Why use a class 2 power supply?

Using a Class 2 power supply in a control system can be a factor for reducing the cost and improving the flexibility of the control system. This occurs when the voltage level of the control circuits is changed from AC voltage to DC voltage and NEC article 725 can be applied. This can result in a large cost savings benefit. Class 2 circuits have reduced requirements regarding insulation, wire size, derating factors, overcurrent protection, wiring methods and installation materials. This means the wiring can be exposed and does not need to be routed through conduit or other raceways. This makes an NEC Class 2 power supply useful for wiring in circuits, which have fewer restrictions than if the supply did not meet the NEC Class 2 rating.