Cm101 oven

[olivero]

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]

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]

Right. My bad.

[olivero]

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]

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.

 

PROBLEMS:

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.

 

MAINTENANCE:

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]

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]

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]

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]

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]

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.