
  5. The condenser fan is not operating correctly.
  6. → Try tightening the fan blade. Replace the motor or repair as necessary.
  7. The line voltage is too low.
  8. → Install a booster transformer. Or, if low voltage occurs only when other loads draw excessively, try connecting the test chamber to another line that is not overloaded.
  9. The temperature controller is defective.
  10. → Repair or replace the temperature controller.
  11. There is a defective compressor(s) current relay or an internal thermal overload.
  12. → Analyze and identify the specific cause and take appropriate action.
  13. The compressor is stopping on its internal overload.
  14. → Examine the overload and system pressure.

My test chamber does not have a temperature pull up.

This occurs when there is no power to the heater.

Check these possible causes and solutions:
  1. The test chamber has no power.
  2. → Check the fuse or circuit breaker for the line.
  3. The temperature controller is defective.
  4. → Replace the defective controller.
  5. The heat switch is defective.
  6. → Replace the defective heat switch.
  7. The relay is defective. This occurs only with models that have relays.
  8. → Replace the defective relay.
  9. The heater connection is loose or the heater is defective.
  10. → Check the connection to the heater. Or replace defective heater.
  11. The heat link is open.
  12. → Replace the heat link. Do not attempt to repair it and do not short out the heat link.

This occurs when there is power to the heater.

Check these possible causes and solutions:
  1. The heater connection is broken.
  2. → Fix the connection.
  3. The heater has burned out.
  4. → Replace the burned out heater.

My test chamber's temperature pull up is above the controller set point.

The control is satisfactory however is at incorrect temperature.

  1. Check this possible cause and solution:
  2. The temperature controller may be out of calibration.
  3. → Calibrate the temperature controller.

The heater is energized continuously. This may result in damage to the test chamber and its contents.

Check these possible causes and solutions
  1. The temperature controller of the unit is defective.
  2. → Replace the defective controller.
  3. The relay is defective. This occurs only with models that have relays.
  4. → Replace the defective relay.
  5. The heater has shorted to ground.
  6. → Determine ground and correct.

Unknown and unwanted vibrations and/or noises are coming from the test chamber.

This occurs when the circulation fan motor is running rough.

Check these possible causes and solutions:
  1. The unit's fan blade is unbalanced or damaged.
  2. → Add balance weights or replace damaged fan blade.
  3. The fan motor shaft has bent.
  4. → Replace the fan motor and blade.
  5. The fan shaft is rubbing or the fan blade is hitting.
  6. → Center the fan motor and provide sufficient running clearance for the fan blade.
  7. The fan motor bracket is loose.
  8. → Tighten the motor mounting screws.
  9. There is moisture on the fan blade.
  10. → Heat up the test chamber.
  11. CO2 "snow" is on the fan blade.
  12. → Heat up the test chamber.

There is poor air circulation within the test chamber.

The motor is not developing at full speed.

Check these possible causes and solutions
  1. The motor is attempting to run on low voltage.
  2. → Remove excessive load from the line or use a booster transformer.
  3. The shaft is dragging on insulation in the test chamber wall.
  4. → Turn the shaft by hand until the shaft provides its own clearance. Insulation can sometimes shift during shipment.

The test chamber's fan blade is loose.

Check these possible causes and solutions
  1. The fan blade is hitting.
  2. → Tighten the set screw securely and provide sufficient running clearance for the fan blade.

The device under test (DUT) is too large or is obstructing the airflow.

Check these possible causes and solutions
  1. The area is too small for the application or DUT is too large or is improperly inserted.
  2. → Begin by rearranging the DUT. If the problem persists, you need a larger area in which to test this device.

The interior surfaces are corroded.

There is apparent rusting of stainless interior.

Check these possible causes and solutions
  1. Corrosion may be caused by: an improper cleaning procedure, testing of corrosive materials, a device under test, or from rust deposited from ferrous material of test fixtures,
    → Wash the test chamber's interior regularly with mild soap, particularly following any exposure to acid or other highly corrosive compounds. Do not clean with steel wool or permit ferrous materials to rub on stainless surfaces. If you do, particles or iron will be imbedded in the stainless surface and cause rust. Gummy deposits, if allowed to remain, may result in electrolytic action and pitting.

'Snow' or dry ice crystals are building up in the test chamber. This occurs only if an optional CO2 system is installed.

This occurs only when operating below -100°F. Some snow is always present in the range of -75°F to -100°F but it sublimes as rapidly as it forms and does not accumulate sufficiently to be objectionable.

Check these possible causes and solutions
  1. The temperature controller is out of calibration.
  2. → Calibrate the temperature controller.