In case you have multiple loads which will can consume more than 120A @ 12V / 100A @ 24V, you can also use the second relay. It is even possible to use multiple SmartRelays!

Example

You have two inverters of 100A, one used for cooking electric and one used for the oven.

Connect input 1 of the SmartRelay to input 2 of the SmartRelay. When relay 1 turns on, relay 2 will also turn on. Switch the power of inverter 1 with the first relay on the SmartRelay and inverter 2 with the second relay on the SmartRelay block.