Avanti J-26 XP showing FRS when using the JLA 8.1 rotor

My company has an Avanti J-26XP with FRS problems. In my case it proved very difficult to find. First, let me share with you these codes provided by a retired Beckman tech that could come in handy for you: "OK, here's how you bring an Avanti J and NOT an Avanti JI series back to life as the codes to clear the diagnostic errors out is different for the two series of centrifuges. You must enter all of the codes in rapid succession because if you pause longer than 2 seconds, the centrifuge goes back to its waiting state. Also, ALL codes begin with the same sequence: [SET/ACTUAL], [ACCEL], [SET/ACTUAL], [DECEL] so get used to entering this sequence followed by the other two entries to get to where you need to be or something that you need to do. So, lets begin by checking the diagnostic messages in memory. Press: [SET/ACTUAL[, [ACCEL], [SET/ACTUAL], [DECEL], [TIME/HOLD] TWICE and then you can view all of the diagnostic codes in memory. Press [CLEAR] to remove eac h of the codes as they are displayed. Next, you need to clear the S7 SYSTEM diagnostic. Press: [SET/ACTUAL], [ACCEL], [SET/ACTUAL[, [DECEL], [TIME/HOLD], [ACCEL]. Press [CLEAR] to clear the diagnostic. To clear the Door Lock Timer: [SET/ACTUAL], [ACCEL], [SET/ACTUAL], [DECEL], [TIME/HOLD], [DECEL]. You should hear the door unlatch at this point. Press [CLEAR] to clear the diagnostic. To clear a System Lock-Up, which doesn't happen very often: Press [SET/ACTUAL], [ACCEL], [SET/ACTUAL], [DECEL], [RPM/RCF], [TIME/HOLD]. 1.) Elevation in METERS: [SET/ACTUAL], [ACCEL], [SET/ACTUAL], [DECEL], [ACCEL], [DECEL] 2.) Ambient Air Pressure: [SET/ACTUAL], [ACCEL], [SET/ACTUAL], [DECEL], [DECEL], [RPM/RCF]. Turn the SPEED knob until it matches the TIME display. 3.) The next item you really need a vacuum gauge hooked up to the yellow tygon tubing that goes to the vacuum sensor on the power distribution board, which is located on the lower left hand side of the centrifuge. You also technically need to compensate for the altitude where you are located and I cannot locate my compensation chart for that. What this procedure does is compensate the for the fact that the rotors will be running under vacuum, at altitude, when the windage and inertia checks are made and when the centrifuge is actually running. Again, hopefully this value will be on the decal on the front of the centrifuge behind the front panel listed as the P4 value. If it's not there then we will have to try something different in order to get the correct value. 4.) To have the centrifuge calculate its own values for windage and inertia, which I recommend, because it takes into account for the current state of the centrifuge, enter the following: [SET/ACTUAL], [ACCEL], [SET/ACTUAL], [DECEL], [RPM/RCF], [DECEL]. The centrifuge will perform an INERTIA calibration first. The set speed will change to 4,500 RPM, and the set time to 1 hour to do the inertia calibration. It NEVER takes and hour to do the calibration! Press [START] to begin the calibration process. After it finishes with the inertia calibration, the system will change to the WINDAGE checking speed plus 500 RPM for the rotor that you entered and you MUST enter the rotor that you are using BEFORE you start this procedure. You need to let the centrifuge complete all three steps to this process. There will be times that the centrifuge APPEARS to be done but wait before pressing the STOP button as it does pause somewhat between steps and some of the steps will be repeated in order to get solid values for each of the parameters. This should take no longer than 30 minutes so just be patient. After it completes this step you will be back to normal operation PROVIDED that you do not have any electronic or mechanical issues that need to be resolved. If you want to just enter the values manually, based upon the values on the decal, then you will need to do the following three steps. Enter/ Check the 900 to 1900 RPM value: Press [SET/ACTUAL], [ACCEL], [SET/ACTUAL], [DECEL], [ACCEL], [RPM/RCF] and then rotate the SPEED knob to indicate the value on the decal for this setting. Press [SET/ACTUAL] to store the value. Enter/Check the 3,000 to 3,500 RPM enertia value: Press [SET/ACTUAL], [ACCEL], SET/ACTUAL], [DECEL], [ACCEL], [TIME/HOLD] and enter the value on the decal for this setting BY TURNING THE SPEED KNOB to the correct setting. Again, press {SET/ACTUAL] to store the value. Enter/Check the Windage Calibration: Press: [SET/ACTUAL], [ACCEL], [SET/ACTUAL], [DECEL], then press [ACCEL] TWICE. Enter the value from the decal by once again turning the SPEED knob to the correct value and then press [SET/ACTUAL] to store the value. You should now have a functional centrifuge. Sorry for the delay in getting back to you all but I am in the process or relocating and free time is in short supply right now. Good luck and let me know how it goes. If anyone needs the Avanti JI series codes then please post a message and I'll take care of those too. Don" The P4 Test is what you will need to determine if your centrifuge has a leak or not. [SET/ACTUAL], [ACCEL], [SET/ACTUAL], [DECEL],[DECEL], [TIME/HOLD]. The centrifuge should then start the vacuum. It should be able to achieve 163 torr within 130 sec. The vacuum should then shut off. If it doesn't, it is likely you have a leak somewhere. You said that you a reading -9 psi? The unit operates in Torr pressure units. I'm not sure if this conversion is right, but -9 psi = ~465 Torr. Which is not nearly low enough for the FRS to operate properly. I was never able to find the leak on our J-26XP. I tried replacing the tach boot, the motor mounts, the vacuum lines, the pressure sensor, refurbing the pump, cleaning the gasket, etc. Nothing worked. Eventually, I just tricked the centrifuge into thinking it was at the correct vacuum by connecting a resistor of the right value across pressure sensor outputs. I then adjusted the elevation and ambient pressure settings. The unit basically thinks it is several thousand feet above sea level so now the ambient pressure is much lower and the vacuum doesn't have to work as hard to reach the 163 torr. Of course this reading is not correct. But the vacuum is only required to help reduce drag on the rotor and prevent the refrigeration system from working too hard. At this point our J-26XP is well over 10 years old. This repair was done just to get some more life out of it. Probably not a recommended solution if you work in a GMP or highly regulated environment. But this repair did prevent the FRS errors. I did it over a year ago and the centrifuge still runs fine. Good luck! -Frank

