Waketech Posted October 11, 2016 Share Posted October 11, 2016 All, So I finally installed an air exchanger in my garage (due to high humidty problems) and I am looking to automate. My initial though was to use the relays to control different functions however the controller does not seem to operate the device (open/close connections like a relay). I used an ohm meter to test the 4 connection pins at the controller and no matter what position I select there is not short/open based on switch position. I have tried calling the manufacture but as you can imagine they were no help. The main issue is that the device needs manual intervention (on / low / high / re-cir, I could just power the unit on/off with a controlled plug however I think this would wreck the device >. Any thoughts ? Link to comment
mwester Posted October 11, 2016 Share Posted October 11, 2016 Er... you really do need to post manufacturer and model numbers (for both exchanger and the controller) for anyone to be able to help you out... Link to comment
Waketech Posted October 11, 2016 Author Share Posted October 11, 2016 Er... you really do need to post manufacturer and model numbers (for both exchanger and the controller) for anyone to be able to help you out... Sure, Venmar EA 1500 http://www.venmar.ca/37-air-exchangers-ea-1500.html , there is reference to the controller in the manual Link to comment
mwester Posted October 11, 2016 Share Posted October 11, 2016 Looks like the control with that one (C34) is a computer-based control -- so the wires are probably power and ground for the control unit, data-in, and data-out. There's no simple switch or relay that'll control that thing. Link to comment
Waketech Posted October 11, 2016 Author Share Posted October 11, 2016 Looks like the control with that one (C34) is a computer-based control -- so the wires are probably power and ground for the control unit, data-in, and data-out. There's no simple switch or relay that'll control that thing. That's what I was afraid of, so my options are.. 1) power the device on/off as needed (I assume this will wreck it over time ?) 2) Try to find something on the main board (I know there are physical relay's mounted on there it's just to find out what they do) ? Link to comment
stusviews Posted October 11, 2016 Share Posted October 11, 2016 The colors correspond to standard HVAC colors. Measure the voltage between red and black. If it's about 24VAC, then yellow is the standard for cooling and green is for the fan. What did you find for the voltage? Link to comment
Waketech Posted October 11, 2016 Author Share Posted October 11, 2016 The colors correspond to standard HVAC colors. Measure the voltage between red and black. If it's about 24VAC, then yellow is the standard for cooling and green is for the fan. What did you find for the voltage? Will check and advise later tonight Link to comment
Waketech Posted October 11, 2016 Author Share Posted October 11, 2016 Will check and advise later tonight Ok Red/Black was 5 volts Link to comment
Waketech Posted October 11, 2016 Author Share Posted October 11, 2016 Ok Red/Black was 5 volts Switch Off Black/Green = 4.00 Black/Red = 5.00 Black/Yellow = 0.00 Green/Red = 0.93 Green/Yellow = 4.00 Red / Yellow = 5.00 Switch ON Black/Green = 3.40 Black/Red = 4.92 Black/Yellow = 4.60 Green/Red = 1.563 Green/Yellow = 1.182 Red / Yellow = 0.382 Link to comment
stusviews Posted October 11, 2016 Share Posted October 11, 2016 Doesn't the switch have four positions, O(ff), Minimum, Maximum and Recirculation, not just On and Off? Link to comment
DennisC Posted October 11, 2016 Share Posted October 11, 2016 I would suggest running a different test. Disconnect the control from the unit. Install a temporary pigtail into the controls wiring terminal leaving the other end of the cable loose but not shorted to anything. Run thru the various control settings using an ohmmeter on the wiring. If you can find the right combination of switch contact closures, you might be able to control it via open/closed contacts. If that is the case, it would open up some possibilities. I want to stress here, to make sure the control is disconnected from the unit. You don't want to damage the unit. This shouldn't impact the control, as you are not connecting a voltage source to the control. Link to comment
Waketech Posted October 11, 2016 Author Share Posted October 11, 2016 Doesn't the switch have four positions, O(ff), Minimum, Maximum and Recirculation, not just On and Off? Yes it does, I only did one switch position, can do more if needed Link to comment
Waketech Posted October 12, 2016 Author Share Posted October 12, 2016 I would suggest running a different test. Disconnect the control from the unit. Install a temporary pigtail into the controls wiring terminal leaving the other end of the cable loose but not shorted to anything. Run thru the various control settings using an ohmmeter on the wiring. If you can find the right combination of switch contact closures, you might be able to control it via open/closed contacts. If that is the case, it would open up some possibilities. I want to stress here, to make sure the control is disconnected from the unit. You don't want to damage the unit. This shouldn't impact the control, as you are not connecting a voltage source to the control. So essentially I am bridge the gap between controller and unit with the ohm meter and at any point in time there will only be two connections (one on either side of the ohmmeter) Link to comment
