FAQ
Cryopump Trouble Items
1. When the compressor is started, the valve motor does not start.
2. The valve motor whines but does not start.
3. The valve motor rotates but does not cool down.
4. The housing of the cryopump generates condensation or is abnormally cold.
5. Loud pounding noise does not go away even after about 15 minutes of operation.
7. The temperature changes periodically.
8. The refrigerating capacity deteriorates rapidly, and the performance of cryopump deteriorates.
10. Are there any standards for the cooling water quality used for the helium compressor?
1. When the compressor is started, the valve motor does not start.
Probable cause: The communication line between the valve motor and compressor unit is not connected.
Action: Stop the compressor and connect the communication line.
Probable cause: Failure of the valve motor.
Action: Check the valve motor.
Probable cause: The communication line is disconnected.
Action: Check the continuity of each line.
2. The valve motor whines but does not start.
Probable cause: Failure of the condenser or resistance.
Action: Check each of the parts.
Probable cause: Failure of the valve motor.
Action: Check the valve motor.
Probable cause: The communication line is disconnected.
Actions: Check the continuity of each line.
3. The valve motor rotates but does not cool down.
Probable cause: Insufficient vacuum insulation.
Action: Check the rough vacuum pumping system and leakage.
Probable cause: Poor connection state of the gas connection hose.
Action: Check if the connection hose is connected correctly for high and low pressure.
Probable cause: The operating pressure of the compressor unit is abnormal.
Action: Check the pressure.
4. The housing of the cryopump generates condensation or is abnormally cold.
Probable cause: Insufficient vacuum insulation.
Action: Check the rough vacuum pumping system and leakage.
Probable cause: The accumulated gas is released again, by naturally leaving the unit after it stopped.
Action: Perform the rough vacuum.
5. Loud pounding noise does not go away even after about 15 minutes of operation.
Probable cause: Abnormal pressure in the compressor unit.
Action: Check the pressure in the compressor unit.
Probable cause: Gas is contaminated.
Action: Clean the pump and refill the gas.
Probable cause: Abnormal circulation of the orifice valve.
Action: Contact the person in charge of service.
6. Operates Continuously
Probable cause: The compressor repeats the operation and stops.
Action: Check the compressor unit.
7. The temperature changes periodically.
Probable cause: Due to contaminated gas, freezing and melting of the impurities in the displacer is being repeated.
Action: Clean the pump and refill.
8. The refrigerating capacity deteriorates rapidly, and the performance of cryopump deteriorates.
Probable cause: The vacuum insulation is torn.
Action: Check for leakage of the rough vacuum pumping system.
Probable cause: Malfunction of the compressor.
Action: Check the compressor unit.
Probable cause: Defective valve motor, resistance or condenser.
Action: Perform an electrical check.
9. The refrigerating capacity deteriorates gradually, and the performance of cryopump also deteriorates gradually.
Probable cause: A small leak occurred in the vacuum insulation.
Action: Perform a leak test.
Probable cause: The seal material has worn out.
Action: When the expander is properly disassembled, black particles can be seen near the leaking seals. Replace the seals.
Probable cause: A leak has occurred in the expander.
Action: Perform a leak check and repair the leaking part.
Probable cause: Inappropriate circulation of the orifice valve.
Action: Contact your supplier.
10. Are there any standards for the cooling water quality used for the helium compressor?
In order to maintain stable operation of the product, it is important to control the quality of the cooling water as well as to control the amount and temperature of the cooling water. The "Water Quality Guidelines for Air Conditioning Systems" established by the Japan Refrigeration and Air Conditioning Industry Association is generally used as a standard for the cooling water quality. Therefore this standard is applied to this product.
Water Quality Standards
| Items PH | Cooling Water | Tendency | |||
| Transient or Circulating Cooling Water Systems |
Cooling Tower Supply Water |
Corrosion | Scale Formation | ||
| Standard Value | PH（25℃） | ※16.5-8.0 | ※16.0-8.0 | ○ | ○ |
| Conductivity (25℃ uS/cm) | 800 or less | 200 or less | ○ | ||
| M alkali level (PPM) | 100 or less | 50 or less | ○ | ||
| Total hardness (PPM) | 200 or less | 50 or less | ○ | ||
| Chlorine ion (PPM) | 200 or less | less | ○ | ||
| Sulfuric acid ion (PPM) | 200 or less | 50 or less | ○ | ||
| Iron (PPM) | 1.0 or less | 0.3 or less | ○ | ○ | |
| Sulfuric ion (PPM) | Not detected | Not detected | ○ | ||
| Ammonium ion (PPM) | 1.0 or less | 0.2 or less | ○ | ||
| Ionized Silica (PPM) | 50 or less | 30 or less | ○ | ||
| Isolated carbonic acid (PPM) | ※2 | ※2 | ○ | ||
*1. Only the PH value of the cooling tower supply water indicates 6.0–8.0 . This value is set taking into consideration that there will be no problems because the PH value will increase while the circulation system is used in the tower, even though the PH value decreases temporarily caused by the carbon dioxide gas dissolving in the ground water.
*2. Although the quantitative acceptable value is not defined, it is clear that this item will act as a corrosion factor.
