Hi,
I am having issues with electrical power in my garage (lights won't go on or door won't work). I checked power in one of the outlets and it's around 40~50V. Any idea what's happening?


Thanks

Yes, in past experience what you are describing has been the symptom of the loss of a neutral conductor connection. (the neutral conductor, or white wire is loose somewhere in the circuit)

First determine (test other outlets) if this low voltage (or high voltage) condition exists throughout the dwelling or just in the area of the garage. If throughout the dwelling it could be outside at the utility service connection. If just in a small area, check the connections at all the receptacles that test at a low voltage.

This is not an easy fix...good luck

btw, you never mentioned what type of electrical meter you are using...
digital meters can sometimes read a phantom voltage, in cases like this a solenoid style
voltage tester will give a more accurate result.

Start at Main Disconnect, to Panel, then Sub Panels. You need to Have 120 Volts between each Hot Leg and Neutral, Ground. You also need to check for 240 Volts across the 2 Hots. Verifying 120 on each Hot is not enough, If half of a 2 Pole Breaker is Tripped, voltage will go out on good half to the loads and read voltage on the tripped Half of Breaker.

No doubt you have sensors that detect any obstructions to the door working that can cut power to the opening mechanisms so I would also check those as well for proper alignment and clean lens. Probably should be first on the list of trouble shooting.

How Does a Garage Door Sensor Work? (http://www.overheaddoorgroup.com/blog/2013/how-a-garage-sensor-works/)


Check to see if there are any obstructions as this can be the cause of the malfunction. If the garage doorway is clear, you may need to either clean the lens or realign the sensor/sensors. If all of these options fail, contact a professional to look into the problem.

Loose wires, or stripped or broken plastic coupling gears are also prime suspects for garage door malfunctions.