The Wall
Forum / THE MAIN WALL / isolation relay?
  • Post a Reply to this Thread

    isolation relay? (19 Posts)

  • rucomfy rucomfy @ 7:05 AM
    Contact this user

    Thanks for that advice on three wire connections. It will will make it alot easier to understand. How can I get a copy of that schematic so I could laminate it for my service library ?? Thanks again, nice, very nice...
  • N/A @ 10:07 PM

    Pat,

    > I need a simple solution to isolate two 24 volt
    > transformers. Existing taco zone valves with Lux
    > programable t-stats - new boiler with a R8285D
    > control center. Boiler runs fine when R-G jumped.
    > Zones valves work and wired correctly. When end
    > switch on taco zone valve terminal 2-3 are
    > connected to R-G transformers fried as zone
    > valves opened. All I can think is that I'm
    > getting some stray voltage on taco 2-3 circuit.
    > Transformers phased etc.. What can I use to
    > isolate the two circuits. Thanks inadvance for
    > your help.

  • N/A @ 10:09 PM

    Pat,

    I have the solution for you. Call me at 401-437-0557 or e-mail at gastc@cox.net. This happens all the time when wiring with the R8285 Control Center. It just so happens I have exactly the diagram you need. If you have a fax I can fax it to you or I can e-mail it.
  • N/A @ 10:11 PM

    rjbphd

    I can send you some info on wiring Taco ZV's get in touch with me 401-437-0557 or gastc@cox.net
  • N/A @ 9:03 PM

    This is NOT for everyone Tim!

    The diagrams you sent me are for an R8285D that is specified for one particular model Weil-McLain boiler. That transformer can be used to power the zone valves because, as configured, it has enough capacity to do so. As I specified in post above, we do NOT want the zone valves powered from the R8285D on the boiler. As I also stated, there are literally thousands upon thousands of installations with Taco Zone Valves and all brands of boilers that are equipped with the R8285D transformer that do and have always operated well because they were wired correctly. Unfortunely mistakes do happen and need to be corrected. Everyone out there also has to realize that there are literally scores of different R8285D transformer relays out there as specified for particular equipment manufacturers equipment. For this reason we ask that you follow the guidelines provided by Taco and for our product and if done correctly, will work just fine! Glenn Stanton Manager of Training Burnham Hydronics U.S. Boiler Co., Inc.
  • Pat Pat @ 10:50 PM
    Contact this user

    isolation relay?

    I need a simple solution to isolate two 24 volt transformers. Existing taco zone valves with Lux programable t-stats - new boiler with a R8285D control center. Boiler runs fine when R-G jumped. Zones valves work and wired correctly. When end switch on taco zone valve terminal 2-3 are connected to R-G transformers fried as zone valves opened. All I can think is that I'm getting some stray voltage on taco 2-3 circuit. Transformers phased etc.. What can I use to isolate the two circuits. Thanks inadvance for your help.
  • Joe Mattiello Joe Mattiello @ 4:00 PM
    Contact this user

    Taco, zone valve operation.....

    Perhaps I can clear the air a little. Attached is a technical bulletin that was drafted in 1988 to address previous concerns by the dead men. The wiring of the heat coil type valves has been the same, and consistent since they were introduced approximately 50 years ago. Terminal 2 is two fold, one half is the power side of the valve, and the other half is the isolated end switch. OK, so if we only use one side of the end switch then we can not draw smoke from the transformers. The other concern is the VA required. If you do the math volts X amps = VA required, or 24 volts X .9 amps =21.6, Taco advocates 3 valves per 40 VA transformer, or 64.8 required. Most people call scratching their heads. I like to think that's job security, but the truth is the valve is intermitting so it does not require a constant draw. Hopefully this helps. If you have additional questions or concerns, give me a call, I will be happy to talk with you. Joe Mattiello Technical Support Engineer Tel. 401-942-8000 X 484 Fax. 401-942-2360 1160 Cranston St Cranston, RI 02920 joemat@taco-hvac.com
    joe mattiello
  • N/A @ 12:26 AM

    Pat

    I have seen this countless times in the field and in every single instance it has been miswired zone valves that were wired with 2 conductor red and white tstat wire. Rather than attempt to trace out the rats nest of red and white wires I have always found it easier to simply yank it all out and start over the right way with 3 conductor wire. As you know, we have the diagrams for this in our books. Call me on Thursday about this....you know my number! Glenn Stanton Manager of Training Burnham Hydronics U.S. Boiler Co., Inc.
  • N/A @ 3:34 PM

    anybody?

