[RE-wrenches] garage door opener interference with enphase

[Exeltech]

Hello Mac,

Your conjecture about radiated interference as the cause is very likely correct.  RF is being generated by one or more inverters, and is swamping the garage door opener receiver .. rendering it "deaf" to the actual transmitter.

Corrective action(s) for RF interference requires special expertise - a skill I speculate is not common amongst the wrenches.  To make the diagnosis process more efficient, it also requires equipment I would speculate isn't found in wrench toolkits.  However, that said, troubleshooting can still be done.  It will just take more time.


My first comment .. toroids have a specific frequency range over which they can be used.  This is determine by the toroid's construction, and isn't always immediately evident from their appearance.  For example, toroids that "roll off" at 10 MHz won't be useful at 200 Mhz.  Garage door openers tend to operate in the high VHF to low UHF frequency range.  The toroids you use will have to be made for that spectrum.

Second, interference can be caused by "common mode" and/or "differential mode" signals traveling on the AC wires.  Again, the remedial actions are different from each other, depending on the path the interference is following.

Third, and most importantly, you need to put the toroids and other suppressive devices as close to the source of interference as possible.  This means at the inverters .. not in the panelboard.  When you install toroids at the panelboard, you've got all those tens of feet of connecting cable acting as an antenna.  It won't take much of an interfering signal to swamp out the signal from the garage door opener.

Here are some additional suggestions:

1. With all of the inverters operating, hold the garage door opener right next to the drive unit, and press the "open" button.  If it works, move away 5 or 10 feet and try again.  If the cause of non-opening is due to radiated interference from the Enphase array .. putting the opener immediately next to the receiver should override the interference from the inverters.  If the door does open with the remote immediately adjacent, then at some point you'll find a distance where it works erratically .. or not at all.

2. A possible step you can try .. it's my understanding the Enphase units can be disconnected from the utility one at a time.  If that's the case, disconnect *all* of them, close the AC disconnect, applying power to the power cable.  We're looking for the unlikely possibility of a tiny arc at this point.  Try the garage door remote at some distance.  If it works, then you've effectively exonerated the cable and its connections (for now).

3. Next, connect *one* inverter and try the door remote again.  If it opens .. then reconnect inverters back into the circuit one at a time.  You MAY find it's just one rogue inverter generating radio frequency interference ("RFI").  Continue to add inverters until the door doesn't open.  When you reach that point, disconnect the most recently connected inverter, and move down to the NEXT inverter in line, and repeat the open experiment again.  If the door opens .. continue adding inverters.  If it doesn't, it could be the cumulative effect of RFI from multiple inverters.


RFI troubleshooting without some sophisticated equipment (such as a "spectrum analyzer") is going to be a "divide and conquer" exercise for you.  It's going to be time consuming, but it can be done.


Due to the complexity of this situation .. we can discuss your situation in more detail on the phone if you wish.  I've posted this initial reply to the group because it's a situation others may encounter .. and the steps to find and attempt to remedy the source of interference are essentially the same.

I hope this is of some help to you.


Dan Lepinski


--------------------------------------------
On Sat, 1/18/14, Mac Lewis <maclewis1 at gmail.com> wrote:

Subject: [RE-wrenches] garage door opener interference with enphase
To: "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
Date: Saturday, January 18, 2014, 7:50 AM
 
Hello wrenches,

I have an issue that I am having a hard time figuring out.  I have a pending service ticket with enphase but I figured I'd throw it out to all your experience.
 
We have an enphase array mounted on a garage.  When the array is on (AC disconnect on) the garage door opener doesn't work at any acceptable range.  It works fine when the AC disconnect is off.  I have installed two toroids on each circuit.  I have moved these toroids around the circuits and it doesn't seem to help.  I have moved the garage door breaker to the opposite end of the service panel but it didn't seem to help
 
I am starting to wonder if the interference is radiative as opposed to traveling through the power lines.  Has anyone had any issues like this?  Were you able to find a solution?  I'm not sure how to deal with EM interference, any suggestions would be appreciated.
 
Thanks in advance
 
 -- 
 
 
Mac Lewis