Shiner

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Posts posted by Shiner

  1. Posted

    We have a spec sheet for a em 231 analog input rtd 4 input module. It only shows four wire RTD terminations. Is it possible to connect a two wire RTD to this module and if so how is this done properly. 6ES7 231-7PC22-0XA0

  2. Posted

    Thanks again, still learning the siemens side of things and their website is even more segmented than AB. Does anyone else find that these sites are a chore to get the information you are looking for. I am now trying to find data on cabling. I have a 226 processor and a 6" basic touch screen both have the serial port. I have not been able to confirm the wiring pinout or any recommended part numbers. Is there a resource I am missing or a link on their site that will give me that info?

  3. Posted

    yeah I have heard the two platforms are as similar as micrologix is to contrologix....same family different features. One of my biggest concerns is the HMI integration. I have worked with AB Eaton, and Mitsu, but not Siemens. Any pointers or resources, similarities to anything I am familiar with would help. Thanks again.

  4. Posted

    Thanks for all the advice. I have been working with the 200 series cpu for some time without much trouble, but also without much in the way of a challenge. I know the end user has all AB in one building, this is actually in a different building and the customer already sent them their spec sheets calling for Siemens without any negative feedback. I looked at the 1214 cpu with a 6" color. The only unknown here for me is the communication between the two as far as how tagging works on this platform.

  5. Posted

    I have two integrators putting basically the same system into a facility. Our customer is supplying them both with one system each. One customer spec'd AB Panelview 10" touch and an L23E processor. The second customer wants to use siemens. What is the equivelant HMI and PLC that they offer and the same for software. The end user (yes there are four layers of people here, us, the builder, the two integrators, and the end user) has a facility that is all AB ethernet monitored systems. What is the best method for having them talk to each other.

  6. Posted

    The Yaskawas are good for this. On one drive input your 0-10 to V, A1., and AC respectively, program the analog in for 0-10, set reference parameter b1-01 for terminals, set speed ref max and min for analog in and then program the analog out (AM and AC) for 0-10 and then set h4-01 to whatever suits your app

  7. Posted

    There are a few ways to do this. Some work well, some don't. What is your app and drive type. There are drives that can be set as followers in which case you set up drive 1 to read the input (0-10?) and adjust speed accordingly, and then output a signal to the other drive telling it what speed to run. When running two in parallel, you can have voltage fluctuations if the circuit is not designed properly. You should use an external supply, so that the reference is common to both drives and a variance in a power supply from one drive to the other will not cause one to be always faster than the other. Again, it would be easier if I knew the installation and drive type.

  8. Posted

    Is this with or without load. Yaskawa has a stop function on some of their drives that reduces braking time by up to 50% under load over dynamic braking, I can't remember what it is called. I read some of the tech notes on the eurotherm method and it sounds like a similar concept. Realistically, with the way an AC motor works, if you have a large inertial load and plug the motor with enough current it will stop very quickly. It may not do this more than a couple times. The downside is heat, and depending on the manufacturer and type of windings, if the insulation is not bonding the conductors well, short circuit current will cause a conductor to actually move. This is amplified by the number of conducters in the coils, and they all begin to vibrate against each other. Add the heat, the friction of high current situations, and this is a recipie for major failure. You can have drive parameters oversized to do many things to a motor, including shorten its life.

  9. Posted

    That sounds about what I was thinking except for creating seperate routines. The main thing right now is, not having alot of PID experience with contrologix, how to set up the smoothing of the incoming signals. They aare very dirty, even though the cabling is shielded in conduit, I see the count jump quite a bit. My cvoncern is it could jump to a high point and set that as the target, and forever chase a point that was nothing more than a spike.

  10. Posted

    I have read over posts on PID and without practice the deciphering all that information is getting to me. I have a process where I am trying to do two things. First, on initial start up, I want to monitor the output of a device using a sensor. The input of this is very unsteady so I need to do smoothing. I need some advice on how to set this up. The output will increase with temperature until max output is reached. At this point any increase in temperature will begin to decrease the output. I want to record this peak and use it as my setpoint. I would like to do this "on the fly" because the output will also diminish with the age of the equipment (at some point necessitating change which will again change the peak point). So each time the machine is started the max is recorded, and used as my target run temperature with a second sensor for temperature. Second, based on the setpoint, I want to ramp up or down cooling fans to hold the output devices at their optimum temperature that we determined above. The processor is a 1769-L23E-QBFC1. I have 4-20mA going to the drives, 4-20 in from the temp sensor, and 0-10 in from my emitter sensor.

  11. Posted

    Thanks, Yes you are both correct....most of the tags in the HMI are not affected, it is just a processor name change. There is one tag the customer specified that reflects the processor name and is used for alarms and watchdog configs. I was in quite a hurry and have alot on my plate (like most of us) and initially was nervous this would turn into a big project.

  12. Posted

    I am nearly finished with a project that involves two systems, each with an L63E and Panelview 1000. The customer has just come to me and requested a name change to the PLC, acknowledging that the tag names will have to be updated as well. Is there a shortcut to this or do I manually have to go through and reassign all my tags on my HMIs.

