to add to Pauls comments,

I don't know about changing them every year, as they are supposed to have a
3 year life span, but certainly it is wise to check them from time to time
and to change them within 3 years as they don't cost much at all. We got
ours from a local supplier for $20US equivalent as well. We found that
after changing the fans and turbo's the noise level in the lab has dropped
from 70db to 50db, so a major improvement in comfort!

Again, your turbo lifespan really depends on roughing pump maintenance,
changing the oil every 6 months, installing foreline traps, and not
overworking the turbo's on jobs that the rotary's should be doing.

cheers

Karyne

At 11:51 19/02/02 -0800, you wrote:
>I would like to second Karyne's  idea below of replacing the cooling fans
>on the EXT 70's.  I have had an EXT 70 begin to whine badly and then
>discovered that the cooling fan was broken.  I now replace the cooling fans
>every year when I change the pump oil.  The fans were available from a
>local supplier in the right size and voltage for just US$20 each; much
>cheaper than from Edwards.
>
>Paul Brooks.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dr Karyne Rogers
Stable Isotope Laboratory Team Leader
Institute of Geological and Nuclear Sciences
PO Box 31-312
Lower Hutt
New Zealand

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