Operation
CTI-CRYOGENICS
HELIX TECHNOLOGY CORPORATION
NOTE: The use of a higher helium charge pressure for 50 HZ operation is necessary in order to compensate for the slower speed at which the compressor operates at 50 HZ. The static charge level for 60 Hz remains at
CAUTION
Exceeding the recommended system static helium charge pressure will result in the compressor and cryopump safety relief valves opening and releasing excess helium gas.
5.If the static helium charge pressure is not within the ranges as indi- cated in Table
Compressor Operation
The system may be operated once the helium charge pressure is correct.
Perform the following steps to start the compressor:
1.Set the System Circuit Breaker to the ON (UP) position.
2.Set the Control Circuit Breaker to the ON (UP) position.
3.Close all Cryopump gate valves.
4.Refer to the
5.Once the second stage temperature for all cryopumps is below 17K, record the compressor pressure gauge reading as the normal system operating pressure.
NOTE: During compressor operation, the compressor gauge reads the pressure of the gas entering the compressor prior to it being compressed.
6.Affix a copy of the data next to the compressor gauge on each com- pressor. This data is to be verified for each tool installation and whenever a configuration change is made affecting the amount of system helium gas and line volume.
The compressor pressure reading will decrease from the normal system operating pressure during cryopump regeneration or if fewer cryopumps are being operated. These are normal variations in the compressor pressure reading and should not be cause for concern.
P/N 8040540 |