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avatar: demircha999
demircha999
2 posts
Replied to demircha999's post on February 22nd, 2011

We have Beckman optima XL-80 ultracentrifuge and vacuum is not going below 40 micron. We replaced the diffusion pump oil but it still stuck at 40 micron.
What are the other possible reasons for low vacuum? Is there a solution other than changing diffusion pump oil and vacuum pump oil?
Thanks.

avatar: LabWrenchManager
LabWrenchManager
610 posts
Replied to demircha999's post on February 23rd, 2011
I would first check all the tubing off the vacuum for leaks and check that the o-ring for the door is not cracked. I would also leave the vacuum pump on overnight for purge of moisture contamination.

Thanks to Alexandre Jesus for providing this response to LabWrench
avatar: Larial
Larial
4 posts
Replied to demircha999's post on April 4th, 2012

What is the correct amount of diffusion pump oil to use in the Beckman L8 series of ultracentrifuges?

avatar: rseberlin
rseberlin
1 posts
Replied to demircha999's post on April 4th, 2012

Absolutely check for leaks.

Is there vacuum grease on the seal? Is the seal in good condition? Are the vacuum hoses in good condition and on properly? Is there enough Vacuum pump oil in the vacuum pump. is your vacuum pump in good condition. Typically your problem will be somewere in this area.

avatar: TheLabSquad
TheLabSquad
14 posts
Replied to Larial's post on April 4th, 2012

Drive oil:  360 ml. (must use Mobil 1 (5W – 30) oil, Beckman P/N341660. Bottle contains ~360 ml.)

avatar: TheLabSquad
TheLabSquad
14 posts
Replied to TheLabSquad's post on April 4th, 2012

Correction,  for Diffusion Pump ...100ml of Beckman PN 330246

avatar: Hurd Electronics
Hurd Electronics
14 posts
Replied to demircha999's post on April 4th, 2012

Mobile 1?  I never heard that one before.  The vacuum pump needs the best quality silicone high vacuum pump oil you can get.  If there is any color to it, change it.  It can absorb water and lose efficiency.  Also, try running the vacuum pump overnight with the gas ballast open halfway, then close it up and your vacuum should increase.  I have a diffusion pump in stock if you need to replace it.

avatar: TheLabSquad
TheLabSquad
14 posts
Replied to Hurd Electronics post on April 4th, 2012

Well,  as I posted in my 2nd response, the diffuser oil is actually a different PN.

However, just to clarify... I'm pretty sure Beckman Coulter  does not refine their own oil products.

If you check out the MSDS spec for 330246 on Beckman's site you can compare that with a variety of equivilent oils available from Granger or other industrial supply houses.  Even lesser known company's like Mobil make pump oil   :)

avatar: Hurd Electronics
Hurd Electronics
14 posts
Replied to TheLabSquad's post on April 4th, 2012

Ahh, yes Mobile 1 makes vacuum pump oil, but don't use their motor oil in your pump by mistake!!  

 

Diffusion pump oil is very different from the vacuum pump oil and is very expensive as well.

avatar: TheLabSquad
TheLabSquad
14 posts
Replied to Hurd Electronics post on April 4th, 2012

Okay, so I guess we agree you need to replace your diffusion pump oil with either Beckman #330246 or an equivilent. 

To determine if correct amount of oil with spindle removed, measure distance from top of drive housing to oil; should be 7 1/2 + 1/8".

Assuming you have done that, you need to verify that there are no leaks as noted above.

To check pump operation, try either of the following;

1. Monitor vacuum at pump inlet.  Should pull <20 microns.  Turn off pump and vacuum should stay <50 for at least 20 seconds.

2. Make instrument pull chamber vacuum to below 10 microns.  Unplug pump and vacuum should stay <50 microns for at least 20 seconds.

If pump fails either test, rebuild with maintenance kit there were several pump models) or replace.

 

avatar: howard2012
howard2012
17 posts
Replied to Hurd Electronics post on April 4th, 2012

I'm not a Beckman expert, but am involved with vacuum pumps every day. I would suggest that the diffusion pump oil is equivalent to Dow Corning silicone 704. 705 is probably not required and it is more costly than 704. Silicone oil resists oxidation better than the original hydrocarbon oils that were used in diffusion pumps. Mobil 1 oil may be OK for a single stage rotary vane vacuum pump but high vacuum pump oil such as Inland 19 should be used in any two stage rotary vane vacuum pump. If the mechanical pump is an Edwards RV then Ultragrade 19 should be used as the RV pump is designed to run hotter than other similar models.

avatar: howard2012
howard2012
17 posts
Replied to Hurd Electronics post on April 4th, 2012

