Rough Pump Cutout

29 04 2009

So the rough pump is cutting out after about 30 minutes. I spoke with the manufacturer, and two likely causes.

  1. The rough pump is set to 240V (it will run, but will eventually cutoff from overheating)
  2. The diaphram in the rough pump is worn out, causing overheating.

My guess is #2. Investigating.

Here are the rough pumps identifiers:

Pfeiffer

Mod: MVP-035 2001/01

Mod. – Nr. PKT01200

Lab note: The chamber holds ~150  Liters (0.15 Cubic Meters or 5.2 Cubic Feet). The pumps works at 40 l/s, so it would take 3 secs to rough the chamber? Does that sound right?





Grounding the Chamber

29 04 2009

Proper grounding is really important for any electrical work, esp high voltage work. Even the ion gauge is high voltage. For now I’m just grounding to an outlet. Before we get into the really high voltage domain, I want to ground to a water pipe.

First check the outlet:

grounded

Now we fabricate a grounding strap:

grounding_strap

Make sure we don’t have any shorts to the hot leads:

short_test

Wire it up:

grounding_chamber








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