Hi, I am pretty much a newbie to this sort of thing (I've done some wiring on breadboards way back in the day and am very good with software side of things but home wiring is not something I've done a terribly lot of). Basically my idea was to automate my HVAC with these requirements:
1. I'm a student (PhD), don't want to spend lots of $$$. (Also I currently don't have a soldering iron here so would like to avoid buying one if possible as it is extra $$$).
2. I want both AC and heat control via X10 (controller from my OpenWrt router which will soon have a 1-wire temp sensor as well and I can definitely handle the control logic side of all this).
3. I want either the router in control or the thermostat, not both (switched with X10).
4. I want X10 to never be able to switch AC & heat on at the same time, as this seems like a "bad thing" from what I've read (mainly this is b/c I keep reading about X10 reliability issues coming up so I want this hardwired).
I've investigated my HVAC system, have a basic 4-wire system and if I cross the right cables I get the right functions (cold turning on, heat turning on, well honestly I've actually only tested AC so far and it worked).
Here is what I am planning based on my constraints and my investigations. I don't know anything about the actual feasibility (I apologize for my poor man's diagrams):
So my questions are:
1. Is there something really big/obvious that will make this not work I am missing?
2. If it seems reasonable, how can I hook up the UM506 to the -/+ (the UM506 will just close contacts when
activated by X10) or do I need some kind of power supply? Can I use 24VAC as the power and if so would it be the
- or + pole and what would I hook the other one to? If not what do I need to use.
3. What 24V relay can I use for this? This ELK 12/24V heavy duty relay looks like a reasonable one to me:
http://www.safemart.com/index.asp?PageActi...WELAID=63026126
but I really don't know much about relays to be sure.
I realize there's a multi-SPDT X10 controllable relay I could use, but it seems like its $120-150 and I seem to
be able to do this whole set-up (3xUM506 modules plus 2 relays) for around $50-60 so it seems like it would fit better
with goal #1.
Thank you so much.
Misha
p.s. also my heat & AC are actually above my bathtub/shower (seems like an interesting place to put that kind of thing...). I could run a power strip to it along the ceiling (on the opposite site of the shower head) and I think it would be okay
but I am still worried about long term use with the shower and a power strip basically running within harm's reach of the water. Another option would be to hook it up through the AC inlet vent, which would mean I would have to cram both the powerstrip-wire and the filter there, and also that inlet is right in the middle of my living room and that would not really be an ideal setup aesthetically. Any good ideas for this sort of thing?
1. I'm a student (PhD), don't want to spend lots of $$$. (Also I currently don't have a soldering iron here so would like to avoid buying one if possible as it is extra $$$).
2. I want both AC and heat control via X10 (controller from my OpenWrt router which will soon have a 1-wire temp sensor as well and I can definitely handle the control logic side of all this).
3. I want either the router in control or the thermostat, not both (switched with X10).
4. I want X10 to never be able to switch AC & heat on at the same time, as this seems like a "bad thing" from what I've read (mainly this is b/c I keep reading about X10 reliability issues coming up so I want this hardwired).
I've investigated my HVAC system, have a basic 4-wire system and if I cross the right cables I get the right functions (cold turning on, heat turning on, well honestly I've actually only tested AC so far and it worked).
Here is what I am planning based on my constraints and my investigations. I don't know anything about the actual feasibility (I apologize for my poor man's diagrams):
Code:
24VAC 24VAC wire to
wall thermostat
| |
| |
| |
C NC
24V SPDT relay (wall thermostat vs X10 control)
- + NO
| | |
I want to switch these |
with a UM506 and I was |
thinking of using 24VAC |
as one of the contacts but \--
now I'm confused drawing UM506 (X10 heat/cool vs no
this diagram, can I just hook /-- X10 heat/cool)
up the UM506 with wires to the |
-/+ and have the relay work or |
do I need to also power these |
somehow since the UM506 will |
just close the contacts and not | HVAC AC wire HVAC Heat wire
apply any voltage. | | |
| | |
C NC NO
24V Relay (Heat or cool?)
- +
| |
Again I want UM506 in charge
here but don't know if I need external powerSo my questions are:
1. Is there something really big/obvious that will make this not work I am missing?
2. If it seems reasonable, how can I hook up the UM506 to the -/+ (the UM506 will just close contacts when
activated by X10) or do I need some kind of power supply? Can I use 24VAC as the power and if so would it be the
- or + pole and what would I hook the other one to? If not what do I need to use.
3. What 24V relay can I use for this? This ELK 12/24V heavy duty relay looks like a reasonable one to me:
http://www.safemart.com/index.asp?PageActi...WELAID=63026126
but I really don't know much about relays to be sure.
I realize there's a multi-SPDT X10 controllable relay I could use, but it seems like its $120-150 and I seem to
be able to do this whole set-up (3xUM506 modules plus 2 relays) for around $50-60 so it seems like it would fit better
with goal #1.
Thank you so much.
Misha
p.s. also my heat & AC are actually above my bathtub/shower (seems like an interesting place to put that kind of thing...). I could run a power strip to it along the ceiling (on the opposite site of the shower head) and I think it would be okay
but I am still worried about long term use with the shower and a power strip basically running within harm's reach of the water. Another option would be to hook it up through the AC inlet vent, which would mean I would have to cram both the powerstrip-wire and the filter there, and also that inlet is right in the middle of my living room and that would not really be an ideal setup aesthetically. Any good ideas for this sort of thing?
- and plus I really don't want to mess it up b/c I already have quite a few things set up on it such as security cam with automatic motion detection, VPN tricks for my work VPN, etc) but the relay board from Hobby Boards is SPST and I still favor a SPDT solution to make sure that heat & cool are never turned on together in hardware. 
