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  • Rational Service34 -24-

     stuartreiman updated 2 months, 1 week ago 5 Members · 11 Posts
  • holmanelectrical

    April 30, 2020 at 2:32 am

    How do you read this Rational SCC201 fault ‘Service34 -24-‘ (see pic)?

  • techtownmayor

    April 30, 2020 at 3:23 am

    If it is any help, we have a full list of SCC service codes here:

    Rational SCC Service Codes

    • holmanelectrical

      May 19, 2020 at 2:26 am

      Found 2 new ones for you. (SCCWE101)

      Service 52 – Control of Cabinet Light Faulty

      Service 53 – unknown???

  • holmanelectrical

    April 30, 2020 at 4:03 am

    You are a legend!! (you made me re-read it!!) I never read the bit about combined faults…

    <h3>Service 34.xx</h3>

      • 34.1: Motor top
      • 34.2: Motor bottom
      • 34.4: Ignition module top
      • 34.8: Ignition module bottom

    eg Service 34 -24- is actually 2+4, or

    • 34.2: Motor bottom
    • 34.4: Ignition module top
    • or the Older Rational Training Manual 2002
    • 34.2: Motor bottom
    • 34.4: Motor top

    Thanks -will check and let you know the outcome!

  • ectofix

    April 30, 2020 at 7:51 am

    WOW! I guess the Mayor doesn’t sleep!

    Anyway, here’s what I just wrote while, somehow, you two were talking at four o’clock in the morning (my clock says 7:45am).

    Yes, it is unfortunate that some Rational service codes will show a suffix code that’s not listed in the manuals. My understanding of that is, in such a case, the computer detects more than one issue related to the main code and thus displays some arbitrary suffix code that’s subject to interpretation.

    Anyway, the main code is 34, which is a bus connection issue. It could be due to:

    • A faulty RJ45 connection likely due to corrosion. The first connection I always check is the one to the main PCB (back of control panel), since steam from a leaky door seal can propagate corrosion there. If so, clean the connection points, then apply contact grease before plugging back in. That’s the same stuff that Rational ships with replacement boards and main blower motors. (NOTE: Do NOT use this grease on thermocouple connections).
    • A faulty bus cable. Maybe a damaged connector plugs or an internal short/open in the cable. For the latter, I have a cable tester for checking the cables. I suggest you keep spare cables in your truck stock.
    • Or a faulty component (main PCB, I/O board, one of the motors or, on gas units, ignition control). On more than one occasion, I’ve had a code 34 that was attributed to a faulty blower motor (Yes, even though there are separate codes for bad motors). Therefore, take the side cover off and check the two motor’s green LEDs. They should be illuminated and steady on. BTW: Check the main blower fuses behind the control panel too.

  • fixbear

    April 30, 2020 at 5:10 pm

    Thank you Mayor, and thank you Ectofix. I’m certain that this information will help several in the future with Rational’s.

    Ectofix, You posted a Fluke network tester. I have boxes of gold RJ45’s and a taster that has 4 receivers. But I wonder what wiring type that Rational uses. How are the pairs placed? And for accurate test I have to have at least a 12 ft run. So I have a coupler and a 12 ft coil I made to do testing. I did build a cat 5 in house network for a customer some years ago. Nothing like laying out and pulling 76,000 feet of wire alone.

    • ectofix

      April 30, 2020 at 7:27 pm

      I have absolutely NO experience in the communications sector. Just so happens that my boss allowed the purchase of that tester since our electronics guys had one, helped me by showing me how to use it and we subsequently identify a bad cable in a Rational oven. They also actually had a spare, off-the-shelf cable laying around which they gave to me and we got the oven going again.

      Since then, I keep the tester handy and also keep a spare cable in stock. The one I’d linked to earlier is one that Rational recommends because it happens to be their longest one. Rational has a TI (Technical Info bulletin) on that and also a TI on things to avoid when routing a bus cable to avoid damage to it.

      So far, the most prolific problem I’ve found with RJ45 cable connections has been the corrosion at the main PCB due to exposure to leaking steam.

      On Rational’s newer ovens (made since 2011), they got away from using RJ45 cables, favoring a much more dependable Molex-style bus cable.

      Unfortunately, those aren’t cross-compatible with the earlier ovens (2004-2011)…except for special ones supplied with their newer ignition controls for gas ovens.

  • holmanelectrical

    April 30, 2020 at 11:33 pm

    So, it seems that Comms Error – Service 34-“24″… but the 24 is actually the SUM of the two faults, so Top Ignition unit 8 + Bottom Ignition 16 + 24… this info from a Senior Tech here in Australia (thanks Graham!)

  • holmanelectrical

    June 7, 2020 at 9:42 pm

    So, the issue was resolved. We replaced both Gas Ignition modules (with latest version 87.00.577), replaced the Bus Cables 40.04.377 (comes with Ignition Box) PLUS a new Rational interconnection RASP-40.03.999 <i style=”font-family: inherit; font-size: inherit;”>Bus cable 1.50m (between the 2 new ignition boxes, Plus 1x new longer Ethernet Cables (we used a quality non-Rational Cable because we needed extra length to reach the bottom igniter. SCC201 running correctly now for 2 weeks… (Note we initially just changed the Bus Cables but this did not resolve the issue – but is worth trying first!)

    • ectofix

      June 8, 2020 at 8:33 pm

      Thanks for the update & info. Might be able to use that in the future.

  • stuartreiman

    July 16, 2020 at 4:49 pm

    Remember to use the contact grease they send everything except the Thermo-couples. Also, if you have alot of rationals in the area, also carry the latest steam hose (Black and comes with hose clamps). I do alot of work for Wal-marts and this is the biggest issue.

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