From: Charles W. <we...@no...> - 2001-07-03 12:32:36
|
There is a better solution to this problem than using two thermostats. What you are trying to build is the logical equivalent of the Leviton set-back thermostat. This unit is a standard set back thermostat that can be switched to set back via a dry contact switch such as an X10 universal module. If you set it to 90degrees and put the set back at 50 degrees you can turn your furnace off and on within thoses limits by just closing the setback switch( turn furnace off if hotter than 50) or opening the switch( turns furnace on if cooler than 90). This is a good idiot proof box for you program to play in. I like this better because it is an industry standard approach, can be installed by any heating guy comes with all the usual warrenties and does what I want. Of course it cost a bit more around $100 I think. > -----Original Message----- > From: Paulsen, Brian [SMTP:BPa...@le...] > Sent: Monday, July 02, 2001 5:09 PM > To: 'mis...@li...' > Subject: RE: [misterhouse-users] Re: multizone HVAC w/ iButton.com > > Right. It's because they aren't wired in series that it's a lot of extra > wire. If they were in series, it would be simple. > > As it stands, I have one run of wire that already exists. This is my > low-side protection. For high side protection, I think I have to run some > wire from the furnace/boiler to the thermostat and then to my relay board > and back to the furnace. For thermostat to do me any good, it would have > to > be put in the same room as the other thermostat. > > Brian > > > -----Original Message----- > > From: Mark Holm [SMTP:mar...@in...] > > Sent: Monday, July 02, 2001 4:55 PM > > To: 'mis...@li...' > > Subject: RE: [misterhouse-users] Re: multizone HVAC w/ iButton.com > > > > I hate to sound dumb, but why is it that much extra wire. The two > > thermostats should/could be side by side and they are wired in series > > aren't > > they? > > > > markh > > > > -----Original Message----- > > From: mis...@li... > > [mailto:mis...@li...]On Behalf Of > > Paulsen, Brian > > Sent: Monday, July 02, 2001 1:23 PM > > To: 'mis...@li...' > > Subject: RE: [misterhouse-users] Re: multizone HVAC w/ iButton.com > > > > > > You and Ian have both mentioned how I could protect myself on the "high" > > side. It's a good solution and one that should probably be used if you > > aren't 110% confidant about your code. The only problem with that > > solution > > is that you have to more thermostat cable to properly hook in the second > > thermostat. While that isn't a problem in most of my rooms, it > definitely > > is a problem in a few of them. With that said, I may bite the bullet > and > > figure out how to run wire to this second thermostat. > > > > Again, I don't mean to trivialize the damage that can be done by a "bug" > > in > > the code. If it's the furnace, you run a distinct possibility of doing > > damage ranging from melting things in your house to possibly blowing up > > your > > house. On the air conditioning side, you run the damage of breaking > your > > air conditioner, which can be fairly expensive. > > > > Brian > > > > > -----Original Message----- > > > From: Harald Koch [SMTP:ch...@po...] > > > Sent: Monday, July 02, 2001 2:26 PM > > > To: mis...@li... > > > Subject: [misterhouse-users] Re: multizone HVAC w/ iButton.com > > > > > > > The only issue I have is that if I have a bug in my code, there is > > > > nothing to turn the relay boards off, and the heat may get to an > > > > unbearably hot level. The only thing that can protect my there is > > that > > > > the normal state for these switches is to be open (i.e., circuit is > > > > broken) So, if I lose power when the relay board is supplying heat, > > the > > > > > > > circuit will get broken and the heat will be turned off. > > > > > > I've seen a circuit on a list or on the web that uses *two* > thermostats > > > in concert with computer control. One is low temperature protection; > the > > > furnace will *always* come on if the temperature drops too low. The > > > other is a *high* temp protector; it *always* breaks the circuit at > high > > > temperatures. > > > > > > If you use this, your computer can only control the boiler in between > > > the two thermostat settings, protecting you from "bugs in your code". > > > > > > I'll see if I can dig up the reference (it might even have been on > this > > > list), but it'll take a few days (my annual hard-disk juggling is in > > > progress). > > > > > > -- > > > Harald Koch <ch...@po...> > > > > > > "It takes a child to raze a village." > > > -Michael T. Fry > > > > > > ________________________________________________________ > > > To unsubscribe from this list, go to: > > > http://sourceforge.net/mail/?group_id=1365 > > > > > > > > > > -------------------------------------------------------------------------- > > -- > > -- > > This message is intended only for the personal and confidential use of > the > > designated recipient(s) named above. If you are not the intended > > recipient > > of this message you are hereby notified that any review, dissemination, > > distribution or copying of this message is strictly prohibited. This > > communication is for information purposes only and should not be > regarded > > as > > an offer to sell or as a solicitation of an offer to buy any financial > > product, an official confirmation of any transaction, or as an official > > statement of Lehman Brothers. Email transmission cannot be guaranteed > to > > be > > secure or error-free. Therefore, we do not represent that this > > information > > is complete or accurate and it should not be relied upon as such. All > > information is subject to change without notice. > > > > > > > > ________________________________________________________ > > To unsubscribe from this list, go to: > > http://sourceforge.net/mail/?group_id=1365 > > > > ________________________________________________________ > > To unsubscribe from this list, go to: > > http://sourceforge.net/mail/?group_id=1365 > > > > > -------------------------------------------------------------------------- > ---- > This message is intended only for the personal and confidential use of the > designated recipient(s) named above. If you are not the intended > recipient of this message you are hereby notified that any review, > dissemination, distribution or copying of this message is strictly > prohibited. This communication is for information purposes only and > should not be regarded as an offer to sell or as a solicitation of an > offer to buy any financial product, an official confirmation of any > transaction, or as an official statement of Lehman Brothers. Email > transmission cannot be guaranteed to be secure or error-free. Therefore, > we do not represent that this information is complete or accurate and it > should not be relied upon as such. All information is subject to change > without notice. > > > > ________________________________________________________ > To unsubscribe from this list, go to: > http://sourceforge.net/mail/?group_id=1365 |