Discussion Category:  Centrifuge

Please help resetting voltage on Beckman J-25i

I have a Beckman-Coulter J-25i that I got from a 3rd party. It had been running quite well most of the time, but would shut down on really hot days while giving a "Power" error on the upper right side of the display. We have the centrifuge connected to single phase 208V power, which between you and me, almost always measures out to be 203V under the best of conditions. I thought that a further drop of voltage on hot days would cause problems so, I decided to look where all of the leads were positioned on the transformer taps. The power transformer terminal block on our centrifuge is set up as follows (On the left are the wire colors for wires leading from the transformer to the terminal block): 1. Black / White (2) 2. Grey / Black 3. Red / None 4. Orange / None 5. Yellow / Purple 6. Blue / Grey and Orange (3, one thinner) Can anyone tell me what the proper wiring is for a 208V installation. The grey and orange wires are sitting at about 260V, which CAN'T be right. Thank you, Jim
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jzondlo8505
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dpkleessr

First, where are you located?  IF your in the USA or any other country that uses 60Hz line voltage then follow the following information.  50Hz wiring is a little different.  There is a difference in the transformer wiring if the line in voltage is less than 207 VAC.  207 VAC is the point where the 208VAC wiring is applicable so if the line in below 207 then follow thesee guidelines. 190 to 206 VAC the BLACK lead goes to position 2 on the transformer.  If the line voltage ever gets at or above 207VAC then the BLACK lead goes to position 3 on the transformer.  After proper positioning that lead, try turning on the centrifuge while monitoring the transormer taps for the one that is closest to 230VAC.  That is where you will place BOTH of the ORANGE and PURPLE wires.  This step applies to whatever your line voltage levels are as the compressor wants to be running at a voltage as close to 230VAC as possible and NOT over 230 VAC.  I would leave all of the other wires in whatever positions they are currently at.  Try this out and see how it performs and get back to me.

Don

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jzondlo8505

Thank you Don.    I left the black lead on tap 2 and moved the orange and purple leads to postion 3 (measured at 230V).  After calibrating inertia and windage, my JA rotors and JCF-Z worked perfectly.  Thank you!

However, my JLA 9.1000 and JLA 16.250 would start, reach speed and woudn't run for much more than  minute before ending the run in a rotor error.   (Yes, I did run them loaded, with at least two bottles in them.)  I then checked the distance between the bottom of the spindle hub and the Hall sensor, and this was WAY too close if the specification is 0.04".   I loosened the sensor and pushed it down as far as it would go before retightening it.  After doing this, both the JLA rotors were properly recognized and would run as long as I wanted them to.   I'm conserned that the gap is STILL too small (I measure it at about 0.018").   Since I can't lower the sensor any more, can I raise the spindle hub on the motor shaft?   I notice that there are a number of 2.5 mm hex screws along the hub.   Can these screws be used to adjust the hub height?  After years of repetitively dropping (as gently as possible, of course) heavy rotors onto the spindle, I could see how the hub could be driven down the motor shaft.

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dpkleessr

The other issue to consider is the motor drive mounts.  I have no idea what vintage of the mounts you have because we went thru more versions of them before I retired in 2012 than I can remember.  So, open up the front panel, loosen the bolts holding the swing out chassis in place after releasing the door release cable and then look up at the drive mounts and tell me what color they are and whether there are any color bands on them.  Sagging drive mounts can cause several issues so this is quite important so get back to me when you can.

Don

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jzondlo8505

Hi Don. If I'm looking at the right thing, then the mounts are just metal grey, with no other distinguishing color to them. Have a picture of the mount, but I'm not sure how to attach the image.

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