For DIY’ers brave enough to install the sensors yourself - I just did with the new Gen5 plug-in model HEM and it worked first-time. DIY on electric service panels is not legal in many areas; consult your local codes. If you have any doubts or concerns, hire a licensed, qualified electrician to install the HEM for you.
- Before you begin, read all of the directions CAREFULLY! You’ll save yourself a lot of headaches if you do. Oh, did I mention? READ THE DIRECTIONS BEFORE YOU START!
- The L2 lead (the second one I installed) was a little sung going through the 1/2" (I.D.) knockout. I had to push the locking ring with a screwdriver to force it through. a 3/4" (I.D.) knockout clamp would have made it easier, but I had already opened the 1/2"-only hole in the panel box. If you must force anything, be careful not to damage the sensor leads. The retainer ring went through with just a little “encouragement.” The first wire went through easily. I’d suggest using the 3/4" clamp if you can. The directions don’t mention that.
- Instructions mention “K->L” direction indicators on the sensors. Several comments (and the directions!) say that it’s important to have them pointing the correct way. The K->L indicators are in very fine print on the top of the sensor. I had to use a bright light to see them. In the dark confines of the basement at the service panel I couldn’t see them at all, so I drew an arrow on each sensor with a marker. That helped.
- L1 and L2 are the large wires going into the main disconnect. (US setup) “Standard” colors are Black and Red for L1/L2, and White for Neutral, but many panels, mine included, just have two solid-black wires for L1/L2 and one black with a white stripe for Neutral. IF YOU’RE NOT CERTAIN, HIRE AN ELECTRICIAN AND DO NOT ATTEMPT TO DO-IT-YOURSELF! THE WIRES WHERE YOU INSTALL THE SENSORS ARE ALWAYS LIVE AND CANNOT BE TURNED OFF EXCEPT BY YOUR UTILITY SUPPLIER. The sensors just snap around the wires, but you must be very careful.
- Directions identify 'L1" and “L2” and the direction the arrows “point” is different for each side. (US setup). It indicates that “L1” should point INTO the main breaker, “L2” should point OUT OF the main breaker, and the HEM box should plug into an outlet on the 'L1" side. (That was the trickiest part for me, finding an outlet on the correct L1 side. I would guess that one cause for negative readings might be plugging the HEM into the L2 side, in effect making the arrows point in the wrong direction.)
- Find the right driver! Unfortunately most of the “AEON LABS” drivers are at the top of my SmartThings hub list, so I chose the “Aeon Home Energy Monitor.” That worked, but only gave me a kWH reading. I looked again, and found the “Aeon HEM Gen5” driver was all the way at the bottom of the list. The list is in alphabetical order - but only for the “factory” drivers. The ones you import yourself are at the bottom of your list. SCROLL DOWN!
- Aeontec’s directions to import the Gen5 driver into your SmartThings Hub from github are excellent, and you’ll succeed on your first try - IF YOU READ AND FOLLOW ALL DIRECTIONS!
My A/C is on today, and I’m watching the energy usage. I put in the kWH price in our area and now I think I want to cry.
Good luck, be safe, and hire an electrician unless you’re absolutely certain you can DIY safely and your local codes allow you to DIY.