I use a generator interlock, so when the grid power comes back the only thing that changes in my panel is voltage on the wires above the main breaker, as I am powering the rest of the panel through an interlock’d breaker.
I hate the idea, even fused, of trying to attach an indicator light to hot service entry leads (which I’ve seen recommended).
Are there esphome/esp32 compatible sensors that are proximity based, so I could mount it (for example) on the insulated area of those entry wires and sense when they have voltage? I have a suitable external box already for the ESPHOME outside the panel (I use it for iotawatt).
Note since I won’t draw power until I throw the interlock, I can’t use the current transformers I already have on it, as there’s only voltage not current.
Could you not just use a non contact ‘wand’ and hikack the output from that to make a pin go hi on an ESP? They are three volt and so you could even power the wand from whatever you’re using to power the
ESP.
While looking further for options I stumbled across a product called Powerback (THP108) that serves this purpose though it is an audible alarm not something HA integrated.
I’ve seen a bit of mixed signals on it working, but it’s already made to go in a panel in a knockout, it certainly may be an easier choice.
A contact sensor is easier, but my problem is the mains power to the breaker is not switched (you have to pull the meter to power it off). Anything that has to connect electrically to that wire means working on it hot - solder, screw, wire wrap, whatever. I’m fairly comfortable working around hot wires but that seems just too risky.
I’m note even sure how I feel about wrapping the Powerback wire around the insulation. I need to go open up the panel and see how much working space I have.
But the death-stick idea above (non-contact voltage pens) is interesting for another reason. I don’t really need an alarm to wake me up, I just want something I can check easily. I need to go see if I can get a reading on the service entry cable itself. Maybe I’ll just use that. It’s not as elegant as a HA integrated system, but it’s rarely needed.
I’ll look further at some of the circuits given above. Maybe I’ll build something also.
Your case should be quite easy since you don’t have interferences from other wiring when power is off. It’s much harder to detect (NCV) some specific wire surrounded by hot wires.
Anyway, I would be surprised if your code doesn’t allow certified indicator led on the supply side. Din rail indicators cost just few bucks. That you can detect with (few bucks) esphome board and phototransistor.
Well, depends on how close “hot” is. I do have a lot of exposed service entry wire (insulated) at the top, would be easy to wrap stuff around. I’m pleasantly surprised there is almost no exposed conductor; this is a new panel and they have all sorts of plastic shields over the SE conductor attachment points.
But when I’m on battery/generator there are a number of hot wires crossing over (literally touching) the service entry cables. So… just depends on how close is close.
I have no idea of the code for direct wired indicator LED’s. I can’t recall ever seeing one on a panel. Frankly a “hot” LED on the panel inputs would seem like a really cheap safety add-on from Eaton (etc), but never seen one on residential stuff.
So this isn’t really what you asked for OP, but I am planning an interlock switch and am going to have the same problem to solve. I have a smart meter so recently built an ESPHome device with an SX1276 transceiver that listens for the broadcasts from my smart meter. It’s the same signal the PoCo uses to read my meter. I use the presence/absence of that signal to toggle a binary_sensor for grid status. As in if it doesn’t hear a broadcast for 2 mins (adjustable) it toggles the sensor off and when it hears the broadcast again it toggles it back on. Side benefit I also get my consumption data into HA from the broadcast.
Figured I’d mention another non-contact way to approach this if your meter also broadcasts a signal.
Now that’s a really cool idea. I stared at my (smart) meter the other day, wondering if I could somehow recognize that the display was changing (and sort it from shadows and such), but that seems much more straightforward, and I assume I can put the receiver indoors.
I assume I can’t tell if it broadcasts regularly and on a suitable frequency ahead of time?
Did you post your working setup anywhere and/or care to share the yaml and I’ll hunt for wiring.
Give me a little bit to cleanup and sanitize what I have and I’ll post my YAML. Current state is a POC and I have some extra stuff in there… I have a buddy that has a similar need but doesn’t use HA or any other automation system. He has an iPhone so I used a Homekit component to expose the grid status as a switch so he’d be able to see status easily in the Home app. (I know exposing it as a switch is weird since you can’t actually control it, but I wanted it to show up right on the main screen of his Home app, and this works fine)
I don’t know how to tell you how to determine if or how your meter broadcasts – you’ll probably just need to look it up. I can tell you mine broadcasts many times per minute. Mine is on 912.6Mhz. I had previously played with a Software Defined Radio (SDR) so already knew my meter was broadcasting and knew my meter ID.
Mine is using OOK modulation and and I think what you’re describing is FSK? Everything I found when researching this says power meters use OOK for ERT-SCM. What I will say is that the config I’m pasting below will log ANY ERT-SCM messages it sees. I also have it add all of the IDs it sees to a text sensor. I did this to make it easier for someone to try to find their meter. I already knew mine so didn’t need that functionality but figured why not. If you start receiving signals you should be able to figure out which is yours by looking at the ID and KwH number and then looking at your meter to see what matches - that’s how I originally found mine.
