What is a lighting contactor?
The lighting contactor is a special type of contactor that can be used individually for simple control schemes or as integral components in full-featured lighting control systems. It provides reliable and efficient means of local or remote switching of lighting as well as non-inductive loads.
A lighting contactor is designed to provide a safe, convenient means for local or remote switching of tungsten (incandescent filament) or ballast (fluorescent and mercury arc) lamp loads. It is also suitable for other loads such as low-pressure and high-pressure sodium lamp loads and other non-motor (resistive) loads. It is not recommended for most sign-flashing loads.
The lighting contactor is designed to withstand the large initial inrush currents of tungsten lamp loads without contact welding.
What does a lighting contactor do?
Lighting contactor has evolved from the need for more than simple on-off manual control of lights. The purpose of a lighting contactor is to control the lighting remotely from some distant location.
A lighting contactor is an integral part of any energy management system. It helps conserve energy consumption and reduces utility bills by providing three types of control. It offers both centralized and remote control of the lighting. Circuits can be turned on and off from a number of remote locations in addition to a master control station. It also offers selective switching of lights.
Selective switching is the control of one or more individual lighting circuits, independent of the other circuits. This design allows the potential for turning on only the amount of lighting that is actually needed. A lighting contactor can provide automatic control to ensure that lights will be turned off when not needed. There are a number of devices that, when used with lighting contactors, offer a convenient and reliable method of automatically controlling lighting loads: programmed time clock, photoelectric cell, programmable controller, and demand controller.
How does a lighting contactor work?
Lighting contactors have two types: Electrically held and mechanically held.
Power should be continuously supplied to the coil for contactor operation in the electrically held versions. Their working principle is similar to power contactors.
But the working principle of a mechanically held contactor is a bit different. Mechanically held contactors have two different coils, a latching coil, and an unlatching coil. (Sometimes have just one coil to latch and unlatch) These coils are only momentarily energized to engage or disengage the power contacts.
With electrically held, one input is required, but with mechanically held, two inputs, one to close and one to open are required.
The main characteristics of lighting contactors are:
- Electrically and mechanically held
- 2–12 pole versions
- 30–800 A lighting ratings
- Easy installation
- Less space occupied
- Most contactors have built-in auxiliary contacts
- Wide range of coil voltages from 24 to 600 VAC 50/60Hz
- Panel and DIN rail mounting
Full line of enclosures including NEMA 1, 3/3R, 4, 4/4X stainless steel and 12
Lighting contactors offer a time-proven design for better electrical and mechanical performance. They are used wherever reliable, convenient, and economical control of indoor and outdoor lighting is required.
Typical installations include:
- Parking lots
- Industrial plants
- Office buildings
- Theaters and auditoriums
- Hospitals and institutions
- Shopping centers
Installation of lighting contactors
For new installations, lighting contactors can either be installed right into the lighting panelboard or in their own enclosure next to or remote from the panelboard. In existing applications where the lighting control system is being updated, lighting contactors can be installed in their own enclosure next to a lighting panelboard.
Lighting contactors are available open or mounted in Type 1, 3R, 4, 4X, and 12 enclosures.
Type 1 is for indoor, general purposes for personal protection. Knock-outs are provided at the top and bottom for conduit entry.
Type 3R is for outdoor applications and is rated for rain, sleet, and external ice buildup. Type 3R enclosures have knockouts at the bottom and provisions for a hub at the top.
Type 4 and 4X are for mounting indoors or outdoors and provide protection from splashing water, hose-directed water, and windblown dust. Watertight conduit hubs are provided at the top and bottom of Type 4X enclosures. The standard Type 4X enclosures are made of 304-Grade stainless steel, providing corrosion protection. 316-Grade stainless steel construction is available as an upgrade option.
Type 12 enclosures are for indoor mounting and protect from dripping liquids, falling dirt, and dust. No knockouts or hubs are provided with Type 12 enclosures.