Hi Frank, Thank you for all the helpful info! It's a big resource. I haven't located the leak yet, but I'm waiting on approval to order a new gasket and motor mounts in case they're involved. Once I replace those and the problem persists, I'll follow your instructions and possibly try the altitude trick (clever idea!). It'll take some time, but I'll definitely update you on any progress. Thanks again for your support! Best Paulo.

Hi Paulo, glad to help! So just a bit of a warning. I also tried replacing the gasket. It is ~$800. But the one Beckman sent us was slightly too small. Even though they claimed it was the part we needed. Also, the gasket is very difficult to replace. I would make sure you exhaust all efforts before replacing that gasket. I would even suggest grabbing the motor mounts and replacing those first. Let me ask you this - do you only use the 8.1 rotor? If not, does the FRS error occur with other rotor types you use? It could be a good experiment to try. Because the 8.1 rotor is the largest size rotor. It might be putting more load on the rotor motor causing it to sink which is affecting the seal of the boot. That would be a good indication that the motor mounts need to be replaced. If that is the case, you also might want to replace the tach boot because that might have gotten warped over time due to the bad motor mounts. So I would start with replacing the mounts and the boot first before replacing the gasket.

If all that doesn't work, I can give you some more details on the 'resistor across the pressure sensor' trick I did. Basically, a pressure sensor is a variable resistor - a resistor whos resistance is affected mechanically by changes in pressure. So by placing a resistor across it's output, you are changing it's overall resistance. Which in turn, will change what the centrifuge reads as the chamber pressure. This trick worked really well for keeping our centrifuge running. Be advised, the centrifuge is now operating at a vacuum that is not as strong as it should be. So the refrigeration system will have to work harder. And you should recalibrate the motor (using the codes I gave above) because that change in vacuum will affect the forces felt on it. But still, this trick works great for getting more life out of this centrifuge. Because it is possible that the reason for your leak is that the whole chamber has sank into the foam chassis which is causing the seal between lid and gasket to be poor. And if that is the case, there's nothing you can do to fix it. So the resistor trick is good for getting around some of these problems.

Hi Frank, Yes, it seems to be occurring only when using the 8.1 rotor. I'll double-check this with additional tests, but for now, the evidence points towards a motor mount issue. I've included a gasket in the order just to be safe, let's see if the one we receive will be a similar size or smaller as well. Anyway, it will take some time to receive the parts as we are still waiting for approval and our department is under some structure changes. Thanks again for the additional suggestions! If replacing the mounts and tach boot doesn't resolve the issue, we'll move on to plan B: replacing the gasket. If none of that works, I will use the last resort, the resistor trick :D Best!

Definitely sounds like the motor mounts to me. They are fairly easy to replace. Good luck. I'm curious to see how you make out!