Varian 4000 GC, Hardware Operation Manual

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Checking Cooling Fans
CAUTION
To prevent overheating, do not block air intakes.
The cooling fans maintain an optimal temperature for the turbomolecular pump
and the other electronics modules. Without the cooling fans, the lifetime of the
turbomolecular pump and temperature-sensitive PC-board components can be
shortened. To ensure proper operation of the cooling system, operate the MS
with its covers in place. In addition, be sure to check the fans at least once each
week. The MS is equipped with two fans on its rear panel. The function of these
fans is to pull air into the instrument. To check fan operation proceed as follows:
1. Make sure that the main power switch and service switch are turned ON.
2. Place a large sheet of paper over one of the fan guards.
a. If the paper is sucked toward the fan guard, the fan is working.
b. If the paper is not sucked toward the fan guard, the fan is broken.
Contact your Varian Customer Support Representative to arrange for a
replacement.
3. Check the second fan in the same manner. If the fans are excessively noisy,
e.g., if they whine or whir, one of the fans may be about to fail and it should
be replaced.
4.
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