CD74-5-P +L-C CP2000 Infrared Dryer not functional.

Discussion in 'Heidelberg Printing Presses' started by wunmi-50, Apr 17, 2015.

  1. wunmi-50

    wunmi-50 Senior Member

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    Dear All,
    We have a 5colour CD74 on which we can print but we cannot coat printed jobs due to a fault. The issue is whenever the machine is switched on,the dryer unit should power on the IR Lamps briefly to warm them up but the lamps do not come on.As soon as the machine runs,a dryer error is logged on theCP2000 screen and this picture is attached below.Also the pix of press,dryer nameplates are attached with a sample page of the dryer manual in German,the English version of which i hope someone in this forum can provide for me.

    The water pressures in the dryer cabinet has been confirmed okay but the blowers in the cabinet do not come on hence we suspect it could be due to non initialisation of the dryer control system.To this end we solicit for the technicai assistance of those using similar presses,and others ca can help with suggestions to reolve this problem.
    All inputs will be well appreciated.
    wunmi-50
     

    Attached Files:

  2. Waqas_zahid

    Waqas_zahid Senior Member

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    hello Wunmi-50,

    You should be getting a list of errors for the dryers, where it specifically indicates the problem with the dryers, would you mind sharing a screen shot of that screen?
     
  3. wunmi-50

    wunmi-50 Senior Member

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    Hi Waqas,
    Thanks for this reply, the only valueable error shown is on the lower picture on right hand side where you have the two yellow symbols in the dryer installed area in the delivery. Below these symbols errors 1/1 and 1/3 show dryer fault indicating that the radiator elements in dryer are faulty. However, the elements are okay only power does not get to them because the control contactors are not energised by the plc. This probably mean that some conditions for total dryer initialization are not yet achieved and i am seeking insight to this via this forum.
    Also, i observe that the blowers in the dryer cabinet are not powered on from the plc as soon as dryer panel is switched on though he water pressures are okay.
    I hereby appeal to experienced users and technicians to help shed more light on which other conditions normally has to be carried out during their set up for operation.
    wunmi-50
     
  4. exheidmech

    exheidmech Senior Member

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    So, your issue can have a couple possibilities. Did you check in the cabinet to make sure that there were no fuses tripped? If there are no fuses tripped you need to replace the radiators 1/1 and 3/1. On a machine that age it is not uncommon for those radiators to go out.
     
  5. Waqas_zahid

    Waqas_zahid Senior Member

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    hello wumi-50,

    okay, I need some time to get my head around this problem, it seems the only errors that are being displayed for the two slide in units are defective radiators but as per your observation you do not see any of the contactors for the slide-in units being energized by the PLC, right? So judging by the errors your E1 and E2 cassettes are in error state and your K40 and K50 contactors do not turn on. Whats interesting to note is that the errors are being displayed for particular radiator tubes of E1 and E2 cassettes, whereas if you search through the wiring diagram you will see there is only a single contactor for one complete IR cassette, either E1 or E2. So if the contactor is not turned on then why arent the remaining radiator tubes for the E1 and E2 under an error state?

    The dryer errors can be really tricky to diagnose, I am wondering if you're seeing some other abnormal behavior also, do the dryer icons disappear and appear in quick successions? whats the condition like when you turn on the dryer cabinet main switch and try to run the machine? can you guide me through it step by step?

    Secondly I hope you have checked for tripped fuses as instructed by exheidmech and its best to change the radiators also and reset the operating hours as well.
     
  6. Waqas_zahid

    Waqas_zahid Senior Member

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    Also, just to observe what changes, I would tell you to take out E1 slide in unit complete, turn on the dryer cabinet and observe whats the situation like, do the same for E2 cassette as well, just to isolate the problem isn't coming from any of the cassettes due to a short circuit.
     
  7. wunmi-50

    wunmi-50 Senior Member

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    Dear Exheidmech,
    Lots of thanks for your contributions not only to this post but to numerous others which i have benefited from. Regards this, i can confirm that that there are no tripped fuses and radiators are really not having power to them from the plc.

