Rotary switches and selector switches are standard terms when discussing matters of control panels of industrial machinery. As a plant operator, it’s critical that you intimately know every switch on your control panel to ensure the safe and optimal running of the machinery.
If you have always felt somewhat confused during these discussions, you are not alone. Sometimes, rotary switches can be incorrectly referred to as selector switches and vice versa. This is because the two switch types might appear to function similarly, but they are pretty distinct. Let’s dig into the differences between rotary switches and selector switches.
Rotary vs. Selector Switches
In rotary switches, the contacts and connections will alternate as the spindle is turned clockwise or anti-clockwise. Conversely, in selector switches, the current is set on or off at varying currents as the handle is turned.
Rotary switches are often used to control multiple circuits with a single switch. Therefore, they eliminate the need to have different switches for each circuit, saving installation and maintenance costs.
Additionally, they save on control panel space as one rotary switch as one rotary switch can replace multiple conventional switches. Selector switches from manufacturers like APIELE commonly control the breaking or opening, making or closing, and changing of circuit connections. Only one circuit can be connected to each selector switch.
Contact Point Arrangement Differences
Rotary switches can be made of different materials with varying shapes and sizes. They also have varying contact point arrangements ranging from 3-pole 4-way and single-pole 12-way to 4-pole 3-way and 2-pole 6-way. Selector switches are available either as illuminated or non-illuminated switches. Their contact points arrangement can either be in 2 or 3 positions.
Most industrial machinery control panels feature both rotary and selector switches. However, rotary switches are also commonly implemented in medical equipment, computers, instrumentation, and aircraft equipment.
On the other hand, selector switches are also implemented in home automation devices, domestic appliances, public works, medical equipment, and commercial appliances.
Disadvantages of Rotary Switches
- Higher Cost:Due to their more complex nature, rotary switches often cost more to purchase, install, and maintain than selector switches. This higher cost can eat into the company’s bottom line.
- More Susceptible Mechanical Problems:Rotary switches have more components and complexity than selector switches. Therefore, there are numerous points of failures in these switches, making them more likely to develop mechanical issues.
Disadvantages of Selector Switches
- Limited Control: Since selector switches only have a maximum of 2 or 3 control positions, they aren’t very useful in operations where precise control is needed.
- Limited Functionality:With only one circuit per selector switch, its use in complex applications is pretty limited. Thus, they are unsuitable for use in complex control systems.
- Mechanical Wear:The contacts within selector switches can accumulate dust or wear down over time, negatively impacting their performance or resulting in a switch failure.
- Safety Concerns: Poorly designed/installed or worn-out selector switches can pose safety risks. The risk is magnified if the switch is connected to a circuit with a high-voltage current.