Need HVAC Advice

Discussion in 'Off-Topic' started by jpanhalt, Sep 6, 2015.

  1. jpanhalt

    Thread Starter AAC Fanatic!

    Jan 18, 2008
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    I am posting off-topic as this is electrical, not electronic. My home has a multi-zone hydronic heating system, which is a ratsnest of wires:
    V4043 valves_W-R 829A relay_sm.jpg W-R 1311 Zone Valves_sm.jpg

    I have wanted to clean it up the wiring, just because that is me. However, there have also been problems, so now seems like a good time to do that. Here is a schematic I think is pretty close to reality. I simply labeled every wire I could find and traced them out: see pdf attached below. The most recent problem was traced to sticking of the W-R 829A relay, which led to the circulating pumps running almost continuously just to provide domestic hot water. I filed the contacts and pried them apart a little, which seems to be working while I await my replacement relay.

    Questions:
    1) I was worried about phasing the low-voltage transformer in the 829A relay with the transformer that supplies two main zone valves (W-R type 1311). However, as I looked at the schematic of that valve, it does not appear that is the case. Please say if you disagree.

    2) As I clean up the wiring, which is currently done with 2-wire thermostat cable, is there any recommended or required color code? I won't change form the current red and white system just for change; however, the wiring to the main zone valves could be cleaned up by using cable with more wires and colors.

    3) One contributor to the problem just mentioned was a loose wire in a crimp connector to the Honeywell R8222D relay. I am not a big fan of using crimp connectors on solid copper wire. Is that the usual practice, or is it acceptable to use an uninsulated connector with solder?

    4) The remote fired hot water tank is a Weil-McLain Gold Plus 30 from about 1993. It is in a rectangular metal cabinet. The thermostat wiring is pretty straight forward. However, I am less clear on why it is wired to the boiler the way it is. Does anyone have the internal wiring diagram for that that water heater? I have checked the W-M site without luck

    Regards, John
     
  2. JoeJester

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  3. #12

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    That's because they don't work.
    I am amazed at some of the plumbing trade crimpers that make water tight seals on hard copper pipe because there is very little springiness there. I have never seen an electrical crimp on solid core that was reliable. You can solder to a naked crimp connector. You can use wire nuts. You can catch one (1) wire under a screw without violating Code.

    The standard practice is:
    Red = 24 VAC
    Green = Fan
    Yellow = compressor
    White = heat
    Blue
    Orange

    Blue and orange are for flammable fuel furnaces that rarely get used in Florida. One is for a fan and one is for a change-over valve, but I obviously don't know for sure. One of them is only 'hot' for heat and the other is only 'hot' for cool. Lacking fuel burner furnaces, we often use blue or brown for Common on a complicated job. Waitaminit. Where did brown come from? I dunno. I find it in the cable and somebody used it for Common. One of the first things you do on a new job is pop open the thermostat and count wires. If there is more than 4, make a schematic and figure out who is Common.
     
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  4. jpanhalt

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    Jan 18, 2008
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    I had the second manual. I did not have the first, and it has some information that might be helpful for future problems. Neither explains the four wires interconnecting the heater to the boiler. In particular, I cam concerned about the Red and Black wires that come from the boiler low-voltage transformer.

    The two thermostat wires (colored red and black) are marked RT6 and BT6 in my sketch -- those labels were simply my way to keep track of the wires. When disconnected from the rest of the system, there is no voltage on them, so I have assumed they are in a conventional thermostat arrangement with the other low-voltage transformer and Honeywell relay. The two wires labeled BL (blue) are contiguous with wires in the boiler that are spliced to black and then connect to the wires from the Aquastat and terminals X1 and X2 (millivolt or auxiliary) of the W-R829A relay. That relay also controls the circulator pumps with another set of contacts. One possibility is that the two, low-voltage wires (i.e., R and B from the boiler) are provided for other types of installations, but are not needed in mine. I could disconnect one and see what happens when the boiler is running, but I would rather get a more knowledgeable opinion first. The wires themselves don't bother me. I am just worried about putting two low-voltage transformers accidentally in series, rather than parallel.

    John
     
  5. jpanhalt

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    #12

    Thanks for the color code. I found similar versions of that, but there seems to be some inconsistency.

    Some call the red wire common; others call it the "hot" wire and then call the black (alternatively brown, white, or blue) the common. By "hot", I think they are referring to the wire I have dotted in my diagrams to denote the phase. None of the secondary wires on the transformers are connected to a grounded wire equivalent to a household common (N) wire.

