Does a motion sensor switch need a neutral?

Asked By: Ehsan Dempewulf | Last Updated: 5th April, 2020
Category: home and garden smart home
4.5/5 (481 Views . 18 Votes)
Picking a Motion Sensing Switch
The most important consideration is the necessity of a neutral wire. Some motion sensing switches require that there be a neutral (white) wire attached to them, some do not—for those that do there is no substitute.

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Also, do occupancy sensors need a neutral?

Occupancy sensors require standby power to operate the sensor when the load is "off". To do that it needs a path to Neutral; some models require Neutral, others require Ground (which is used to draw power, but the current is less than 1ma is considered harmless).

Similarly, how do you wire a motion sensor switch? Table of Contents

  1. Step 1: Turn Off the Power.
  2. Step 2: Test the Wires, and Remove the Switch.
  3. Step 3: Cut the Wires.
  4. Step 4: Strip the Black and White Wires.
  5. Step 5: Connect the Wires to the New Switch.
  6. Step 6: Tuck Wires Into the Box, and Secure the Switch.
  7. Step 7: Customize the Controls, and Reinstall the Wall-Plate.

People also ask, does a motion sensor light need a switch?

Again, one must check the manufacturer's instructions for motion-sensor type lighting. If the manufacturer's installation instructions require a switch, then it must be installed. Allowing the motion sensor without the switch would be a violation of NEC Article 110.3(B). Usually those motion sensors require a switch.

What happens if you do not connect the ground wire?

In the absence of the ground wire, shock hazard conditions will often not cause the breaker to trip unless the circuit has a ground fault interrupter in it. If the case is grounded, a high current should flow in the appliance ground wire and trip the breaker.

38 Related Question Answers Found

What does no neutral required mean?

The neutral wire allows the completion of the circuit and the switch to have power even when it's turned to the off position when you want the lights off. Without this neutral wire in place, the circuit is broken any time the switch is now in the off position.

What if my light switch has no ground wire?

Going without a ground wire
If the light switch has a screw for a bare ground wire but your electrical box doesn't have one, you're OK just leaving that screw empty and connecting your other wires to the hot screws. If the box isn't grounded, the switch will still work.

What is the difference between occupancy and vacancy sensor?

An occupancy sensor turn lights ON automatically upon the detection of motion then turns the lights OFF automatically soon after an area is vacated. A vacancy sensor does not offer an option of automatically turning lighting on requiring a manual button press from the occupant (manual/vacancy mode).

What is an occupancy sensor switch?

An occupancy sensor is an indoor motion detecting device used to detect the presence of a person to automatically control lights or temperature or ventilation systems. Occupancy sensors are typically used to save energy, provide automatic control, and comply with building codes.

How far can a motion sensor detect?


Keep in mind that most motion sensors can detect between 50 and 80 feet. Most burglars enter the home through a front or back door, patio door, or garage door, so it's advisable to place the sensors near those areas.

Why does my sensor light not turn off?

Most motion sensor lights have a built-in “override” mode. What to do: Shut the lights off at the breaker and wait a full 30 seconds before turning the power back on. After this, the security light should come on for a short while then turn off again and go back to normal settings.

Do motion sensor lights deter burglars?

Motion-activated lights are an important layer of home security. It is true that lights cannot stop a criminal in the physical sense. The illuminating effects of outdoor security lighting can also serve as a crime deterrent by removing the cloak of darkness that burglars and other home intruders prefer to hide in.

Can wind set off motion lights?

The wind itself cannot Set Off a Motion Detector directly, but it can cause other objects to move. These moving objects will then cause the Motion Sensor to trigger. If you're worried about wind movement, consider where your sensor is being placed.

Can you wire two motion sensors to the same light?

In order to have more than one motion sensor or motion detector turn on the same group of lights it is necessary to wire the motion sensors in parallel with each other, in the same manner as the lights are wired. As long as at least one motion sensor is detecting motion, the lights will remain on.

Why does my sensor light keep coming on?


Reset the power to the light by turning the power off at the wall switch or breaker for 3 seconds and turning the power on. Replace the dimmer or timer with a standard on/off wall switch. ? The motion sensor may be picking up a heat source, such as an air vent, dryer vent, or brightly painted, heat-reflective surface.

Why does motion sensor light stay on?

Often, the wind blowing through leaves and branches can cause the motion sensor to detect motion, causing the light to stay on. Turn off the switch which operates the motion sensor light. Keep the switch off for 1 to 2 seconds and then turn the light switch on again.

How do you stop a motion sensor light from turning off?

Most motion detectors have a built-in override:
  1. Normally the switch is kept on all the time.
  2. If you turn the switch off and on within a second or so, the light will stay on, and this overrides motion detection.
  3. To go back to normal operation, turn the switch off and wait ~10 seconds, then turn back on.

Can a light work without a neutral?

Yes, there are a few… (read very, very, very few) switches that don't require a neutral, but those will limit you to incandescent only. The black “hot” connection is broken to turn the light on/off, the white “neutral” connection completes the circuit. The bare (hopefully) solid copper wire is the ground.

Can you add a neutral wire to a light switch?

Adding a neutral wire to a light switch will require you to find where the neutral wire is located in your lighting circuit and then route that neutral wire back down to your light switch. Typically you will find a neutral wire at outlets or on the other side of a light fixture.

Does the neutral wire carry current?


To sum up, a live wire carries the full load current, while a neutral wire carries some current, only when the loads are not balanced. The neutral wire is at approximately 0V but to be safe you must NEVER touch this wire either. If the wiring is faulty it may be carrying the same electricity as the live wire.

What is the purpose of neutral wire?

The neutral wire is often confused with ground wire, but in reality, they serve two distinct purposes. Neutral wires carry currents back to power source to better control and regulate voltage. Its overall purpose is to serve as a path to return energy.

Do all houses have neutral wire?

US houses built from the 1980s on Usually have a neutral at the switchbox. Beginning in 2011, the national electrical code required a neutral at almost all switch boxes.