drforsythe

MrPLC Member
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Everything posted by drforsythe

  1. controls for small application

    There is no image. Also: is there an existing control system that these sensors, fan and alarm will be connecting to?
  2. One-Shot

    Balluff has an inline signal conditioner that is designed to be used with switches like proximity and optical switches. It can be taught to act as an ON delay or an OFF delay with an adjustable time. This product would probably work in your application. Other manufacturers of industrial switches have similar devices. The Balluff unit is known as a "Signal Adapter BOS S-T". Info for this device can be found on their website. If you happen to have a Balluff catalog, it will be in the 'Accessories' section. Does your cutoff machine have a controller in it? If so, you could modify the program to only act on the positive transition of the switch. I am sure you have already thought of that and are looking for an alternative, though. Hopefully this is helpful.
  3. Fantastic info. Thanks for sharing.
  4. Enclosure Assembly

    If loading using straps or chains and a hoist (which you probably are), a spanner is definitely the safe way to do it. Nylon straps work better than chains. Once the Hoffman hooks are in place, they typically do not move if the even tension is applied to each hook. Another option could be magnets if there is room on the subplate after assembly. It is common to move large steel plates using this method. The lack of open panel space after assembly would probably not allow this, though.
  5. Enclosure Assembly

    Hoffman Enclosures has panel lifting hooks available. The catalog number is APLH. The catalog does not state the maximum load, but we use these to place large and medium size panels into the enclosure and onto the studs. Check out www.hoffmanonline.com for more info.
  6. Vertical Servo Axis (using G5 servo)

    We have systems in-house that utilize a "brake override" to allow maintenance of the axis. It utilizes a normally open relay contact (as described above) in parallel with the contacts for the safety and monitoring circuit. The coil leads are run to a connection point where an external power source is connected. The external power source has a momentary pushbutton in it to allow power to flow to the coil of the oveerride relay when pressed. The connection point utilizes a connector to make connections easy. We store the brake override power supply in a separate location from the machine where only our Maintenance or Engineering departments can access it. BE CAREFUL DOING THIS ON A VERTICAL AXIS, THOUGH! Doing this on a vertical axis requires a good procedure and proper devices to control the descent of the axis when the brake is released. You may want to think about how you would do that on your machine (blocks, slings, crane, come-along, etc).
  7. Vertical Servo Axis (using G5 servo)

    A standard way to do this is to use a brake that must be energized to release. You would then create a series circuit for the power for that brake. The series circuit would include your safety circuit (MCR or safety relay), the fault output for that axis and an output from the servo drive that is active when the servo is enabled. You may need to use relays on the fault output and enabled output, if they are not already contact outputs on the servo drive. This way, if the safety circuit is not enabled or there is a fault on the drive or if the servo is not enabled, the brake will clamp the motor shaft and not allow it to move. Depending on the application, you may need to use a safety relay with a time-delayed output for control of the brake.
  8. Mitsubish Training General info

    If I were in your position, I would start by taking an inventory of the controls equipment that I would be responsible for. I would record model numbers on all PLC CPUs, I/O cards, analog, motion, network or other cards in the rack. I would also look into the types of human machine interface products. If you have drives, record them also. Then I would check to see how all of the stuff on the equipment "talks" to each other (digital I/O, ethernet, MelsecNET, CCLink, serial, etc). Once you have an idea of all of this, I would ask your local Mitsu rep for a list of classes that might assist you on your journey. Depending on your troubleshooting and other electrical skills, you may also want to look into some general classes. The bottom line (as you probably learned long ago) is that the classes will give you the foundation or starting point. Old fashioned, hands-on training will get you the farthest. I hope this response was not too general for you. Take care and best of luck!
  9. PLC Mitsubishi Help

    I agree with kaare_t. We need more information. As an alternative, have you tried getting your local Mitsubishi office or distributor involved? If they are too far from your location, there may be a local integrator that they can refer you to.
  10. PLC Mitsubishi Help

    If you have replaced the drive and card, did the correct parameters get loaded? A little more info on the hardware might be helpful as well. You might also want to say where you are located, as one of the talented people on this site might be able to pitch in some on-site help if properly per$uaded.
  11. Regenerative fault.

    Does this fault occur only when you stop the motor, or when it is commanded to run? Does it ever happen when the motor is sitting still? Can you connect a meter or recorder to the output of the drive? You could monitor the actual voltage on the motor leads when the motor is stopped. If the drive is in a stop condition but voltage is present, then it is indeed regen. An alternative thought is that you may have a high input voltage condition. The high input voltage will cause a higher DC bus on the drive. When the DC bus gets high (either due to regen or a high input voltage), you will get an F05. If your incoming power is high, you can suggest gathering more info on the power supply. If it is always on the high side, you may need to change the tap on your plant's power transformer. If the trips occur only at certain times of the day or night, then it could be the power company switching their power factor correction capacitors. If it is a slightly high power or from a fluctuating incoming power, a line reactor could be added to the input power side of the drive (if not already equipped). Sorry for the brain-vomit- I just typed issues that I have seen in the past with variable freq. drives.
  12. MCGS Operator Interface Panel Software

