In environments with substantial IT equipment, managing inrush current is essential to prevent circuit breakers from tripping. This article explains how to use Tasmota, an open-source firmware for ESP8266 and ESP8285-based devices, to handle inrush current effectively. The approach involves configuring Tasmota rules to stagger the power-on sequence of devices.

Understanding Inrush Current

Inrush current refers to the initial surge of current required when electrical devices are first powered on. This surge can be significantly higher than the device’s operating current. When multiple devices are connected to a single outlet, the combined inrush current can trip circuit breakers or blow fuses.

Configuring Tasmota to Manage Inrush Current

Tasmota firmware allows for the customization of device behavior through rules. By setting up a rule to delay the power-on sequence, the inrush current can be managed more effectively.

Steps to Configure Tasmota

1. Set Default Power State: Ensure the device remains off when power is restored. This prevents an immediate surge when the power comes back on.

   PowerOnState 0
   

2. Create a Power-On Delay Rule: Define a rule that delays the power-on sequence when the device boots up. This example sets a 10-second delay.

   rule1 on system#boot do ruletimer1 10 endon on Rules#Timer=1 do power on endon
   rule 1 1
   

Example Configuration

PowerOnState 0
rule1 on system#boot do ruletimer1 10 endon on Rules#Timer=1 do power on endon
rule 1 1

This configuration ensures the device remains off initially and powers on after a 10-second delay, reducing the inrush current.

Additional Considerations

1. Load Balancing: Distribute the load across multiple outlets or circuits to prevent overloading a single outlet.

2. Using Surge Protectors: Consider surge protectors with built-in delay mechanisms designed to manage inrush currents.

3. Monitoring Power Consumption: Regularly monitor the power consumption to ensure it stays within safe limits.

Conclusion

Managing inrush current is crucial in environments with significant IT equipment to prevent circuit breakers from tripping. Tasmota firmware offers a flexible solution by allowing the configuration of power-on delays. This approach helps to stagger the power-on sequence, effectively reducing the inrush current. For environments with multiple devices, implementing a staggered power-on sequence and distributing the load can further enhance stability.

For more detailed information on Tasmota, refer to the Tasmota documentation.