NT150/360 Problem

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Tom McCarthy
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NT150/360 Problem

Post by Tom McCarthy » Fri Mar 30, 2018 12:07 pm

I tried running my turbopump again today after a hiatus of a couple of months.

When I started the turbopump (press "Start" on the controller) it started accelerating, and then hit normal operation. Soon after hitting normal operation, the red failure light lit up and I pressed stop on the controller, shut off the backing pump and let some air in via the foreline to slow things down. I gave the pump a few minutes and pumped down again. On reaching 20 microns again, I turned the controller on. This time after the controller turns on and is finished self-testing, the failure light is lit up, without starting the turbo at all. Disconnecting the controller from mains power and connecting again results in the same.

It's a Leybold Oerlikon TMP 150, with a NT 150/360 controller. The pump was serviced and certified fine by Leybold last year, and has not been used since, same for the controller.

Backing pressure was 20 microns or so. Backing pump is an Edwards RV3, I've posted about both before. Leaks are negligible, it takes over 3 minutes to go from 20 to 40 microns when the valve on the roughing pump is shut.

John Futter seems to be a fan of the TMP pumps, but is not so fond of their NT controllers - Any ideas John?
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Richard Hull
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Re: NT150/360 Problem

Post by Richard Hull » Fri Mar 30, 2018 6:25 pm

Just curious... Is that pump spec'd to run in the horizontal position?

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Tom McCarthy
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Re: NT150/360 Problem

Post by Tom McCarthy » Fri Mar 30, 2018 6:42 pm

Yeah, Leybold give the go-ahead for horizontal operation. That's not the bug unfortunately.

From the manual:
In most applications the TURBOVAC will be flanged direct to the high-vacuum
flange for the system. The design of the lubricating system makes it
possible to mount and run the TURBOVAC in any desired attitude. It is not
necessary to support the pump.

Jerry Biehler
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Re: NT150/360 Problem

Post by Jerry Biehler » Sat Mar 31, 2018 3:08 am

Do NOT let air in the foreline to slow it down. Some pumps have a orifice on a solenoid that can be opened at around half speed. This is not one of them.

Probably something in the controller died. It is a pretty old model so the caps could be going south. You can call olerikon and talk to them and maybe they will send you a schematic like they did for my NT50 and then you can start chasing down the fault. Call them. Don't email them.

But a warning, these drives are not isolated from the mains so all your test equipment will need to be or you need to put the drive on an isolation transformer.

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Re: NT150/360 Problem

Post by John Futter » Sun Apr 01, 2018 1:15 am

been away a few days
I have a full manual for that controller but as jerry says it is very old
there is a newer controller bigger in size that runs all these pumps from your one up to the tp1000C
can nhot rmrmber the part # will look at work after Easter as we have three of thesec all off ebay.

Check the cable that controller uses a couple of the wires to look at the pump for an internal resistor that tells it whether it is a 150 or 300 l/s version
(differnt speeds and accel ramp) a borken wire in the cable will bring up the fault light
but it sounds like the half bridge output stage has a shorted TO3 trnasistor in it

Tom McCarthy
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Re: NT150/360 Problem

Post by Tom McCarthy » Mon Apr 02, 2018 7:48 pm

Thanks for calling that Jerry, what would you do when wanting to slow down the pump then - wait it out? There's no real speed feedback on the controller, but the manual says it's able to start the pump even if it's still rotating, maybe I don't need to slow the pump down.

John, will be waiting to hear back from you. Cable, pump and controller were all provided by a reputable and generous vacuum business here in Ireland https://www.provac.ie/ and pump was working previously so cable was okay too.

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Re: NT150/360 Problem

Post by Jerry Biehler » Tue Apr 03, 2018 12:59 am

You wait. Pumps can be restarted it will apply a bit of power and look at the back emf and determine the speed and start ramping up from there.

Waiting a few minutes is better than letting in too much air and turning your pump into a bunch of shredded aluminum foil. It's also hell on the bearings.

I would call up the supplier. They might be able to help, maybe they have another drive around you could at least borrow to narrow the problem down to the pump or drive.

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Re: NT150/360 Problem

Post by Tom McCarthy » Tue Apr 03, 2018 4:37 pm

Suppliers are going taking a look at it and see what they can do, sent it off today.

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Re: NT150/360 Problem

Post by John Futter » Wed Apr 04, 2018 7:19 pm

Tom
Start looking for a NT20 controller a much later controller for most of the leybold pumps

heres the manual for it
turbotronik_nt20_1.pdf
(345.76 KiB) Downloaded 20 times

Tom McCarthy
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Re: NT150/360 Problem

Post by Tom McCarthy » Mon Apr 30, 2018 12:32 pm

Vacuum company fixed the controller thankfully. John, think you were right, it was a power transistor.

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