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  • Cm101 oven

     olivero updated 3 years, 7 months ago 1 Member · 19 Posts
  • guest

    November 2, 2016 at 12:00 am

    I just bought a set of heating element which consist :

    1) Inner heating element

    2) Outer heating element


    before replacing the element i did a continuity test and found both heater has continuity reading. 

    Is this normal ? Is there any explanation ?

  • olivero

    November 2, 2016 at 1:09 pm

    Well, Its a heating element, heating elements are really just insulated pieces of conductive material with a certain resistance put into it to give you a certain amount of heat. as electricity generates heat in general, the higher the resistance the more juice its pumping through that conductive material and it gets hot.


    That’s why you can only draw so many amps on a wire as it will overheat and melt in half if it gets too hot, there is not enough surface to carry the load, in this case, its intentionally done that way so that the element, heats.


    So the fact that its got continuity means that its not broken somewhere (which is good), what the ohm reading is, is what matters. If you are worried about something then just call Rational and ask them what the resistance reading should be in the element and compare.


    IT can happen that the element starts deteriorating which makes your ohm higher or lower depending on what’s happening, normally the element will short and your ohms will be 0 or 1 which is pretty much a dead short and it wont heat OR you have 0L which means there is no continuity at all and the conductive material broke somewhere.


    I could keep going but I think I answered your question. Most elements are 30-60 ohms or at least the few I have.

  • ectofix

    November 2, 2016 at 6:15 pm

    olivero wrote:


    Well, Its a heating element, heating elements are really just insulated pieces of conductive material with a certain resistance put into it to give you a certain amount of heat. as electricity generates heat in general, the higher the resistance the more juice its pumping through that conductive material and it gets hot.

    Sorry to attempt to correct that.  Maybe it’s the way you wrote it.


    Actually, what you said is the opposite.  The higher the resistance, the LOWER amount of juice (measured in amperes) that’s pumped through…under the conditions of the same applied voltage.


    Remember the magic circle.

  • olivero

    November 2, 2016 at 8:40 pm

    Right. My bad.

  • olivero

    November 2, 2016 at 8:41 pm

    I have been trying to get a good opinion on Rationals oven in terms of service, how are they? Do they break down a lot, require a lot of maintenance? Trying to find a good one for my kitchen.

  • ectofix

    November 3, 2016 at 5:52 pm

    I thought AltoShaam was the one.  They (and you) are still searching?


    I’ve not seen Rational’s NEWEST gas units (SCC 5 Senses).  Our three new ovens are that…and electrically heated instead of gas. 


    Referencing GAS units, we DO have seven of the older gas SCC ovens (made 2004-2011).  That SCC platform IS the basis for the 5 Senses, but I think most of the internal components in the SCC 5 Senses are different from the original SCC.


    By the way, SCC is what Rational calls the Self Cooking Center.


    Problems and maintenance?  Of the seven gas ovens, ONE is a 202.  The rest are counter-top units of various sizes.



    In the SCC-202 unit, the gas train has been its biggest problem.  I’ve replaced several ignition modules, burner blowers and when I was in over my head with a chronic problem, an outside service company deemed the lower air heat exchanger was cracked.  Subsequently they replace it and all components back to gas and electrical inputs to that particular burner system.  That was nearly a year ago.  No problems since.

    I’ve not had these same problems with the other gas units.  Maybe a faulty ignitor or two…and, well…an ignition module in another.


    Other problems?  Water solenoid valves.  For the ovens’ cleaning systems, I’ve gone through a few pumps here and there.  Can’t think of much else.  ELECTRICALLY, they all are solid.  Only if steam or moisture became a contributing factor did I have any problems there.  There wasn’t many.



    VERY minimal.  I absolutely LOVE their Cleanjet with Care Control feature.  I ride the Chefs to feed the ovens its pills (cleaning tablets) regularly.   Two of our newest oven are pushing a year old now and haven’t needed to to descale them yet.  Our third newer oven is only two weeks old, but I expect the same from it.

