Priority on devices with small main fuse

Today I only have a 35A main fuse and need to prioritize which devices are allowed to run.

Among the largest consumers, I have a water heater connected to a relay with measurement capabilities, an Easee electric vehicle charger, and a Samsung washing machine. For instance, if all devices are running, I would prioritize based on:

  1. “Dumb” devices like ovens, etc., get first priority until they no longer draw power.
  2. Washing machine (SmartThings)
  3. Water heater
  4. Easee charger

For example, everything will be off except for the water heater and Easee charger. In that case, I want to adjust the maximum allowed draw on the Easee charger based on availability.

I’ve been considering a flow based on “current draw” with a script that prioritizes. Has anyone done something similar? Or is there an app for this that I might have missed?

That sounds like a job for the Piggy Bank app.

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Though, for the main fuse limitation there was recently discovered a bug related to if you had 3-phase or 1-phase: MaxDrain calculated wrongly for single phase main breaker · Issue #282 · frodeheg/no.sparegris · GitHub

This bug has been corrected on a development branch of PiggyBank, it’s not in the public version yet, but it will soon. Meanwhile this may or may not be an issue for you depending on if you use 1-phase or 3-phase. (A workaround may be to adjust the main-fuse to account for the error while waiting for the update)


Yes, I have single phase - was wondering why it allowed to draw in excess of 13kW .
Set the mainfuse to 20 and it works much better now.