HELIX CTI-CRYOGENICS CRYO-TORR 100 Installation, Operation And Servicing Instructions page 23

)
)
4.6 Connecting Power Cables
ACAUTION
1. The switch(s) on the front of the conlIoller or
compressor must be in the OFF position before
making any and all electrical connections.
2. Do not connect the conlIoller or compressor
to
its power source until all connections have been
made between the components of the high-
vacuum pump system.
1. Check to insure the following electrical cables
are properly connected between the conlIoller
and the compressor: (8300 Compressor only)
a. The compressor conlIol cable between the
conlIoller and compressor.
b. The compressor power cable.
2. Check to insure the cold-head power cable is
properly connected to the cold head.
3. Check to insure the conlIoller or compressor main
power cable
is
properly connected
to
the main
power source.
4. Your system is now ready
to
operate.
4.7 Multi-Cryopump Installation
Using 8300 Compressor
For Your Information--
Contact the CTI-Application Engineering Department
for specific hardware and gas pressure requirements
before installing your multiple cryopumps and
8300 Compressor. If you have installed your cryo-
pumps and desire to establish the static pressure for
your system refer
to
procedures in this section.
4-3
en-CRYOGENICS
HELIX TECHNOLOGY CORPORATION
To establish the appropriate gas charge pressure of a
multiple (2) cryopump (CT-lOO) and 8300 Compressor
installation using interconnecting lines totaling more
than 10 feet (on either the supply or return side) proceed
as follows:
1. Connect the multiple cryopump system as shown
on Figure 4.1. This figure depicts a typical multi-
cryopump installation with an 8300 Compressor
and 8002 ConlIoller. Note that the cable is connected
from the conlIoller to each cold head; also, the
components are helium connected in parallel (all
supply fittings piped together).
2. Check the static charge of the system and add or
discharge helium gas as required to bring the
static pressure
to
245-250 psig (1690-1725 kPa).
(Follow the procedures as descirbed in Section 7.4
to add helium or procedures in Section 4.5 to dis-
charge helium).
3. Start the system.
4. Approximately 10 minutes after start-up, note the
pressure on the return gauge on the helium com-
pressor. Adjust the pressure by adding or discharg-
ing helium to 85-95 psig (585-655 kPa).
5. Allow the system to run until both cryopumps have
attained a temperature less than 20K.
6. Again adjust the pressure as in step 4 above, until
the return gauge in the compressor is reading
105-115 psig (725-780 kPa).
7. Shut off the system and allow it to reach room
temperature (approximately 3 hours without
regeneration). Note the static pressure in the
system. It should not exceed 255 psig (1755 kPa).
This then becomes the static pressure of your
multiple cryopump installation.