    I think you told me that’s not a problem in your area?  Well, it’s a big problem here.  So the self cleaning feature has been a blessing.


    Otherwise, for other regular upkeep, I just gotta keep an eye out for loose door hardware, cracked door gaskets and such.  Not much to complain about.

  • badbozo2315

    November 3, 2016 at 7:14 pm

    Rational has dumped the old we/white effiency and 5 senses monikers. Now only (back to) Self Cooking Center.

    Newest series is XS, new software, version 7.

    Basicaly the working guts of the older series, doors now have 3 panes of glass.

    There is a killer small unit, 24 inches wide, tabletop, electric only. Looks to be a killer at $11,000 list. Uses a smaller fan motor, but otherwise is a mini scc. Water, drain, pre attached electric cord with cordcap, directly at REAR not underneath!

  • olivero

    November 3, 2016 at 9:37 pm

    Cool, I am always looking for new feedback. We are as of right now, going for the CTP 20.20G from Alto Shaam, seems like they got a very solid support team at Alto Shaam which Cleveland lacks hardcore and the oven is just great but despite all the flair the vendors show I care more about the ovens operation and maintenance needs as that’s really a main factor when you cook for 2500 people morning, lunch and dinner every day of the week. The chefs here are cooking all day long so when the oven goes down, I got to get it back up as fast as possible.


    Thanks for the rundown though. Where do they make the Rationals? In germany?

  • badbozo2315

    November 4, 2016 at 5:17 am

    I just installed a ctp 10-20g earlier this week. As long as you have good access to the left side (mind that 2-ton side cover) access to parts is great.  Open and accessable. Computer access at the front is so much better than everyone else. Don’t know how the spritzer steam generator will work out though, even with the filter/treatment system they installed.


    Yes, Rationals are made in Germany.

  • olivero

    November 4, 2016 at 8:29 am

    Cool, I am pretty excited about it. Should hopefully be much better than what we got.


    What is the computer access on the front?

  • ectofix

    November 4, 2016 at 5:09 pm

    I maintain Rational ovens all day long…and I’m  lost on this one.  A serial number and a rated voltage REALLY would’ve helped.


    Two things:

    • Rational made CM (CombiMaster) ovens throughout all of their four model-lines…dating from 1986 and up until 2011.  Then they changed it to a CMP (a Plus on the end).
      • Pre-2004 may have had separate inner and outer hot air heating elements.  I don’t know, because I don’t have one that old.  Nonetheless…if they DID, then any given element would ohm as a 3kw element.  Element resistance varies – based upon rated input voltage it’s designed for.
      • From 2004, the hot air element in a 101 is a single assembly comprised if six heating elements – each rated at 3kw.  However, elements are pre-wired in a Y configuration with just four input leads.  So reading resistance of the ASSEMBLY is like reading through two elements connected in parallel.  If it’s a 480v element, the resistance reading would only be down around 10 to 15Ω.
    • Check your usage of your meter.  If you have a digital meter like a Fluke and you’re using the continuity feature that BEEPS when there’s continuity, STOP that.  The beep will occur at resistances as high as 20Ω.  SO…if you’re testing an element ASSEMBLY comprised of six elements in parallel, the resistance will actually BE less than 20Ω
      • Just use the resistance setting and read the resistance value, then do the math.


    Do you know the math?  If not, then I’ll give a quick dissertation on how to do that.  Just respond back and I’ll follow through.

  • badbozo2315

    November 4, 2016 at 5:46 pm

    Isn’t that just the goofiest place for a usb stick port? However, I can show you several Chicken Fillet Garland clam grills with covered usb ports right on the front that are damaged and or filled with butter and grease and gawd knows what. I always take off the panel and go right to the control computer to update software.


    Truthfully I don’t know on the new small one. Big ones are still on the bottom.  We got the sales pitch this first go round. Soon we get the tech info.


    >What is the computer access on the front?

