The explosion protection type "intrinsically safe electrical circuit Ia" is based on the principle of limiting the maximum energy accumulated or released by an electrical circuit in emergency mode, or power dissipation to a level significantly below the minimum energy or ignition temperature of the surrounding explosive environment.
An intrinsically safe circuit is a circuit in which any spark or excess heat generated during normal operation is not capable of causing ignition of the surrounding environment.
When designing intrinsically safe circuits, it's important to consider the cable's reactance, which has a significant impact on energy storage in the circuit. Since low power consumption is one of the cable safety criteria, cables of relatively small diameters are typically used, which eliminates the need for reactance issues.