DennisC Posted October 12, 2016 Share Posted October 12, 2016 So essentially I am bridge the gap between controller and unit with the ohm meter and at any point in time there will only be two connections (one on either side of the ohmmeter) What you want to try is to determine which wires are closing for each switch position. You will need to move the ohmmeter leads thru all possible combinations to properly identify all of the contact positions. Link to comment
Waketech Posted October 12, 2016 Author Share Posted October 12, 2016 What you want to try is to determine which wires are closing for each switch position. You will need to move the ohmmeter leads thru all possible combinations to properly identify all of the contact positions. so the other ones (not under test) will be connected as normal ?, I am just trying to understand your caution note fully Link to comment
DennisC Posted October 12, 2016 Share Posted October 12, 2016 so the other ones (not under test) will be connected as normal ?, I am just trying to understand your caution note fully No! Completely disconnect the controller from the unit. Imagine taking a wall switch in your hand and connecting a ohmmeter to the terminals and turning the switch on and off. The only difference is you will have a four position switch and you must test each wire combination at each switch position. I hope this example makes it clear for you. Link to comment
Waketech Posted October 12, 2016 Author Share Posted October 12, 2016 No! Completely disconnect the controller from the unit. Imagine taking a wall switch in your hand and connecting a ohmmeter to the terminals and turning the switch on and off. The only difference is you will have a four position switch and you must test each wire combination at each switch position. I hope this example makes it clear for you. Ok, got you. I did that last night and there is no open/close like a normal relay Link to comment
DennisC Posted October 12, 2016 Share Posted October 12, 2016 Ok, got you. I did that last night and there is no open/close like a normal relay If you are sure there is no open/close combinations then I am out of suggestions. Link to comment
stusviews Posted October 12, 2016 Share Posted October 12, 2016 Yes it does, I only did one switch position, can do more if needed Leave the black and red connected. Disconnect the green wire. Flip the switch through Minimum, Maximum and Recirculate. What are the results? Reconnect the green wire, disconnect the yellow wire and run the same tests. Link to comment
Waketech Posted October 12, 2016 Author Share Posted October 12, 2016 Leave the black and red connected. Disconnect the green wire. Flip the switch through Minimum, Maximum and Recirculate. What are the results? Reconnect the green wire, disconnect the yellow wire and run the same tests. Stu, what am I measuring to/from ? Link to comment
stusviews Posted October 12, 2016 Share Posted October 12, 2016 Don't measure anything. What is the result at each position with each wire disconnected, that is, what functions, what doesn't, which indicators light, don't light at each posiition? Link to comment
Waketech Posted October 12, 2016 Author Share Posted October 12, 2016 Don't measure anything. What is the result at each position with each wire disconnected, that is, what functions, what doesn't, which indicators light, don't light at each posiition? Ok so here are the results.... Both green and yellow disconnected Result = Nothing happens to any function Green connected, yellow disconnected Result = Fan goes through it's three stages, no lights are illuminated Yellow connected, green disconnected Result = No fan function, two lights blink (not corresponding to switch position) Link to comment
stusviews Posted October 12, 2016 Share Posted October 12, 2016 There may be only the original solution you proposed, that is, controlling power to the unit. If there is one setting that you would leave it on when you want it on, for example, only one of minimum, maximum or recirculate, then set it to that mode and unplug it. Wait a minute or two and plug it back in. If the air handler returns to that setting, then you should be OK using an ApplianceLinc. That will not damage the unit. Consider that that's the same as setting the unit to a mode and then, after a while, turning it off, later returning to that same setting. Link to comment
Waketech Posted October 13, 2016 Author Share Posted October 13, 2016 There may be only the original solution you proposed, that is, controlling power to the unit. If there is one setting that you would leave it on when you want it on, for example, only one of minimum, maximum or recirculate, then set it to that mode and unplug it. Wait a minute or two and plug it back in. If the air handler returns to that setting, then you should be OK using an ApplianceLinc. That will not damage the unit. Consider that that's the same as setting the unit to a mode and then, after a while, turning it off, later returning to that same setting. Thank you for the help in working on this. I have determined that the unit will return to operation based upon the last switch position. My intent will be to turn on when needed and run for x amount of time to avoid cycling of the device. My worry is that too much power on/power off my damage the device or am I over worrying ? Link to comment
larryllix Posted October 13, 2016 Share Posted October 13, 2016 Thank you for the help in working on this. I have determined that the unit will return to operation based upon the last switch position. My intent will be to turn on when needed and run for x amount of time to avoid cycling of the device. My worry is that too much power on/power off my damage the device or am I over worrying ? I have a Venmar HRV that I cycle every 40 minutes for the last 8 years but I switch it from the input sensing and the timer input sensing. Link to comment
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