Chromatography Forum

I have acquired a Shimadzu QP5000 GC/MS from my former employer. I used this instrument 10 years ago and have forgotten most of what I knew. I am trying to get the instrument up and running, but cannot get the turbo pump to start. My question is what level vacuum at the fore-pump is necessary for the turbo pump to start? The Vacuum monitor in the Vacuum Control Window says the "Lower Vacuum" is 4.2e+000 Pa. Is 4.2 Pascal sufficient, or should I be getting lower values than this? BTW I checked power to the turbo pump and there is none there, so I am thinking something is keeping it offline

I have acquired a Shimadzu QP5000 GC/MS from my former employer. I used this instrument 10 years ago and have forgotten most of what I knew. I am trying to get the instrument up and running, but cannot get the turbo pump to start. My question is what level vacuum at the fore-pump is necessary for the turbo pump to start? The Vacuum monitor in the Vacuum Control Window says the "Lower Vacuum" is 4.2e+000 Pa. Is 4.2 Pascal sufficient, or should I be getting lower values than this? BTW I checked power to the turbo pump and there is none there, so I am thinking something is keeping it offline

In GC/MS, 4.2 Pascal is about normal pressure that the foreline pump can get.

Turbo pump controller uses contact closure to start pump. Thus you can override/bypass.

Thanks, Thohry. Good to know fore-pump vacuum is ok.

Alexei, where is the contact closure that can operated manually? only manual controls are for the GC. There are none on the MS unit.

The masspec monitors for-pump vacuum and commands (via contact closure) the turbo controller to start spinning. The connections are at the back of the turbo controller. Don't recall the details, sorry.