I'm not a Beckman expert, but am involved with vacuum pumps every day. I would suggest that the diffusion pump oil is equivalent to Dow Corning silicone 704. 705 is probably not required and it is more costly than 704. Silicone oil resists oxidation better than the original hydrocarbon oils that were used in diffusion pumps. Mobil 1 oil may be OK for a single stage rotary vane vacuum pump but high vacuum pump oil such as Inland 19 should be used in any two stage rotary vane vacuum pump. If the mechanical pump is an Edwards RV then Ultragrade 19 should be used as the RV pump is designed to run hotter than other similar models.

avatar: Larial
Larial
4 posts
Replied to TheLabSquad's post on April 10th, 2012

Are you sure about the 100 ml volume.  That sounds like it might be sufficient for the small diffusion pumps on the tabletop TLA and TLX ultracentrifuges but is probably insufficient for the larger diffusion pumps in the L8 series preparative ultracentrifuges.  I would think at least 250 ml would be required for these pumps.  Did you obtain the 100 ml estimate from a service manual?

avatar: TheLabSquad
TheLabSquad
14 posts
Replied to Larial's post on April 11th, 2012

Yes.   If the level is low, you will get a DP error message (pump oil low, running hot).

Take note of how much you remove.

avatar: Larial
Larial
4 posts
Replied to TheLabSquad's post on April 11th, 2012

I don't think you are following me properly on this.  We're talking about older model L8 series of Beckman ultracentrifuges (eg L8-70).  The diffusion pump is in line with the rough-in pump.  The amount of diffusion pump oil in these units is at least 250 ml or greater.  Where did you come up with 100 ml?

avatar: Craig1
Craig1
72 posts
Replied to Larial's post on April 27th, 2012

The L8/L8M//L7/Optima diffusion pump uses 100ml silicone oil (Dow Corning silicone 704 or 705).

TL/TLX diffusion pump is 55ml.

I work on these every day.

avatar: wang
wang
1 posts
Replied to Craig1's post on April 27th, 2012

I have an old Beckman L8-M ultracentrifuge and I would like to know if you have an instruction manual of changing the diffusion pump oil. Thanks!

avatar: Craig1
Craig1
72 posts
Replied to wang's post on April 27th, 2012

Quote wang

I have an old Beckman L8-M ultracentrifuge and I would like to know if you have an instruction manual of changing the diffusion pump oil. Thanks!

Turn instrument off and unplug from wall!

Remove front cover, remove the vacuum hose from the diffusion pump.

Remove the oil drain plug (copper), drain oil into a beaker. 

Replaced drain plug ( it should have a copper washer between the nut and diffusion pump)

Either add silicone oil or replace all of it to 100ml level.

Slowly pour oil into the diffusion pump (where the vacuum hose was)

Replaced hose, front cover, plug in and test.

avatar: KenP
KenP
2 posts
Replied to Craig1's post on August 27th, 2012

Hi Craig,

I have an old L8-70M and I left it on for a few hours when not in use and the temperature increased to almost 40C, I then turned it off and it took hours to cool down.

When I tried to run it again after pre-cooling to 5C, it would only spin to 3000 rpm and the vacuum would not go down to the point where numbers were showing.  Also after putting the rotor in, the temperature wouldn't decrease back down to 5C also.  After starting the run, since the speed would not exceed 3000 rpm, I stopped the run and let the vacuum run for longer and it the vacuum would not decrease to the point of showing values.  Then I tried to start it again and the error TACH came on.  I turned it off, waited, and tried again, and the error DSK2 came on.

Can you shed any light on these problems and the extent of repairs required.

Thanks!

avatar: Craig1
Craig1
72 posts
Replied to KenP's post on September 4th, 2012

Ken,

The 1st problem sounds like a leaking solid state relay on board #9.  It is causing the heater band to always be ON. 

The other problems may also be the #9 board. There is a oil pump in the drive, is sounds like the pump is always ON and the drive oil is being pushed out of the spindle. This will cause the tach and overspeed sensors to get oil in them. You can clean the bottom of the spindle the methonal/alcohol and check the overspeed disk on your rotor, replace if it is scratched or dented. Have you added drive oil? Maybe you added too much. 

avatar: doodle50
doodle50
48 posts
Replied to Craig1's post on October 18th, 2012

I find that a 60ml syringe with a bit of tubing allows you to measure what you put in and is a convienient way to actually put it in.

avatar: Ric
Ric
36 posts
Replied to demircha999's post on October 19th, 2012

Is the diffusion pump actually getting hot?  Caution!  It's too hot to touch!

Ric

avatar: KenP
KenP
2 posts
Replied to Craig1's post on October 21st, 2012

Hi Craig!

Thanks a lot for the reply and my apologies for the delay.  I meant to reply but it appears I forgot.