    On the Alto or the Rational? The Alto is perfect. 1 phillips head screw at the top releases a catch, computer lifts out and hangs on brackets.

    On the Rational, I think I remember hearing something about not needing a hex key to get to the computer, and it hanging like an Alto with great access.


    We went to install a 61E at a Hooting place earlier in the week. When we got it unboxed, I’m like wtf? No we or 5 senses, but what’s an Self Cooking Center xs?

    Fat, dumb and happy, I stick in my 6.0.081 usb update stick, light her up, and the oven goes, like, no thanks. We checked the existing software and it was 7.something.


    Then we got the webinar intro pitch the day after.  Go figure… 

  • ectofix

    November 4, 2016 at 8:08 pm

    Maybe he’s speaking of where the USB stick can be inserted for HACCP data, downloading/uploading recipes, etc.


    Unfortunately, Rational’s USB port is UNDER the front-left panel (like—under the oven!).  Looks like AltoShaam put theirs in a far more logical, user-friendly location.  Right by the control panel.

  • ectofix

    November 8, 2016 at 5:57 pm

    olivero wrote:


    I care more about the ovens operation and maintenance needs as that’s really a main factor when you cook for 2500 people morning, lunch and dinner every day of the week. The chefs here are cooking all day long so when the oven goes down, I got to get it back up as fast as possible.


    Heck olivero, it sounds like you work at a place like mine.  We won’t name names of where we work though.


    Our banquet kitchen has four 202 combi-ovens abreast (and they want a fifth) and a set 101 counter top ovens.  Each group of combi-ovens book-end a cook line occupied by several tilt skillets, multiple large steam kettles (and a small one), a VERY wide griddle and miscellaneous GAS-fired stuff.  A double-stacked set of 480v Boldgetts and a Hobart floor mixer (HL1400 for doing their mashed taters) are excluded from the necessity of hood coverage.  All that faces AMPLE stainless steel, casterized tables, 480v bain-maries and a fleet of banquet warming cabinets awaiting their loads of hot food for transport to their assigned event halls.


    If I happen to have the time on a given day, I might pop my head in there to look things over to ask about any problems…and also ask “How many you feeding TODAY?”


    “3000 for lunch.”


    “Oh…well if I get in the way, let me know.”


    Usually that would be an abbreviated visit and I’d just dance my way outta there to dodge everyone scurrying about.  I REALLY don’t want to be there when it’s that crazy. 


    Here’s those 202s over about a year ago.  The twenty-two year old behemoth on the left (a Rational CCC-202) is now retired as a back up.  It was recently replaced by a new one like the two on the right.


  • olivero

    November 8, 2016 at 9:15 pm

    Aint bad, aint bad at all.


    Sure sounds similar, we got more tilt skillets and kettles than we do Combis currently, got 2, 72″ flat tops, 3, 30 something ”  grills, 1 doulbe deck cleveland steamer, 3, 100 gallon steam jacket kettles 1 with the agitator and 3, SGL-40 tilts thats the hot part of the kitchen as well as 2 cleveland combis and 1 double deck vulcan oven and 1, 3 bin Frymaster deep fryer with their fancy filter system. Got another 3 sections but that’s the main.


    Looks like i am not the only one with the problem of the hood being too short to reach the door of the oven… so annoying, considered building and welding in a small canopy type hood SPECIFICALLY for the combi, but figured some things might move in the future and it would be messed up then.


    Well, one thing I am a big fan of is cool designs, Alto-Shaam’s got that cool handle that’s LED lit which really got me lol.


    Are those units 366K BTU?

  • ectofix

    November 9, 2016 at 6:56 pm

    olivero wrote:


    Aint bad, aint bad at all.


    Are those units 366K BTU?

    You made me look at spec sheet.  Rational rates everything in KW.  Even our gas units.


    AltoShaam rivals Cleveland’s old Convotherms in terms of heat production.  AltoShaam exceeds all present-day competitor’s models though.

