Have you ever used a switch to start an electric motor? And reversing switch? In the World of Electrical, in this article we teach step by step how to install a switch to start a gate motor. Come on!
Many electricians do not know how to turn the electric motor on, off and reverse the direction of rotation using the motor switch. To start a motor with a switch, the connection must be made with a switch suitable for use in electric motors. The main function of a switch is to interrupt the passage of an electrical current as needed.
There are numerous types of motor switches on the market, but in general motor, switches are designed to switch the motor on, off and reverse the direction of rotation. The motor switch is different from the simple lamp switch, as the function of a simple switch is to switch a lamp or set of lamps on and off.
Below we have a model of motor switch that has two buttons to choose the direction of rotation of the motor. The switch buttons are mechanically interlocked, that is, if you press one button, the other switches off instantly, avoiding the wrong closing of the motor coils. It also has a central stop to turn the engine off in any direction.
This switch is widely used in electric gate motors or motorized shutter motors.
Engine Switch – Connection
Connecting a motor with a motor switch is very simple. The motor switch below is bipolar, so on the back of the switch we have two sets with three contacts, one set for each phase in the case of two-phase motors, but only one set of contacts can also be used in the case of a single-phase motor.
In our diagram, we will install this switch to start a gate motor. The gate motor will be connected in single-phase 127v and the motor has three cables, one common for neutral and the other two for each direction of rotation of the motor, one for the left and one for the right.
In the passage box we have already installed the support for the switch. We have five cables in the box, the black cable is phase and the blue is the neutral of the power supply, plus two gray cables of return for the motor, besides another neutral cable that goes straight to the motor.
Before starting the connection always remember to turn off the circuit breaker and check if there is electrical voltage in the circuit, to carry out the installation safely. The first thing before turning on the switch will join the two neutral cables. For this we use a twist connector, just strip the two blue wires, unite and place the twist connector.
The black phase cable is connected to the central contact of one of the switch contact sets. The two gray return cables are connected to the contacts at the end of the switch in the same set of contacts that the phase cable was connected to.
Now just connect the cables coming from the switch and the neutral cable to the motor cables, for that we will use a union connector. The blue neutral cable that comes from the passage box, must be connected to the blue cable of the central terminal of the motor union connector.
Now the gray cables that come from the switch to the motor must be connected to the black and white wires of the motor. First connect a gray cable to the black cable of the lower terminal of the motor union connector and the other gray cable to the white cable of the upper terminal of the motor union connector.
After making all connections, we can place the switch in the passage box. The switch is modular, so the switch is inserted into the holder by pressure, just position and push. In the vacant space we will put a lid, just position, push and finally just put the finishing lid.
Now that we have completed all necessary connections, we can turn the circuit breaker back on to test the circuit. First we will start the engine on one side, then using the central stop we will turn off the engine, then start the engine in the other direction. We recommend turning the engine off to change the direction of rotation, as reversing the direction of rotation can further force the engine, thus reducing the engine’s service life.