    Anybody have Glen's number? I could use this book on wiring the taco valves, I get it right on one job, next job....blanked mind... Thanks for helping, Glen....
  • Empire Empire @ 9:08 AM
    Contact this user

    Glen

    I to am just a little confused on this valve. I see where it can be connected to T T on some boiler controls, but when I look at the additional t-former and wire according to diagram as per taco,...I see problems. I'm sure I am wrong, but need clarification. Even in the wiring diagram it states that the 2 are separate circuits, but if you pass 24 vac onto term # 3 and when the contact closes isn't that a direct short to ground via the other t-former? I am the kind of tech that gets frustrated when I cannot understand in 5 min......;-) or less..... Thanks Mike T.
  • EBEBRATT-Ed EBEBRATT-Ed @ 6:40 PM
    Contact this user

    After looking at the diagram on the Taco web site I understand how this will work with two transformers. However IMHO this is a poor set up. Not only is this setup a bear to troubleshoot (you will always have backfeeds to contend with between the transformers) but it is very confusing when out on the job without any paperwork which is usually the case. Face it, the end switch is not a clean set of contacts IMHO. The solution is to use a seperate relay pulled in by the zone valve end switch. Then let the contacts of this new relay start the boiler. If I was manufacturing this valve why not bring the end switch wires out of the valve seperatly (a 4 wire valve) 2 end switch wires and 2 to power the valve. Much easier to troubleshoot and you wouldn't need any diagram to figure it out! Ed
  • N/A @ 6:54 PM

    3-wire zone valves

    This has been a problem that has existed since the 1970's when they were brought into the market. But people have become accustomed to them and are used to the ways that they need to be wired. Newer models such as the EBV or Electric Ball Valve type of zone valves from Taco are 4-wire and do indeed have dry contacts for the boiler thermostat (call for heat) circuit. Since day one, as far as I recall, the 3-wire models have come with a yellow card attached to the head that shows the way they should be wired. Unfortunately they somehow get yanked off before the person doing the wiring gets there.For that reason we have include zone valve wiring diagrams in our gas boiler I&O manuals for as long as I can remember. They cover all types and brands of zone valves. Here is one out of our Series 2 I&O manual. Hope this helps. Glenn Stanton Manager of Training Burnham Hydronics U.S. Boiler Co., Inc.
  • EBEBRATT-Ed EBEBRATT-Ed @ 8:32 PM
    Contact this user

    I don't think this setup will work without shorting. Your zone valve wires #2 & #3 need to pull in a relay coil. You already have transformer power from the transformers that are powering the zone valves. The R8285 has it's own transformer to power it's own relay coil. Putting a switch (or a jumper) between R & G will pull in the relay and operatet the boiler. R & G need relay contacts to work. The fix is to add a 24 volt relay with the coil pulled by wire 2 & 3 from the zone valves. Wire NO contacts from this new relay to R & G. Use a Honeywell R8225A1017 or a RIB relay. Ed
  • Empire Empire @ 8:34 PM
    Contact this user

    Glen....

    I appreciate all you input. I think if nothing at all comes from this discussion, Taco and any other manufacturer needs to,...how can I say this,...at the least simplify the wiring diagram ESPECIALLY when only 1 scenario is given. I think if there were a few different boiler controls depicted, I for 1 would get the picture. Almost like trying to figure out a bypass unloader without the manuals. Unless you know the set up, you surely get frustrated. Come on TACO add another piece of paper with at least 1 or 2 more depictions of how it works...;-) Mike T.
  • N/A @ 8:13 PM