    My Rational 202s are rated for 62KW, which is about 212K Btu.  AltoShaam is the big dog in the market for heat production at 266K Btu (not 366), which equals to around 72KW.  Most other competitors fall short of Rational and AltoShaam in that comparison.




    You mentioned a mixer kettle. That sounds almost industrial-strength.  That is a realm of food service that I was not familiar with before I started working here five years ago.


    We have a completely separate facility on property that does LARGE scale food preparation…as ordered up by the restaurants.  Soups, stews, par-cooked or smoked meats (slices, diced, shredded or NOT), salad-like food stuff, breads, rolls, desserts and I-don’t-know-what-else.  Delivered daily in refrigerated trucks in bags/pans, on pallets or speed racks – to meet each restaurant’s needs for that day.


    This building includes:

    • A hot kitchen – with two behemoth Enviro-pak smokers, three 100 gallon Cleveland cook/chill mixer-kettles with metered filling stations (food pumpers), a Cleveland tumble chiller, vacuum sealers, MANY slicers… and other run-of-the-mill cooking appliances.   FACTORY-sized walk-ins EVERYWHERE (to accommodate forklifts) and several roll-through blast chillers.  Their W/I freezer could enclose my two-story HOUSE…with room to spare.
    • A cold kitchen – with some vicious and noisy veggie dicing and meat shredding devices (made by Urschel) that rival large chipper/shredders for their intensity.  Floor food processors of every kind. They also have their own butcher shop…with all the equipment which that entails.
    • A bakery – ran by a French Chef who (for some reason) prefers every machine they use to be one he ordered from Europe (except the fleet of old Hobart floor mixers).  I think he only shops from the Gemini Bakery Equipment Company catalog.  Spiral mixers, various dough sheeters and formers, scales (apparently a MUST in a bakery), four Sveba-Dahlen rack ovens, a Wachtel deck oven, a roll-through proofer, numerous bread or dessert cutters and slicers. Their ever-important item is the Werner and Pfleiderer (WP) Miniroll production line.  That monstrosity is like a printing press for making thousands of perfectly formed dinner rolls a day.


    That “facility” is quite the challenge when compared to what I formerly did a field service tech.  Food-factory-like (mass production) equipment was NOT where I “cut my teeth” in my first fifteen years of doing this stuff.  Forms of energy abound as well.  Not just the typical electrical or gas-fired cooking equipment.  480v is everywhere.  90 psi live steam is predominant too…and pneumatically operated stuff.  



    • Computer touch screens (just replaced a VERY expensive one of those in a meat smoker today). 
    • PLCs.
    • VFDs.
    • PIDs.


    All that are types of controls that’s new terminology for me.  Some requiring reference to the digital realm of electrical training from a college class I blasted through twenty-five years ago (in my thirties) – that is only vaguely helping me with TODAY.


    But we learn (re-learn) as we go.  I guess I’ll never get bored (unless I retire)…since new conquests present themselves QUITE frequently.



    OH…and for some semblance of keeping on topic.  They have three 202 combi-ovens there in that “facility”.  The two in the hot kitchen pre-cooks ALLOT of bacon for the restaurants.  I never paid attention to what else.  I just like the bacon.


    I think the bakery uses their one 202 for small orders of cheesecake or whatever.

  • olivero

    November 9, 2016 at 7:04 pm

    HAha, sounds like quite a plce indeed. I guess we do have that in common, we got our hands full


    I have been working on walk ins all day today, no fancy screen changing for me but I appreciate the information on the ovens Really want to make sure I get the best one for this kitchen, tried of having problems with them.

  • badbozo2315

    November 9, 2016 at 8:30 pm

    I still say, I don’t know how you sleep at night, 2nd shift help or not. 


    I do miss all that bakery equipment with your french chef. Something magical about silos of raw flour, yeast, heat and time. The smells of fresh hot bread…

  • olivero

    November 9, 2016 at 8:38 pm

    We got a bakery here too, love doing work in there. Smells sooo good.

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