How to connect the LED spotlight

LEDs as lighting and display elements have almost superseded incandescent lamps from their main field of application. Competitive advantages of LEDs are long life and cost effectiveness. Nowadays such lights are used, including for lighting streets and territories, artistic lighting of buildings, etc.

How is a spotlight

LED floodlight (at home is used wrong name diode - such a term to use, at least unprofessional) is arranged simply. Like an ordinary lamp with an incandescent bulb, it contains:

• housing;
• Light-emitting element (a single high-power LED or a matrix of several less powerful devices);
• terminal for connecting the power cable (terminal block, connector);
• glass, covering the compartment with LEDs (diffuser).

Device of LED-lighting.

Unlike its predecessor with "Ilich bulb", LED-light contains another detail - the driver. Powerful projectors have it in the form of an electronic circuit, stabilizing the current through the light-emitting element. Smaller lights may have a resistor as a driver. Since the emission of LEDs does not depend on the degree of heating, they are installed on a heat sink to extend their life.

Connecting to the power grid

To connect most lighting devices to a single-phase 220 V mains supply, they are equipped with three terminals:

• phase (designated L);
• neutral conductor (N);
• PE conductor ().

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Obviously, an electrical circuit with TNS neutral mode must be used for connection. The peculiarity of this mode is that it consists of phase conductors, neutral (N) and protective (PE). In this case, the wiring diagram of an LED spotlight with three wires is simple - phase conductor to phase, neutral conductor to zero, ground conductor to PE. The same applies to the TNC-S system. With it, the neutral and protective conductors are separated at a certain point, usually at the building entrance. Many networks, however, are based on the obsolete TNC system, where the neutral and protective conductors are combined.

According to the rules, lighting devices that do not require grounding must be used in these networks. Such devices include those with protection class:

• 0 - protection provided by a single layer of insulation, the least safe option;
• II - devices with double or reinforced insulation, are much more expensive;
• III - devices powered by extra-low safety voltage (below 50 VAC), they are out of the scope of this article.

Important! You can determine the protection class of an electrical appliance by its passport, technical specification or marking:

• 0 - not marked;
• I - grounding symbol or the presence of ground terminal itself;
• II - double insulation symbol ;
• III - symbol of class III protection .

In Class II devices, safety is ensured by having a protective earth, and using them in a TNC network without an earth connection is against regulations and can lead to unfortunate consequences if the basic insulation is broken and the luminaire body is exposed to voltage. It is also against regulations to connect the grounding terminal to the working neutral conductor (N, PEN).

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How to make a spotlight yourself

 

At his own risk, an electrician can connect a device of protection class II without connection to the protective ground. And the spotlight will even work. But he should remember that the consequences will be on his conscience. He may even have to answer to the law.

Important! Grounding by itself does not ensure safety. The power circuit should be equipped with a circuit breaker to provide protection if the basic insulation is broken. If possible, a residual current device (or a residual current device) must also be used.

Tools and materials required

To connect the luminaire, you will need ordinary electrical tools:

• pliers to cut the power cable;
• a box cutter to strip the cable sections;
• screwdriver to connect the ends of the wire to the terminals.

Pliers for electrical wiring.

These are enough to make the connection. But a professional would recommend more:

• a special insulation puller;
• lugs for wires of the appropriate diameter and a tool for crimping.

If the installation is carried out with stranded wire, the stripped areas are good to tin - for this, a soldering iron comes in handy.

And, of course, you need an electrical cable with the appropriate cross-section. For 220 V it can be selected from the table according to the power of the spotlight:

Important! When selecting a cable, you must consider the power consumption of the luminaire, not the equivalent (corresponding to the power of the incandescent lamp).

Wiring diagram

Connecting the LED spotlight to the power grid can be done through a conventional socket. To do this, you must install a plug at the supply end of the cable. If using a luminaire of protection class II, the socket and plug must have a grounding contact.

Scheme with motion sensor

In order to save energy, lighting fixtures are connected to work in conjunction with a motion sensor. The spotlight is powered only when a moving object (person, car) is detected. In this case, the sensor is connected in the gap of the phase wire, in series with a normal switch.

Connecting the motion sensor.

Main power switch turns off the spotlight regardless of the state of the motion sensor. When the power is turned on, the spotlight works automatically. The problem with this circuit is that the sensor contacts are not designed for high current, and if the lamp is powerful, they will start to burn out after a while and the sensor will stop working. To avoid this, you must connect the spotlight through an intermediate relay or magnetic starter. The sensor will turn on the relay and the relay will turn on the illuminator.

Connect the motion sensor through an intermediate relay.

Important! A bad solution would be to connect two motion sensors in parallel to reinforce the contacts. It is not possible to activate both together, because of the difference in switching level, and both motion detectors will fail.

How to connect via a switch

A less successful scheme is to connect a motion sensor in parallel with the main switch. In this case the closing of contacts of the switch blocks the circuit of automatics.

Parallel connection of the switch to the sensor contacts.

In this variant it is not possible to remove power from the illuminator in case of motion sensor failure (contact sticking).

Wiring recommendations

When connecting the spotlight, it is advisable to use a cable with standard colors of wire insulation and follow the connection sequence.

Single-phase load cable with grounding conductor.

• The red wire is connected to the phase terminal (L);
• The blue wire connects to the neutral conductor (N);
• green-yellow to ground (PE).

This order must be observed on both the power supply side and the consumer side (luminaire). Of course, for electric current, the color of the core does not matter, and if you do not comply with the correct connection by the color of the insulation, nothing will happen - the spotlight will work just as well. But compliance with the rules indicates the professionalism of the installer. And in the future, if there is a need to repair or reconnect, it will be easier for another installer to figure out the diagram.

If the wiring passes through the street, in order to ensure vandalism, it makes sense to lay it in pipes. In this case, it should be understood that the conditions of heat dissipation will be worse than in the option with open laying. If the calculations show that the load capacity is close to the upper limit for the selected cross-section, the diameter of the wire should be increased at least a step. It is even more correct in this case to specify the parameters of the conductors in PUE.

Installation of electrical wiring in a metal pipe.

Safety measures and rules of operation

At any work with electrical installations it is necessary to observe the main rule - all actions should be carried out with the power off. The absence of voltage must be checked with a pointer directly at the place of work. The electric tool must be in good condition and have no damage to the insulation. It is even better to use protective equipment against electric shock even at home - dielectric gloves, carpets, galoshes. You can never have too many safety measures.

During operation, it is also necessary to ensure the integrity of the insulation of the wiring and switchgear. If any damage occurs, the light must be taken out of service until the fault is corrected.