The jury is out on this great and pertinent survey Dr. Pino put out on social media (most people are voting for leaving the vacuum and electronics on which probably is the best bet, but not everyone can do that).
If you are going the shutdown route, I worked for the US government for several years in my career. I've got loads of experience with shutdowns!
Disclaimer: Always talk to your vendor and local FSE. Do not take the advice of some weirdo on the internet about your instrument that was hundreds of thousands or millions of dollars. Duh.
First of all -- please dig that instrument manual out. Wait. Scratch that. Use the newest instrument manual! I bet your vendor's website has the newest one. If you're Q Exactive user, it'll look like this.
Way better front page than the one you've probably got a hard copy of. Manuals seriously do evolve. I've been told to do things that I know was not in the manual and found out I just had an old one and the way the old one said to do it was wrong. True stories!
Follow the manual. It's boring, but super important.
Big thing I always forget: It is very extremely common for the gas line solenoids to default to open rather than closed when you shut off the main power. If you're on gas cylinders or liquid dewars, you won't be the next day....
If you're on house N2 and it's limitless, you can keep venting it forever, I guess.
There are big words on every single page of this PDF that warn me not to share it without the explicit permission of the authors, so here it is!
That really cool slide deck that neither of us know where you got it from is great despite being a few years older. Not everything that is old is bad. Just...almost...everything. If you go to the end there is lots about doing a PM and the oil part is super critical if you're being powered down.
According to this surprisingly interesting Leybold (they make some of the vacuum pumps you're familiar with) course material on "Fundamentals of Vacuum Technology"...
When you're constantly pulling a vacuum and the pumps are hot you are venting the moisture that might come into your instrument. It's not much and that's why the oil last for 6 months to a year depending on pump and oil. When it is sitting, you can pick up some moisture.
This may be completely wrong, but this is what we'd do after a prolonged shutdown for Congress and whoever to agree to whatever.
1) Visually examine the oil for signs of any partitioning or oil/water layers. If you see anything, dump that oil the fuck out and replace with the vendor recommended oil.
2) Pump down the instrument and bake out.
3) In the very near future -- in Baltimore summers, 1 week max, rest of the time, maybe 2 weeks, shut it all down again and change out the pump oil. Water in the pump reduces the roughing pump capabilities. And you know where that extra pumping power has to come from -- the turbos.
Change the oil in my roughing pumps more often than strictly necessary, or stress my turbo more?
Disclaimer Repeat: Always talk to your vendor and local FSE. Do not take the advice of some weirdo on the internet about anything, in particular, your instrument that was hundreds of thousands or millions of dollars. Duh.
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