SK00-4802-DI-002-04
No.16.10.20
25
(1) Do not turn on the power to the heater with no supply of cooling
water.
Turning on the power to the heater without supplying cooling water
may cause damage to the pump as follows:
1. A break is caused in a heater cable.
2. Solder on the cooling water piping dissolves and falls.
3. Parts, such as the pump case and the jet, are damaged.
4. Oil is consumed or degraded faster, or burned.
5. Oil scatters to the high vacuum section, contaminating the
chamber etc.
(2) Be sure to supply a specified amount of cooling water and install
an interlock that activates when the flow rate becomes insufficient.
No supply of cooling water may cause damage to the pump or
remaining water in the pump to evaporate to increase the pressure
in the cooling system, causing high temperature steam to spout.
(1) Do not turn on the power to the heater if the inside of the pump is at
a pressure of 1 to 3 × 10
3
Pa (a few Torr) or higher.
Oil is oxidized, making a low ultimate pressure unable to reach.
(2) If an amount of gas equal to or higher than the maximum
throughput is fed through the pump or if the auxiliary pressure
becomes higher than the critical back pressure, the pump stops
evacuation.
Under this condition, oil may spout scattering to the inlet and outlet
ports, contaminating the oil in the high vacuum system above the
pump.
(3) If oil heated during the operation is exposed to the atmosphere (in
the event of an inflow of a large amount of air due to an accident
etc.), the oil is oxidized and decomposed, which degrades the
ultimate pressure of the pump.
Take great care during the operation that this kind of accident does
not occur.
If it occurs, it is necessary to immediately close the valve on the air
inlet side to exhaust the air introduced to the inside of the pump.
If the exposure time to the atmosphere is within a few minutes, the
pump recovers to the original state after operation for a few hours
in many
cases but, in the worst case, the oil must be replaced.
For replacement of oil, see Section 3.2 Oil filling.
CAUTION
CAUTION