    RussB: We understand the risks of buying such equipment. We have a problem to solve in order to make a more manufacturable and easier to use product that this machine can help with. The machine was purchased to be used as a research and development project. We knew full-well that the machine was inferior to anything we could design and build ourselves. However, the machine was a standard piece of equipment, readily available and already doing some of the features we need at our Chinese manufacturing facility. We will be taking the lessons learned about our process needs and the existing machine to create one that will fully meet our needs. If anyone is interested in hearing about the shortcomings of this machine, I can show you the list we generated prior to ordering it when we justified the cost. Guess what? The cost was still justifiable even with the changes. Will the machine run 20+ years with no issues? No way, but it will run long enough to suit our needs. That being said, hopefully I can get a response from someone who can source me the software so I can correct the spelling mistakes and streamline the screens.
  13. Regenerative Overvoltage Trip During Constant Speed

    Check for a good ground for the vfd supply and make sure the motor is grounded at the vfd ground connection. I have seen this before. I have even seen a drive show this fault when the motor was not commanded to move and the motor de-energized. The drives are set up to protect both the motor and vfd. Sometimes this sensitivity can lead to nuisance faults. I don't guarantee this is the problem, but I have seen this problem disappear after ensuring good grounding practices were used. Good luck, Derek
  14. RSL5K I/O assignment

    Are the inputs and outputs that you wish to use already in your system (spares)? If so, are they on the main rack or on a network node (like Flex I/O?) If they are on the main rack, then locate the rack location and I/O point in that slot. (All slots are numbered starting at 0 (from the left). If it is an input, the address will be Local:x:i.data.y, where x is the slot number and y is the input point. For outputs, the numbering is the same, but replace the I with an O.
  15. 87hz drift with FR-E700

    Please attach full nameplate data of both the motor and the inverter. A close picture of both would work.
  16. ABB ACS 800

    What type of acceleration setting do you have? Also, what mode are you running the drive in? If it is set for DTC (direct torque control), then you will need to let the drive do and ID Run. This sets up the DTC settings. If not set properly, the motor will not perform properly. See the manual.
  17. Logix5000 V20 won't start

    I had this happen on my desktop pc which runs XP. My IT dept was ushing updates and one morning RSL5K would not start with the same symptoms you described. I went back to a previous restore point and all was well. I have since blocked automatic updates.
  18. Allen Bradley Vendor Pricing

    This happens to us occasionally when our annual negotiated pricing expires. You get what you give out of your vendors. If you simply place orders when you need something without reaching out to your vendors, you may get pricing that is close to list price. Our AB distributor is fantastic. They help when needed and stay away when I don't have time. I keep them posted on my projects and they keep me up to date on new products and technical issues. I recommend checking out your available distributors and finding which one can give you the best LONG TERM bang for your buck. You may find that once they get to know you and the potential your company has to their bottom line, that you can get good discounts AND good service.
  19. The encoder must be set by the manufacturer or authorized repair center in order to properly commutate the motor. as MichaelG stated, you might get lucky, but that is not usually the case with replacement of the motor's encoder.
  20. Ideal AB Module for pulse control of a dosing pump

    Does this pump require a single pulse to make it work, or will you create a series of pulses in order to get the right amount of chlorine? If you have to turn on the output multiple times per second or with high frequency, an electronic output would be preferred. Can you give more details on what is required for the injection pump?
  21. RJ45 and power cable in an inverter panel

    I run the cables separate as a best practice when possible. It is not a good idea from a theoretical standpoint to run the high power cables in the same run as the signaling and low voltage signals. However, I am not aware of a standard that requires it. If I am wrong, maybe someone will present us with the specific code.
  22. RJ45 and power cable in an inverter panel

    When I use a drive with ethernet, I just try to separate the cables as much as I can in the control enclosure. There isn't much you can do when it comes to the point of entry on the drive, though. You should be able to get at least 2-3 inches of separation there as well. That should be adequate to reduce or eliminate induced noise on the ethernet cable. The best recommendation I can make is to use shielded ethernet cable, not a "typical" office ethernet cable if you have noise issues. Simple routing of cables should be good enough, though.
  23. Pluto Jokab Safety PLC

    I agree with RussB. If you do not need the programmable aspects of Pluto, I would go with a Vital. We use them and try to reserve safety PLCs for only the large systems where a hardware solution would be too cumbersome.
  24. Rockwell Automation Fair

    Automation Fair will be November 7 & 8, 2012 in Philadelphia, PA.
  25. The Meaning of this article

    Inductive loads cause a current inrush that will result in much higher than rated current when first turned "on". Likewise, when the magnetic field collapses when turned "off" there can also be a spike in current. If you turn on and off an inductive load rapidly, the resulting current may exceed the rated current of the output. This can cause premature failure of the output . Some output modules have a current limiting circuit which could cause it to trip. Hopefully this explanation makes sense.