Class 3 Power Limited Circuit Cable

But remember most class 2 or 3 circuits usually are wired using listed cable types specified by the nec.

Class 3 power limited circuit cable. Also can be used in security and audio applications. Equipment supplying class 2 or 3 circuits must be marked to indicate each circuit that is a class 2 or 3 circuit 725 42. This article will help distinguish the differences between these circuits. Tray cable is a multi conductor control signal or power cable rated for 600 volts.

A class 1 circuit is the portion of the wiring system between the load side of the overcurrent protection device ocpd or the power limited supply and the connected load. Remember that the class 2 or 3 circuit begins at the power supply. The following graph shows a comparison of nec class 2 i max limits with ul 60950 limited power circuit requirements. For example heating system thermostats are commonly class 2 systems and the majority of small bell buzzer and annunciator systems are class 2 circuits.

These circuits are designated class 1 2 and 3 not to be confused with the class i ii and iii hazardous locations an entirely different matter. Equipment listed as a class 2 or class 3 power source amplifier for audio program signals. Nec class 2 i max limits versus ul60950 limited power circuits 0v 5v 10v 15v 20v 25v 30v 35v 40v 45v 50v 55v 60v 65v. Mini split tray cable 600 volt.

The nec in article 725 makes a sharp distinction between wiring for ordinary power and light circuits and specialized circuits where the power and or voltage is limited. Also class 1 remote control circuits are limited up to 600 volts with no other. A listed class 2 or class 3 transformer. The power supply connected to a class 1 2 or 3 circuit for the most part determines the class of that circuit.

725 41 the power source for a class 2 or a class 3 circuit must be one of the following. The maximum circuit voltage is 30vac and 60vdc for a class 2 power source limited by overcurrent protection and 150vac or vdc for a class 3 power source limited by overcurrent protection. A listed class 2 or class 3 power supply. For example class 1 power limited circuits are supplied by a power supply with an output that does not exceed 30 volts and 1 000 volt amps.

The minimum size circuit is 18 awg when a class 2 or 3 circuit is reclassified and used as a class 1 circuit. Listed information technology equipment. Mini split wire is a class 3 power limited circuit cable used with hvac mini split systems. Ul 13 standard for safety for power limited circuit cables which lists 30 awg as the smallest for class 2 and 24 awg for class 3.

The limited power and voltage of these circuits is what makes them a separate and specialized wiring method.