Here’s my config:
** Disclaimer - I’m not a developer and my code probably shows that.
esphome:
name: ##REDACTED##
on_boot:
priority: -10 # Runs after everything is initialized
then:
- binary_sensor.template.publish:
id: grid_power_status
state: OFF
- script.execute: watchdog_timer
esp32:
board: esp32dev
framework:
type: esp-idf
# Enable logging
logger:
level: INFO
api:
ota:
platform: esphome
wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
web_server:
external_components:
- source: github://juanboro/esphome-rtl_433-decoder
components: [ rtl_433 ]
globals:
- id: last_reading_timestamp
type: int
initial_value: '0'
spi:
clk_pin: GPIO18
mosi_pin: GPIO23
miso_pin: GPIO19
sx127x:
id: sx1276_radio
cs_pin: GPIO25
rst_pin: GPIO22
frequency: 912.6MHz
modulation: OOK
bitrate: 32768
bandwidth: 250_0kHz
packet_mode: false
rx_start: true
bitsync: false
rx_floor: -90.0 # Ignores weak noise that might be jamming the decoder
remote_receiver:
id: rf_receiver
pin:
number: GPIO2
mode: INPUT_PULLUP
dump: [] # Turn off raw; we know the signal is perfect now
buffer_size: 25000
idle: 25ms
filter: 20us
rmt_symbols: 512
rtl_433:
id: my_decoder
receiver_id: rf_receiver
on_json_message:
then:
- lambda: |-
std::string output;
serializeJson(x, output);
ESP_LOGW("METER_HIT", "JSON: %s", output.c_str());
if (x.containsKey("id") && x.containsKey("model")) {
std::string model = x["model"].as<std::string>();
// Only proceed if it's an ERT-SCM (Power Meter) message
if (model == "ERT-SCM") {
std::string new_id = x["id"].as<std::string>();
std::string current_list = id(detected_ids_list).state;
// Deduplicate and check character limits
if (current_list.find(new_id) == std::string::npos && current_list.length() + new_id.length() < 250) {
if (current_list.empty() || current_list == "Unknown" || current_list == "Never heard") {
id(detected_ids_list).publish_state(new_id);
} else {
id(detected_ids_list).publish_state(current_list + ", " + new_id);
}
}
}
}
// Convert the text input value to a long integer for comparison
long target_id = atol(id(target_meter_id).state.c_str());
if (x["id"].is<int>() && x["id"] == target_id) {
// Use the new ArduinoJson 7 syntax to check for the keys
if (x["consumption_data"].is<float>()) {
id(meter_reading).publish_state(x["consumption_data"]);
} else if (x["consumption"].is<float>()) {
id(meter_reading).publish_state(x["consumption"]);
}
id(last_reading_timestamp) = millis() / 1000;
id(grid_power_status).publish_state(true);
id(meter_last_seen_text).update();
id(watchdog_timer).stop();
id(watchdog_timer).execute();
}
sensor:
- platform: template
name: "Power Meter Reading"
id: meter_reading
unit_of_measurement: "kWh"
device_class: energy
state_class: total_increasing
binary_sensor:
- platform: template
name: "Grid Power Status"
id: grid_power_status
device_class: connectivity
text_sensor:
- platform: template
name: "Meter Last Heard"
id: meter_last_seen_text
icon: "mdi:clock-outline"
update_interval: 30s
lambda: |-
if (id(last_reading_timestamp) == 0) {
return {"Never heard"};
}
uint32_t now_s = millis() / 1000;
uint32_t diff = now_s - id(last_reading_timestamp);
if (diff < 60) return {to_string(diff) + "s ago"};
if (diff < 3600) return {to_string(diff / 60) + "m ago"};
return {to_string(diff / 3600) + "h ago"};
- platform: template
name: "Detected Meter IDs List"
id: detected_ids_list
icon: "mdi:format-list-numbered"
text:
- platform: template
name: "Target Meter ID"
id: target_meter_id
optimistic: true
min_length: 1
max_length: 12
initial_value: "##REDACTED##"
restore_value: true
mode: text
entity_category: config
on_value:
then:
- script.execute: watchdog_timer
number:
- platform: template
name: "Watchdog Delay Minutes"
id: watchdog_delay_mins
optimistic: true
min_value: 1
max_value: 30
step: 1
initial_value: 5
restore_value: true
unit_of_measurement: "min"
mode: slider
entity_category: config
on_value:
then:
- script.execute: watchdog_timer
script:
- id: watchdog_timer
mode: restart # Restarting resets the delay timer
then:
- delay: !lambda |-
// Convert minutes from the number component to milliseconds
return id(watchdog_delay_mins).state * 60 * 1000;
- lambda: |-
ESP_LOGW("WATCHDOG", "No signal for %.0f minutes! Grid down.", id(watchdog_delay_mins).state);
id(grid_power_status).publish_state(false);
button:
- platform: restart
name: "Restart"
entity_category: config
- platform: factory_reset
name: "Factory Reset"
id: Reset
entity_category: config
- platform: safe_mode
name: "Safe Mode"
internal: false
entity_category: config
No problem. An SDR is a fun little device to play with anyways. You can find neighbor’s weather stations, motion sensors, temp sensors, curtain controllers, etc. You can also do stuff like receive radar maps from weather satellites and other nerdy things.
I just happened to have built the device I shared my code for about a week ago so it’s all very fresh. It’s also a little bit of a work in progress but is working well for me so far. And I forgot to answer one of your questions: Yes, my device is inside my house. It had to me much closer to my meter than I anticipated but right now I’m just using a simple piece of wire for the antenna (but the correct length).
