BOC Edwards EXT555H, Instruction Manual

Page: 30 / 44

Issue A Jun 01
PAGE
24
EXT555H
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IN
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NC
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Remove the pump from the
system and test the ultimate
pressure of the pump alone (see
Section 3 for specification). If poor, check the pump for
contamination and if necessary
clean as described in Section 5.3.
Leak-check the pump. If the leak
rate > 10
-7
mbar l s
-1
(10
-5
Pa l s
-1
) consult BOC
Edwards or your supplier.
The EXT is very noisy or there is
excessive vibration or both. Is the pump rotational speed the
same as the resonant frequency of
the attached system? If so, change the natural frequency
of your system or isolate the pump
using flexible bellows.
Is the vibration being transmitted
from the rotary pump? If so, fit flexible bellows or a
vibration isolator in the backing
line.
Is the noise irregular and getting
progressively worse? If so, a bearing is defective. Switch
off the pump and consult Edwards
or your supplier.
Is the EXT making a constant high-
pitched noise? If so, the rotor might be out of
balance. Consult Edwards or your
supplier.
None of the above. - Consult Edwards or your supplier.
Symptom Check Action
Table 8 - Fault finding (continued)