From: muratlanne@gmail.com   
      
   "David Billington"  wrote in message news:10nic1b$39582$1@dont-email.me...   
      
   It occurred to me when I was posting that last reply that you have to   
   deal with your electrical energy budget issues and that might make you   
   favour a different solution if available, not something I have to think   
   about so much with a 240V 32A supply in the workshop, more in the house.   
      
   Looks to be a nice furnace but what you have must be a lower temperature   
   model. 1500C would likely be a Mullite liner and SiC elements. AIUI SiC   
   are fairly easy to control with a phase angle controller and take care   
   of the change in resistance while heating and element ageing.  MoSi2   
   elements get more involved due to their characteristics  but not   
   required for 1500C usage.   
      
   I'd not heard of type P before as never run across one. Here in the   
   UK/Europe R and S are common for higher temperature applications, it   
   seems often US made stuff uses larger gauge K type to provide longer   
   life at elevated temperatures. For the Gallenkamp I use a K, the other   
   furnace I have an N type as more durable at the higher temperatures I   
   may have been using as that one goes to 1300C or would do if I replaced   
   the elements as they're old but it does what I require currently and   
   will make 1100C if needed.   
      
   Reseating socketed chips is one I use as well. I've saved a woman I know   
   quite a bit of money as when one of her temperature controllers gave a   
   thermocouple failure alarm I asked if she had pulled the guts and   
   reseated them, she wasn't aware you could do so RTFM. Others offered to   
   sell her a replacement. The Cal Controls ones I and she use and maybe   
   other makes allow the guts to be pulled from the panel mounting which   
   wipes the contacts and they had just become oxidised as only solder   
   coated so that was all that was required to get it working again, it's   
   now part of her yearly service routine. I've seen banks of them on   
   plastic extruder lines so the ability to hot swap the controller guts is   
   useful, saves having to pull the panel apart. IIRC those were on RS485   
   so the settings could be re-established remotely.   
      
   ---------------------------   
   I have 200A at 120/240V available if I want to pay for it, this house was   
   built with electric heat for the promised cheap nuclear power we would soon   
   enjoy. My retirement hobby is alternate energy and I practice living on it   
   as much as is reasonable, and recording the usage.   
      
   The tube furnace may be the lower temperature model, labels are gone. I   
   grabbed the first picture I saw. The missing original controller was   
   apparently analog with optical sensing of the needle, and calibrated for   
   type K, so the P t/c is a close but not exact match. Like much of my stuff   
   it's from the 1960's.   
      
   All my (second-hand) industrial temperature controllers can be removed from   
   the panel mount, mostly to change switch settings such as t/c type. I use   
   some as remote displays of the wood stove. The surplus store sold regular   
   wire cheaply by the pound, t/c wire expensively by the foot. When I   
   explained that the X meant extension wire not suited for making   
   thermocouples they gave me the per pound price on several large spools of   
   shielded and grounded KX which isn't good for much else, and I ran it around   
   the house.   
      
   Omega literature suggests using 14 gauge type K for longer life at high   
   temperature. I think R and S are more for short runs within the instrument   
   in the lab.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)