Class 3 Power Limited Circuit Cable

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.

Class 3 power limited circuit cable. The limited power and voltage of these circuits is what makes them a separate and specialized wiring method. May be installed in raceways conduit cable trays and. 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. Equipment listed as a class 2 or class 3 power source amplifier for audio program signals.

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. Tray cable is a multi conductor control signal or power cable rated for 600 volts. This article will help distinguish the differences between these circuits. Listed information technology equipment.

725 41 the power source for a class 2 or a class 3 circuit must be one of the following. Remember that the class 2 or 3 circuit begins at the power supply. Mini split tray cable 600 volt. 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.

But remember most class 2 or 3 circuits usually are wired using listed cable types specified by the nec. Option 2 listed class 2 power supply is easier to achieve than option 4 limited power circuit acc. For example heating system thermostats are commonly class 2 systems and the majority of small bell buzzer and annunciator systems are class 2 circuits. 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.

Also class 1 remote control circuits are limited up to 600 volts with no other. A listed class 2 or class 3 power supply. The following graph shows a comparison of nec class 2 i max limits with ul 60950 limited power circuit requirements. Mini split wire is a class 3 power limited circuit cable used with hvac mini split systems.

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 supplying class 2 or 3 circuits must be marked to indicate each circuit that is a class 2 or 3 circuit 725 42. That means conductors and equipment on the supply side of the class 2 or 3 power source must be installed in accordance with chapters 1 through 4 725 51. The power supply connected to a class 1 2 or 3 circuit for the most part determines the class of that circuit.

The minimum size circuit is 18 awg when a class 2 or 3 circuit is reclassified and used as a class 1 circuit.