    Dear Waqas,
    Many thanks for your thorough and insightful contribution thus far,it is highly appreciated. Having gone through your analysis please note the error in my earlier reply on dryer. Radiator fault should actually be 1/1 and 3/1 as corrected by exheidmech. I have taken a deeper look at dryer operations and i submit further observations as follows;
    When dryer power panel is switched on, the system boots up with several processes until contactors k40,k50 briefly power in and then go out. While they were in, either contactor trio k31,k32,k33 OR contactor trio k35,k36,k37 were equally energised but the heaters did not come on because the electronic relays A40 and A50 series were not energised by the plc( for reasons unknown to me) resulting in no heater lamp warm-up and hence errors displayed on cp2000 screen. If i now run press with impression, the contactors A40 and A50 will never re-energise unless the dryer panel is switched off and on again to begin a fresh cycle.
    If you look at the drawings, making a temporary bypass of the A40 and A50 series of relays individually while other conditions above are met resulted in all the heater lamps of the dryers coming on one by one.This way i was able to confirm that the heaters are okay.
    In the meantime, i am going to try out your other suggestions when production is a bit lean.
    Meanwhile, i still need the english version of the dryer operation manual via the cp2000 screen, a german version of sample page is on the RHS, top row of picture i earlier posted. I will be glad if someone in this forum can help me get this.
    wunmi-50
     
  8. Waqas_zahid

    Waqas_zahid Senior Member

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    Hello Wumi-50,

    Thank you for your kind words of appreciation, always a pleasure to be of assistance to anyone in this forum.

    Good to know you took some new observations, they can prove helpful to diagnose the fault and move further on the issue, if your K40 and K50 contactors are working when you turn on the panel then thats a good sign, the system is supposed to do that. When you turn on the dryer cabinet the PLC does an initialization procedure to check the lamps, the respective contactor is first turned on (in our case K40 & K50) and after that the SSR's which are your solid state relays A40, A41.... A50 and so on, are turned on for a short instance, current starts to flow through the lamps and the current feedback reaches the PLC through the CT's (A31 and similar I think in our case) looped around the wires that feed power to the lamps, since we see errors for radiator lamps for E1 and E2 cassettes so we can say the current feedback that reaches the PLC through the CT's for these two specific radiator lamps isn't within the tolerable range. One interesting thing to note is that I think these SSR's (A40, A50) are not simple ON OFF relays, these are proportional control or load regulating relays from crydom, what it basically does is, it regulates it's ON-OFF cycle depending on the input DC voltage it gets from the PLC in order to energize it, I think the range is from 5VDC to 15 VDC, this is what allows the operator to select their lamp power in percentages from the CP2000 touch screen, which leads me to my second point, by bypassing the SSR's A40 and A50 although you have made sure the lamps are OK but we can't be sure if it's drawing the correct amount of current corresponding to the power percentage set or at which the lamps are initialized at, so by bypassing the function the lamps can't be counter checked reliably since the PLC is determining it's health through the Ampere drawn by it, so its possible that although your lamp seems OK but still doesn't draw the correct current and is reported as faulty.

    Anyway to cut it short, you have two possibilities, measure the DC voltage coming from the PLC to energize the SSR's A40 and A50 (I dont know if these SSR's have indication LED's on them) and compare them to the energizing voltage for the rest of the SSR's, if that is OK then you have to replace the radiator 2 of E1 cassette and also radiator 2 for E2 cassette as well. Your other options are to exchange A40 and A50 with any other SSR to check if the fault shifts and lastly make sure all the contacts for K35,K36,K32 and K31 are OK.

    Also I was discussing this issue with a few colleagues of mine, normally when the dryers are turned on the PLC turns on the contactors (K40 and K50) through which the radiators are fed and if an error is detected in any of the connected radiators the PLC shuts-downs the contactor and opts not to turn it on for the remaining operation until the errors are cleared and the system is reinitialized.

    Since it seems the system is entering initialization phase, so I dont think it will be necessary to do the cassette pull out procedure as I mentioned in my previous post. Hope this helps you to solve
     
  9. wunmi-50

    wunmi-50 Senior Member

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    Hi Waqas,
    Thanks for this elaborate insight on this dryer issue. I will do further troubleshooting and give a feedback soonest.
    wunmi-50
     

  10. Waqas_zahid

    Waqas_zahid Senior Member

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    Hello Wunmi-50,

    Most welcome. Please do let us know your findings whenever possible.

    Best of luck!
     
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