  14. Posted

    I suppose it could do some protections, depending on how you are using the drive. If you use one of the aux contacts on the drive and set it up so that the contact closes when the drive is outputting full rpm of the motor, but I don't see it as an advantage. Most of todays drives have multiple types of protection built in, making the need for using the E3 for protection redundant and an added headache to set up. If it were me, I would use the drive for all the protections and the E3 just as a monitoring tool.

  15. Posted

    Thank you that is perfect. I understood that there was an incremental increase, and that it causes accuracy problems, but I did not see what your function was accomplishing. Now it is perfectly clear and thank you for sharing a very simple method of coping with scan time delays.

  16. Posted

    If T4:0.acc is greater than 1000 then increment a seconds counter and subtract 1000 from the .acc. I have read a bit of the posts on this and I know that the end result of a timer running its course and being reset is a value greater than the timebase you set so incremental increases (deviation) in used time occur, but the explanation for why what you have works still is not clear to me. Why subtract that value from the timer. Is the math function faster than the reset function? Isn't there going to be deviation already, you are not performing the math when one second is reached, the expression is when it is greater than 1000 (1 second)

  17. Posted

    In regards to the second drawing two things. The fist example shows a motor feed that is of lower current rating than the main feed. This is a simple protection of the motor from overcurrent (the line will supply way more current than the motor can handle). However, I see in the notes that the disconnect is rated for 30A yet the wire used is 14awg. The standard here (again I know you are in a different country and standards may be different) for 30A is #10AWG. putting 30 amps through a 14 guage wire will make some heat when it is a load such as a motor. The second example shows that the motor is fused at what the line wires are rated for (#14AWG is good for 15A). If something is fused already at one rating, why fuse it again you may ask. This is because the load (motor) is subject to different types of failure. If the motor short circuits, then the fusing for that motor alone will blow, leaving power for the rest of your controls (possibly an alarm light to let you know that there is a problem with your motor. If the fuse ratings are cascaded right, you should only lose one piece of equipment instead of putting a spike on all components.

  18. Posted

    There are many who tend to assume that ground fault is all about total failure when in fact, many motors and transformers are in some state of ground fault. I cannot count how many times in my career as a motor repair tech that a customer brought us a running motor for preventative maintenance and it failed insulation tests due to dirt, grease, moisture or some contaminent. These motors would not be 'blown', just near failure and with a good wash and bakeout they would run for many years to come. It used to be you had a plant electrician who would megger test all the critical motors in a process and log the results. A difference in readings over time indicated the need for attention. Now in today's economy, the maintenance personnel either does not have the knowledge, tools, or more often ability to take the piece of equipment offline to perform the test. That is if there is a maintenance department at all. Having a control system designed to monitor these conditions automatically is becoming more commonplace as companies try to find ways to keep running with minimal overhead.

  19. Posted

    Depending on the size of the motor and the application, detecting ground fault early can save much in maintenance costs. I am not sure what you have, but say you have a large costly motor. The mechanic on night shift has nothing to do so he overlubricates the bearings. The grease leaks out all over the windings till they are saturated. Eventually depending on the type of grease and type of wire used in the coils, the insulation can break down or leak some current to ground. If the sensor trips out first by detecting the low levels of fault, now you can simply send the motor to a repair shop to be cleaned and possibly redipped (another coat of insulation applied). This is much more cost effective than letting the fault grow till a short occurs, making a full rewind or replacement necessary. There is a manual available for these http://samplecode.rockwellautomation.com/idc/groups/literature/documents/um/193-um002_-en-p.pdf and if you read it you can see that there are many available monitoring features that help protect the motor such as phase loss, current imbalance and things like that. Some can be simply for monitoring purposes only, but being a solid state device it should protect faster than old fashioned overloads (heaters) that are based on heat and time. Remember that the heat that trips those is also being applied to the windings of your motor.

  20. Posted

    There is no spec yet for a required processor type, nor has a budget been defined. The customer is looking at this project with year end increase in productivity in mind, and if we get close to the 10% increase we are shooting for, budget probably will not be too big a concern if it is reasonable. The material is a hardened concrete type product, with uneven and porous surfaces.

  22. Posted

    how hot is hot? Do you have an IR temp reader? What kind of time period are you powering down for? AB has a list of what may corrupt the memory on these series processors. http://au.rockwellautomation.com/applications/gs/ap/gsau.nsf/pages/SLC500_Installation_CheckList

  23. Posted

    You have a 50/60 hz 4 pole motor. At 60Hz it is only useable at 460v, probably due to the amount of backiron, but at 50Hz you can connect it Delta for 220-240v or Wye (star) at 380-420v. It is 3 phase, seen at the top, and the RPM factoring in slip, at 50Hz is 1455 rpm and at 60Hz is 1755 rpm. If you know how manyu leads, there are references on how to connect for Wye or Delta. Usually a six lead motor is W1 U1 and V1 to L1 L2 and L3 respectively, and tie together W2 U2 and V2 for Wye, Or if labeled 1-6, 1 2 3 to line 4-5-6 together. Let me know if you need more info, Part of our business is motor repair so we have extensive reference material.

  25. Posted

    Instead of rewriting the logic for each set of variables,write it once and you can store the different variables and load them into the presets for the counters and timers. for example, if button X on the hmi is pressed to enable recipe A, load variables N into T1 PRE, M into C1 PRE, and one down the line using MOV commands. This will minimize your program.