Photo relay circuit: automatic street lighting, independent connection of the light sensor

It is more pleasant for owners of suburban housing to have lighting on the site. Manually turning on and off the lights every night is boring. Sometimes this opportunity is completely absent if the owners are not at home. Automatic control solves this problem. To connect the device, you need to understand the photo relay circuit, since the sensor is triggered by sunlight. Correct installation guarantees long and efficient automatic operation.

Criterias of choice

The purchase is the first thing to face. They acquire a photo relay based on its characteristics. Some parameters are required because they are fundamental. Neglecting them can make the device impossible to operate.

Required parameters:

• operating voltage;
• level of protection against external influences;
• permitted temperature for work;
• output power.

Lighting lamps are powered by 220 V or 12 V DC. Accordingly, the device must operate in one of these modes.

The sensor will be located outside, so protection from dust and moisture is required. Class - not less than IP44. This means that the device is not afraid of splashes of rain and particles with a diameter of more than 1 mm. Less security is unacceptable.

The operating temperature range should be as wide as possible. The domestic climate is characterized by severe frosts and heat. The sensor should not fail or melt.

The brightness of the lighting depends on the permissible power. The higher the parameter, the better it will be seen at night. Some systems are not designed for high-power lamps. Using them can cause damage to the wiring and fire.

Hosts should pay attention to the additional characteristics of the device, as they contain important points. Basically, these are auxiliary functions that improve the overall performance, adding value to the photo relay.

Extra options:

• sensitivity threshold;
• sensitivity adjustment limit;
• delay when triggered.

An outdoor light sensor for turning on the light should not have a high sensitivity, as this can lead to a false alarm. In winter, light reflects off the snow, and this can be perceived as dawn. The result is a spontaneous shutdown at the wrong time.

Sensitivity must be configured separately by users. Then, in different periods of the year, you can set different values, which will prevent false positives. The wider the range, the greater the possibility of fine tuning.

Delayed triggering allows you not to disconnect from the flash of light or its short hit on the photocell. This phenomenon occurs when a car is driven through at night.

Operation and search for installation site

The photo relay has a built-in sensor that opens the contacts of the electrical circuit when light hits it. This allows artificial lighting to work in an autonomous mode, depending on the amount of light outside.

Sensor types:

• built-in - installed together with the relay on the electrical panel;
• remote - located separately from the body.

Preference for a specific type should be given with an eye to local conditions. A system with a built-in sensor is easier to install, while a remote one can be more efficient. Or the first one cannot be delivered due to the proximity of the carriageway.

Choosing a location is a defining occupation. The correct operation of the device depends on the environmental conditions. If placed incorrectly, manufacturers cannot guarantee that there will be no false positives.

Installation rules:

• the sensor must be exposed to direct sunlight;
• maximum distance from artificial lighting sources;
• it is undesirable for headlights from passing cars to hit the photocell;
• accessible place for service.

Finding the best place can be extremely difficult, so you have to spend time on it. All options must be considered. Perhaps this will require construction work, additional communications. The location of the sensor will often have to be changed during operation after identifying shortcomings in its operation at a particular place.

A common mistake is installing a photocell to turn on the light on the pole where the lantern is located. In winter, the sensor will be covered with ice and will not be able to work correctly. We'll have to climb to a height to clean it. In summer, the working surface of the device will suffer from dust. In addition, the photo relay housing for such a place must be well protected from the effects of precipitation at any time of the year.

The ideal place is the wall of the building. The overhang of the roof will provide protection from precipitation. The main thing is that the sensor looks away from the road and does not point to the north. The ideal direction is east or south.

Electrical connection

It is easy to connect the device to the street network. Manufacturers put instructions in a box, but often they are in a foreign language - Chinese or English. A professional engineer can figure it out, but not a layman. We'll have to understand the photo relay circuit by studying a little information. The option is the same for all devices.

Connection diagram:

• a phase or ground is introduced into the input;
• from the output, a contact is applied to the load - these are lighting devices;
• grounding is carried out from a machine or a bus.

This is a standard connection principle with a minimum set of equipment. The wires are connected in a junction box. It is also called editing room. The model must be airtight. It is usually installed on the street.

Connection options with third-party equipment:

• a junction box is required to enable / disable a powerful lamp with chokes. A contactor is included in the circuit. The device tolerates starting current well and is designed for a large number of on / off operations;
• the motion sensor allows you to supply electricity to the lamp only when a person is near it. Common installation locations are toilet, courtyard entrance, outside the front door. On the diagram, first a photo relay is put, and then a motion sensor. This will only work in the dark.

Additional equipment must be reliable so that it does not interrupt the operation of the entire system. You should not buy cheap Chinese devices, since they often fail in domestic conditions.

Wire system

Wire markings are internationally standardized. Connecting a light sensor for street lighting with this approach of manufacturers is not difficult. There are few wires and it's easy to figure out their purpose.

Pin designation:

• red - lamp power;
• blue (sometimes green) - this is the zero of the power cable;
• black or brown - phase.

The circuit will be working only when the neutral wire is connected to the lamp. This is necessary to stabilize the operation of the system so that the light source does not burn out during overloads.

Equipment setup

The equipment should be checked after installation. To stabilize the work, you will need to adjust some parameters. The main one is sensitivity. How the device will react to lighting depends on it, depending on its degree. Therefore, connecting a photo relay is only half the battle.

Light sensitivity adjustment is done with a plastic rotary dial. It is usually located at the bottom of the case, but there are other location options. Nearby should be arrow-shaped designations that reflect the directions for adjustment. To the left is a decrease in sensitivity, and to the right is an increase.

Initially, lower sensitivity is set in the extreme right position. Adjustments are made in the evening, when you would like to turn on the light. The regulator is turned smoothly until the light comes on.