What Is a 20A DP Switch and When to Use It
By Home Fashion Label - Extraordinary Products - Buster + Punch | Published: 2026-10-29
Category: Buying Guides
A 20A DP (double pole) switch is a heavy-duty switch that isolates both live and neutral wires, making it ideal for high-power appliances and safety-critical installations. Learn when and where to use one.
Quick answer
A 20A DP switch is a double-pole switch rated for 20 amps, meaning it disconnects both the live and neutral conductors for complete circuit isolation. Use it for high-power appliances like water heaters, ovens, or workshop machinery where safety regulations require both poles to be switched.
Why choose a 20A DP switch over a standard single-pole switch?
A standard single-pole switch only breaks the live wire. While that stops current flow, the neutral wire remains connected, which can leave a small risk of shock or appliance damage in certain fault conditions. A double-pole switch physically disconnects both wires, ensuring the downstream circuit is fully isolated. This is often required by electrical codes for fixed appliances over a certain wattage or in wet locations.
The 20A rating also matters: standard light switches are typically rated 6A or 10A. A 20A switch can handle the higher inrush and running currents of motors, heating elements, and compressors without overheating or arcing.
Where should you install a 20A DP switch?
Common locations include: next to a water heater or immersion heater, for a garbage disposal unit, for a workshop dust collector or large saw, for an electric oven or hob (if not using a dedicated cooker switch), and in commercial kitchens or laundry rooms with high-power equipment. Always check local wiring regulations, as many jurisdictions mandate a double-pole isolator for appliances that are not easily unplugged.
Are there any downsides?
The main trade-off is size and cost. A 20A DP switch is physically larger and more expensive than a standard single-pole switch. It also requires a deeper back box and heavier-gauge wiring (at least 2.5 mm² or 12 AWG). If you only need to control a light or a low-power fan, a 20A DP switch is overkill and won't fit standard shallow wall boxes.
Frequently asked questions about 20A DP switches
- Can I use a 20A DP switch for a 10A appliance?
- Yes, a higher-rated switch can safely control a lower-current load. The switch will not be damaged, and the appliance will operate normally. The only downside is the larger physical size of the switch.
- Do I need a neutral wire for a 20A DP switch?
- Yes, because the switch breaks both live and neutral, you need a neutral wire present at the switch location. This is different from a single-pole switch that only needs a live wire and a switched live return. Check that your wall box has a neutral wire before buying a DP switch.
- Is a 20A DP switch the same as a double-pole circuit breaker?
- No. A DP switch is a manual on/off isolator, not an overcurrent protection device. It does not trip on overload or short circuit. You must still have a properly rated circuit breaker or fuse upstream to protect the wiring. Always use a DP switch in combination with a correctly sized circuit breaker.
- Can I use a 20A DP switch outdoors?
- Only if the switch is rated for outdoor use (look for an IP rating, e.g., IP66). Standard indoor DP switches are not weatherproof. For outdoor appliances like a pond pump or garden lighting, choose a switch specifically marked for exterior installation. Check the IP rating before installing any switch outdoors.
Product spotlight
- 20A DP SWITCH: Sleek and slim with softly rounded corners, the Buster and Punch Electricity range combines functionality with stunning good looks. Available in 5 solid metal finishes. This 20A DP switch doesn't have to look industrial; you can match it to your decor with finishes like brass, bronze, or black, making a safety-critical component also a design feature.
20A DP SWITCH