    Some of the transformers in my house have both a red and white wire on each terminal. I think the convention of red for hot and the other colors for switched or heat call makes sense. I just wanted a little more consistency for the wires from the transformer and will stay away from yellow, green, and orange. I will limit the use of black to those instances where the device is pre-wired that color. Since it is all low voltage and there is no grounded wire, it probably doesn't matter much.

    You mention putting one wire under a screw and staying within code. In my house, there are several instances in which two or three low-voltage wires are under a screw. I am in an unincorporated area so codes are relatively unimportant, but if more than one wire under a screw is not code, I will be sure to change those to spades, or do you have to use a terminal block?

    John
     
  6. #12

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    You need to know that I always prefer red as hot because I am an electronics tech first and an HVAC second. Green would naturally be Bond, but it's already declared as, "fan". The usual is to not connect the low voltage wiring to Earth in any manner or fashion. Fact is, any GED that can schlep around behind a Journeyman for 4 years can try to pass the licensing test. I have found so many wiring fouls that we have a name for them. Named after the worst hack in the county, Kermit Thacker, they are called, "Kermit jobs". The cure is to disconnect every wire and do it over because it's quicker than trying to trace out all the mistakes. (I keep people's secrets until they are dead, so I must believe Kermit is dead, or I wouldn't speak of him.)

    You can twist 2 wires together and try to work them under a screw tip clamp, as in, "terminal block" pretending it is a stranded wire with big strands. More than two and you better be precise or you're going to cause an intermittent. Going under a screw head, the twisting usually won't work because there is not enough room. The all important fault is running one wire clockwise and the other counter-clockwise. Guaranteed to eject one wire when you try to tighten the screw. You can always pigtail to a group (low voltage or high) and place one wire under a screw. It's completely code and completely reliable. I prefer porcelain wire nuts because they catch a thread better than the blue or orange plastic crap you can buy, and they hold so well that you usually rip the ends off the wire before you can unscrew them. You twist stranded wire unto itself, but you do not twist solids going into a wire nut and you do not twist the twisted stranded wire with the solids going into a wire nut. They all go into the wire nut straight or it won't catch a thread.

    Did I miss anything?
     
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  7. MaxHeadRoom

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    There are control wiring colour codes per NFPA79 and NEC, one problem is that end device users often attach a short cable for hooking up to, these colours are often non-standard or can be different as laid out in The various publications.
    These come under exemptions Internal wiring on individual devices purchased completely wired.
    I generally use red or black for AC live, white neutral and green GND (or Grn with yellow stripe) of course.
    DC I try to keep Blue and where possible light blue for DC common.
    I tend to never use wire nuts unless absolutely necessary.
    The grounding of a secondary 120vac or 240vac conductor in order to re-establish a grounded neutral is optional under N.E.C., I tend to re-reference the GND.
    If you do not use a ground, then you should fuse both secondary conductors instead of just live.
    For keeping conductors small and less bulky I tend to use TR64 avoids filling up conduits or wire ways.
    Max.
     
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  8. jpanhalt

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    Jan 18, 2008
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    @#12

    Thank you for some quite useful information. I was not aware that you were not to twist solids going into a wire nut. I have seen that done many times and simply copied what I had seen. Also, I am going to look for those ceramic wire nuts. The types I have seen were plastic (hard or soft) with wire inserts.

    As for wire color, I also prefer red for hot too, and when I pull wires, that is what I use.

    John
     
  9. #12

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    You can twist the solids together, but it lowers the percentages that the wire nut will thread on the first try. If the remaining ends of the twist are too long, they won't go in the nut at all. If they are just right, it threads like magic. If the ends are cut off, the nut doesn't thread half the time. Leave the wires straight and your odds on a good catch, first try, exceed 80%. It also helps to leave one wire proud by a millimeter or so. That makes the raw end of the second solid act like the first thread of a mating screw. Now we're talking over 90% good thread on the first try.
     
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  10. jpanhalt

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    Sounds like I was doing it pretty much like you do, except for the twist. Leaving one wire a little longer definitely helps the start. For mains voltages, I also put a couple of wraps of 3M tape clockwise around the base of the nut and then the wires. Makes them a real pain to remove, but I feel better when I bend them to get into the box.

    John
     
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