So I noticed the chamber was full of grease as well as the bottom of the rotor.  I wiped everything down including the bottom of the rotor and the ultracentrifuge had no problem with operations.  I did contact someone online about the problem and he said that the oil could have to do with the spindle about to break and this could cause catastrophic failure and loss of life.  Even though I'm pretty sure it was oil from overheating, I decided not to use the instrument.  Since then, we've been waiting for the service contract to get through administration and there has been no movement on that front.

To answer your question I absolutely did not add any oil since I'm no handyperson.

I'm not particularly worried about the spindle failure but would rather play it safe than sorry.  The only thing that worries me is that with so much oil everywhere, I'm guessing one of the components somewhere inside is missing oil.

Any thoughts on the missing oil and spindle breakage?

When the service person eventually comes, I'll mention the board because it gets really hot. 

Thanks again!

avatar: gonzalezvaa
gonzalezvaa
3 posts
Replied to KenP's post on December 10th, 2012

Hi Craig,

I have a L8-70M centrifuge and this has problems with the vacuum and  temparature displays. Both are always blinking around three values. I´ve ckecked the amplifier and the voltage frecuency convertert on the board 1 and board 3, but all it´s ok. 

Have you seen this fail before?

I have another question, Have you worked with L5 Beckman´s centrifuges?

 

 

avatar: paul220
paul220
5 posts
Replied to Craig1's post on February 27th, 2013

Hi Craig-sorry to hijack the thread but i have an issue with a tlx optima benchtop ultra centrifuge whereby when in operation the temperature keeps creeping up until it triggers an automatic shut down-we are waiting for an engineer but are worried as this machine is now 21.....also we noticed that once the stop button is pressed during a run the temperature will quickly fall back down to its set point... do you think this is going to be repairable?? 

avatar: howard2012
howard2012
17 posts
Replied to Hurd Electronics post on February 27th, 2013

Guys, make a clear difference between the diffusion pump and the mechanical pump. Referring to vacuum pump doesn't tell you which it is. The mechanical pump will use hydrocarbon high vacuum pump oil either from Beckman (expensive) the pump maker (also expensive) or a supplier such as Inland Vacuum or Kurt Lesker. The diffusion pump uses silcon oil, equivalent to Dow Corning 704 probably, check the manual. When troubleshooting vacuum systems always start at the mechanical pump. 40 microns is a mech pump vacuum reading. Put a vacuum gauge head Pirani or ThermoCouple on the inlet and see what it reads. It should read below 40 microns, down towards 1 micron would be good. If the mechanial pump is good, check the piping or include the diff pump up to the high vac valve and see what the reading is. Eventually you can include the centrifuge body volume. Be catious if leaving a mech pump on gas ballast overnight. It is possible to exhaust all the oil as mist out of the exhaust into the mist filter. If the mech pump runs out of oil you will have an overheating problem possibly a pump seize up. Happy troubleshooting! I know the vac pumps, not so much about the instruments. Regards, Howard

 

 

 

 

avatar: Craig1
Craig1
72 posts
Replied to gonzalezvaa's post on March 1st, 2013

Sorry for the delay in getting back to you. I have not seen the problem you are having with your  L8M. I would suspect the backplane board (connected to the keyboard pane).

I haven't worked on an L5 for many years. What do you need to know?

avatar: Craig1
Craig1
72 posts
Replied to KenP's post on March 1st, 2013

Hi Ken,

Hope you got this fixed. I've never heard the spindle is about to break comment before. Maybe what he was trying to say is that if the oil is low (from leaking to chamber) the spindle bearings may sieze up and fail. 

Craig

avatar: Craig1
Craig1
72 posts
Replied to paul220's post on March 1st, 2013

Quote paul220

Hi Craig-sorry to hijack the thread but i have an issue with a tlx optima benchtop ultra centrifuge whereby when in operation the temperature keeps creeping up until it triggers an automatic shut down-we are waiting for an engineer but are worried as this machine is now 21.....also we noticed that once the stop button is pressed during a run the temperature will quickly fall back down to its set point... do you think this is going to be repairable?? 

I would look at the drive mounts and bellows seal. Good luck.

Craig

avatar: gonzalezvaa
gonzalezvaa
3 posts
Replied to Craig1's post on March 13th, 2013

Don´t worry about your delay Mr. Craig.

Well, the L8M centrifugue has problems with vaccum and temperature indication. Both readings are blinking around three values (high value, real value and low value). I don´t know if I´m not wrong but I think those readings should be estable even If I try on to calibrate any of this parameters (temperature or vaccum) . I´ve made some measures on boards # 1 and #11 and I´ve not seen any problem on both boards. 

My question is if you´ve seen this kind of failure before.

The other centrifuge (L5) run perfectly but has problem with temperature controls. I don´t have schematics or service manual for this equipment. Do you have any information, I mean, diagrams o service manual about this?

Thanks