Spare capacity in Industrial Control Panels

Last edit: 11/05/2024

The Doubt: In an Industrial Control Panel, is it required to leave a certain Spare capacity for “future” development?

Considerations: The reference standard for Electrical Equipment of machinery is IEC 60204-1 (In Europe that becomes EN 60204-1). That standard does not require any spare capacity inside control panels

Another standard sometimes used is IEC 61439-1 and IEC 61439-2. Also inside those 2 standards there is no request for spare capacity to be present inside the panel.

So, where is this requirement coming from? The requirement comes from some National Electrical Codes like the Italian CEI 64/8 that requires, for Electrical Panels installed in houses, “To allow subsequent expansions, the panels must be sized for 30% more than the modules installed, with a minimum of two modules, or a larger space if required by constraints linked to the maximum power dissipated by the panel [CEI 64/8 §37.4.1]”.

We can also have a look at the North American Standards, only to realise that there is not any mentioning of spare capacity language in any of them: nothing in UL 508A; nothing in NFPA 79 nor C22.2 N° 286, nor C22.2 N° 301.


When designing Industrial Control Panels, there is no normative requirement to leave a certain space capacity for future mounting of components. That is also in line with the fact that, normally, an Industrial control Panel is not subject to “growth”.

Safety in Collaborative Robotics
There is no “Collaborative Robot”. That is one of the first statements you hear from people working in Collaborative Robotics. The reason is because...