A double pole switch serves a vital role in ensuring safety and functionality, particularly in high-demand applications. This article looks at what these switches are and when they should be used.

Double pole switches explained

A double pole light switch is designed to control two separate circuits simultaneously. Unlike a single pole switch that manages just one live wire, a double pole switch has two sets of contact points (called poles) for breaking and connecting two circuits. This allows the switch to break both the live and neutral wires, providing an extra layer of safety by ensuring that both poles of the circuit are disconnected when the switch is in the off position.

That means the wiring after the switch is just metal strips that cannot possibly have any current flowing through them. Of course, if you’re working on wiring after the switch, you should still test it before working on it – never assume any electrical component has been installed correctly.

Double pole switches are typically rated for higher currents and voltages, making them suitable for appliances that consume significant power, such as electric cookers, water heaters and industrial machinery.

In summary, double pole switch allow:

  • Two separate circuits: Each pole allows the switch to manage two independent circuits, which can be vital in ensuring complete disconnection in high-power applications.
  • Enhanced safety: Double pole switches offer enhanced safety by preventing the potential electrical hazards of a single-pole switch that only disconnects the live wire.
  • High current and voltage handling: These switches are designed to handle higher electrical loads, making them suitable for demanding applications that require robust switching mechanisms.

Types of double pole switches

Double pole switches come in various forms, including:

  • Double pole single throw (DPST) switches: These switches control two circuits with a single action. The circuits are either both off or both on.
  • Double pole double throw (DPDT) switches: These provide two positions for each pole, allowing the switching between two different circuits or states, making them versatile for complex wiring needs.

Alternatives to double pole switches

The main alternatives to double pole switches are single pole switches and triple pole switches, each with its own set of applications and limitations.

Single pole switches

Single pole switches control only one circuit and are primarily used for lighting and low-power applications. Where both the live and neutral wires need to be disconnected to ensure safety (or where higher voltages and currents are involved), single pole switches are inadequate. They only break the live wire, leaving the neutral wire connected, which can still pose a risk of electrical shock or fire.

Triple pole switches

These switches can control three separate circuits and are primarily used in specialised industrial applications where multiple circuits need to be managed together. Triple pole switches are more complex and generally unnecessary for standard applications that require double pole switches. Their additional complexity and cost don’t justify their use in simpler setups.

Why alternatives may be inappropriate

When it comes to home electrical systems (or some industrial applications), using the wrong type of switch can lead to significant risks and inefficiencies.

Safety concerns

In high-power applications like electric ovens or industrial machinery, ensuring both the live and neutral wires are disconnected is crucial. Single pole switches, which only disconnect the live wire, leave the neutral wire connected, creating a potential for electrical shock or short circuits if the circuit is touched or develops a fault. The double pole switch reduces this risk by completely isolating the appliance or machine from the power supply.

Regulatory compliance

Various electrical codes and safety standards require the use of double pole switches in specific applications. For instance, many residential codes say double pole switches should be used for certain high-voltage appliances (e.g. cookers) to ensure disconnection and safety. Using single pole switches in these instances not only compromises safety but also may violate regulations.

Load management

High-demand electrical applications, such as electric water heaters or heavy industrial equipment, draw large amounts of power. Single pole switches are typically not rated to handle such loads effectively. 

Circuit integrity

Certain complex systems need the ability to isolate multiple circuits simultaneously to maintain system integrity and reliability. Triple pole switches may sometimes be necessary, but they could just mean extra cost for applications that only need dual-circuit control.

Find high quality double pole switches 

At ACAS Electrical, we pride ourselves on providing expert advice and top-quality electrical components tailored to your needs. Whether you’re powering a new industrial installation or upgrading residential appliances, our range of double pole switches ensures you have the right tools for the job. Contact us today to learn more about our products and how we can help you achieve safe and efficient electrical solutions.