Nick
I think you mean arc resistant gear, not "arc rated".
If there are no sensors installed, it's possible someone else will discover it "the hard way".
A common misconception about the arc-resistant switchgear is the purpose of its design.
Arc-resistant switchgear is designed to contain the arc inside the switchgear and exhaust the gases that result from the arc through a plenum to keep the workers around the switchgear safe. However, all of this is meant to happen when the switchgear is closed. When the switchgear is open, it loses its benefit as arc-resistant! This means when someone is performing maintenance, thermal scanning, or even if the switchgear panel is missing a bolt, danger is still a factor.
Although having arc-resistant switchgear increases safety in some instances, be prepared for incidents that happen when someone is working with live equipment. It’s best to identify the hot spots by performing a study, reduce the incident energy levels at those spots using arc flash mitigation solutions and/or proper coordination, and keep maintaining the equipment periodically in order not to miss that bolt somewhere!
Converting energy to motion for more than half a century