I have been toying with the idea of controlling household load during peak hours. Something like ensuring that when the AC kicks on, the water heater is turned off. Additionally turning off clothes dryers, washing machines, dish washers during peak hours.
I would want to control these near the panel - preferably right after the breaker. For many of these I would need high amp relays to handle the power draw. Also, would I need to use two levels of relays - one low voltage connected directly to Raspberry Pi and a second high voltage relay?
As a first step, does anyone know of reasonably priced relays that can handle 120v 30, 40, 50 amp?
Your easiest way to control the A/C is a connected thermostat. There are numerous options ready for simple installation.
Not sure I would want to disable the washer and dryer. Assuming they are started manually, stopping mid cycle is not normally advised. You might have some indicating light near them to warn folks to now start them.
There are 30 relays that are reasonable but 40 and 50 get very specialized. You would have to install a metal box near the breakers, run the wires to and from the "new" box with the relays. This is very similar to a generator transfer panel.
A/C replacement parts like this might work however you will need a 2nd relay to power the large relay from a Pi.
This is not a project for someone who has no experience with house wiring. It's dangerous and there are a lot of rules that aren't intuitive.
That was my first thought as well. All this high current stuff is expensive and has some specific electrical code issues like noted.
The thermostat is fairly easy, you can either interrupt the "Y" wire (which is what my generator panel does) or use a smart thermostat and some Hubitat rules.
The simplest thing to do is to change your habits. Long term that is what works. Set the dishwasher to delay start 2 hours after dinner. Set the thermostat higher when away. Don't wash clothes until after you get home from work.
The other thing to consider is what happens when someone NEEDS some laundry done, and the washer dryer won't start until 8 PM or whatever. Or you are having a party and you cannot start the dishwasher or turn down the A/C. This is where better habits are more effective than an automation.
I completely agree that habits are the critical bit. With Hubitat, the circuit can always be re-energized, but that takes extra steps, which begins to build better habits.
However, if all I do is fuss at my kids and hubby, then nothing changes. If they can't run the dishwasher just by turning it on, then they have a pain point. Go find the tablet, log into the dashboard, activate the dishwasher, etc. Over time, this should change habits.
I use Hubitat for energy saving also, here in Quebec, we have the possibility to hop on a program that makes you save a lot of money when we have the coldest days of the year (so most of the time it's regular price) so when I get an alert saying that tomorrow will be a peak day, I turn on a virtual switch that indicates to Hubitat to turn off high energy appliances like water heater, garage heating, freezer, spa, etc. and set baseboard thermostats to 15C. We have a wood stove that with crank up when we get home from work. The car is also programmed, not via Hubitat, to only charge between 10pm and 6am between december 1st to March 30th but has a bypass when needed.
For the rest, we just mind ourselves to not use the stove, dryer, etc and this works great. Saved about 140$ last year alone.
It will cost you a few bucks to just turn things off at the breaker. Not gonna go into this debate about your family but Don't just cut off power at the breaker panel.
The old appliances create surges when switch on from the panel and will damage your smart devices in the long run.
The new appliances won't last as long when giving them heart attacks.
