![]() When the ballast is the sink of a Class 2 limited power circuit, the circuit shall be identified as “Class 2 Circuit” to indicate that the ballast is intended for connection to a Class 2 circuit.Īs we have completed the wiring requirements of Class 1 circuits, let us look into the factors that matter in Class 2 wiring!Ĭlass 2 circuit conductors in enclosures, compartments, outlet boxes, device boxes, or similar fittings shall be permitted to be installed with electric light, power, Class1,…circuits where they are introduced solely to connect the equipment connected to Class 2 circuits and where (1) or (2) applies: The 0-10V driver and ballast are labeled “Class 2” because the ballast is a sink of power not a source. (1) Class 1 and power supply circuits shall be allowed to occupy the same cable, enclosure, or raceway only when associated functionally. (B) Class 1 circuits may be established using power supply wires that meet the following requirements: (A) Class 1 circuits may share the same cable, cable tray, enclosure, or raceway, regardless of whether they are alternating or direct current.Īs long as all conductors are insulated to the maximum voltage of any conductors in the cable, cable tray, enclosure, or raceway. ![]() Now let us see the Class 1 wiring methods recommended in NEC Requirement 725.48Ĭlass 1 circuits are allowed to install with other circuits as specified in 725.48 (A) and (B): Fiber optic cable - used for long-distance.The Common types of cables used in low-voltage wiring include: Is inherently flexible as most codes do not require it to be installed in conduit. It is not very flexible, imposing limited control options and rigid zoning based on lighting circuiting Provides a pathway for communication of analog or digital signals, such as incoming sensor input data-e.g., light levels, occupancy conditions-and outgoing commands. Provides both power to lighting fixtures and also a means of grouping them by circuit/switch-leg within “control zones” Class I vs Class II wiring Class I- Line Voltage Wiring NEC is the benchmark for safe electrical design, installation, and inspection to protect people and property from electrical hazards.Ĭlass 1 wiring refers to line voltage conductors that transmit current at a value of up to 600 volts. It requires wires with insulation rating for the voltage carried (usual wiring has 600V rated insulation), or conduit, or a protective cable assembly. Class 2 wiring is defined as low voltage conductors with low current and do not have enough voltage or current to pose a hazard and have less stringent installation standards in terms of wiring protection. The best thing about Class 2 wiring is that it can be installed free within the wall or ceiling without protection of conduit or a cable assembly, otherwise line voltage rated insulation. And, when considering the 0-10V dimming, NEC classifies the wire systems as Class 1 and Class II. You might be aware that the classification of various wiring systems is detailed in Article 725 of National Electrical Code (NEC). ![]() So now let us discuss about 0-10V wiring in detail. If the wiring is not proper, it will lead to severe problems. Since wiring is an important element in any lighting network, in this blog we will discuss about 0-10V wiring. Like a human brain, control wiring communicates, commands and passes information between control devices in a lighting network. Typical NM Ground Wire Connections Diagram is shown below.Let us continue to learn about 0-10V from where we left last time. We discussed about 0-10V basics, if you haven’t read that, you can read it here Basics of 0-10V and some interesting facts. Electrical outlet boxes can have numerous NM cables going in and out. This alternate type of wiring is no longer allowed by the NEC as of 2011 if a neutral wire is not present inside each switch box.ĭiagrams shown on this page are simplified for clarity. Since the white wire is hot, a black piece of electrical tape is placed on each end. The white wire carries line, the black wire carries the switched line. In the diagram below right, a 2- wire NM cable that connects the light fixture to the switch carries 2 line wires (one line, and one switched line). With optional light switch wiring, an NM cable supplies line voltage from the electrical panel to a light fixture outlet box.Īnother NM cable connects from the light fixture box to the switch box. ![]() Both line and neutral travel from the switch box to the light fixture box. With conventional light switch wiring using NM cable, a NM cable supplies line voltage from the electrical panel to a light switch outlet box.Īnother NM cable connects from this switch box to the light fixture box. ![]()
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