    Glenn I e-mailed you

    the diagrams for wiring TACO ZV's with R8285 control. For everyone here the simple solution for this problem is when using two transformers do not parallel connect them. Isolate each transformer and then follow what seems to be a backward way to wire to the R8285. You go from the "C" terminal on the R8285 to each thermostat then to terminal "1" on ZV. "R" from 8285 then goes to "2" on the zone valve. "G" then goes to "3" on the ZV.
  • N/A @ 10:07 PM

    Pat,

    > I need a simple solution to isolate two 24 volt
    > transformers. Existing taco zone valves with Lux
    > programable t-stats - new boiler with a R8285D
    > control center. Boiler runs fine when R-G jumped.
    > Zones valves work and wired correctly. When end
    > switch on taco zone valve terminal 2-3 are
    > connected to R-G transformers fried as zone
    > valves opened. All I can think is that I'm
    > getting some stray voltage on taco 2-3 circuit.
    > Transformers phased etc.. What can I use to
    > isolate the two circuits. Thanks inadvance for
    > your help.

  • Empire Empire @ 8:54 PM
    Contact this user

    EB

    I agree but I think in the diagram the Taco drawing is lacking in representing what control EXISTS at the bottom left of the pic. I hate that. If It were TT....OK It would work, but I think the T-Former you and I see from the boiler is Internal to the control., not as shown. They do not specify!!!! One more thing....Stuff like this makes me want to go with H.W. valves or the like. I don't have time to call the rep/ Waite for a return call and all that crap!!!!!. W.R had the same problem with their 3 wire valves, till they lost sales because it was like a mind bender until you understood the concept. Joe Mattellio,..Chime in at any time here.....;-) To Taco,.....To this day I have not purchased any of you Heat reactive zone valves or what ever you call them.. Let's see....about 8 valves a month X sales = "0" for the Taco valve. Man I am frustrated. Pat Try Taco.com where I got this document and they should have a contact # directly for you to have your question answered. While you on the phon ask them why it is not perfectly clear as to the wiring if you can., We have 3 people here that need answers and that would be great. Hopefully it's not a trade secrete.....;-) Mike T.
  • N/A @ 10:14 PM

    Mike T, TACO does

    not know about this wiring difficulty as it is related to using the R8285 Control. This has come up numerous times here on the Wall and I have made the diagram I worked out years ago to solve this problem available and it works everytime.
  • N/A @ 6:13 PM

    Tim

    No disrespect intended but I'm going to have to take you to task on some of your comments above. This problem is not just relative to the R8285D relay and does not happen all of the time. There are literally thousands upon thousands of installations out there that have had no difficulties whatsoever. Taco as well as other control manufacturers are aware of the possibilities of bucking transformers if valves happen to be miswired. Why do you think that they developed and sell so many of their ZVC Zone Valve Control relays? The problem I see happen most often is simply crossed polarity of the current being switched from the external zone valve transformer through the second or third thermostat to their respective zone valve. If the first zone is switching the hot of 24v through it's thermostat onto terminal #1 of its zone valve but somehow the second zone is switching the neutral leg of 24v to Terminal #1 of it's zone valve, then the polarity is now crossed. All of the Taco 3-wire valves will have the #2 terminals bridged together as well as all of the #3 terminals bridged together. The wires from #2 and #3 go to the boiler control to switch the leg of 24v hot being sent out of the boiler transformer through the #2 and #3 zone valve end switch and back to the boiler relay to establish a call for heat. The #2 terminals also connect to the neutral leg of the external zone valve transformer. If one of the zones has crossed polarity for any reason as described, then it is usually the boiler transformer that loses the polarity battle. I have provided a drawing of the proper way to wire the valves. As I stated above, when the person wiring the zone valves uses only 2 conductor wire, it becomes rather difficult to trace out the problem. I always advise using 3 conductor wire so that all of the #1 terminals get a red wire, the #2 terminals a white wire and all greens for #3. This makes it easier to trace things out and to keep polarity straight. Also never try and use the boiler (R8285D) transformer to provide current for your zone valves. It is neither strong enough nor intended for this purpose. Glenn Stanton Manager of Training Burnham Hydronics U.S. Boiler Co., Inc.
  •  
Post a Reply to this Thread