To find out if a dryer needs a neutral you need to check the nameplate and plug on the dryer.
A dryer will require a neutral wire if it operates on single phase power.
If the dryer runs on three phase power which is common with commercial dryers then may or may not need a neutral.
This post will help you determine if the dryer needs a neutral or not.
Dryer Wiring Information
A neutral is the return path for current in an AC circuit.
Single Phase Dryer
Single phase dryers typically have a live, neutral and earth wire. The color coding for these wires differs between countries. For the wire color codes in your country check here.
The live wire is typically either 120 volts (USA) or 230 volts (UK/AUS/NZ). The neutral wire should be 0 volts and the earth wire should also be 0 volts (this is using ‘ground’ as a reference).
The neutral has no voltage because it is earthed at the main switchboard.
With this being said the neutral still carries the same current as the live wire (unless some is leaking to earth). As the neutral doesn’t have voltage but still carries current it won’t give you a shock if it’s touched. However, if the neutral is removed it will spark and potentially give a shock.
The neutral is an essential wire in single phase AC circuits because it provides a return path for current to flow. Without it the dryer won’t work.
Three Phase Dryer
Three phase dryers are more common in commercial situations. There can be two different wiring configurations. One requiring a neutral and one without a neutral.
The first configuration is three live wires (one for each phase), a neutral wire, and an earth wire. A neutral is present because components such as relays or a display are present. These parts typically need a neutral.
The second configuration is three live wires and an earth. This is the classic three phase configuration. No neutral is required because the AC return path occurs through one of the live wires. These dryers are typically quieter and more efficient.
Does My Dryer Need A Neutral? – Job #1
Check The Nameplate On The Dryer
The nameplate on the dryer has key information about the electrical requirements of the dryer. The nameplate will have details about its power rating, required voltage, frequency and current. This information will help determine if the dryer needs a neutral.
The voltage is the main clue. If the voltage is 230 volts then it is single phase and will require a neutral.
If the required voltage is 400 volts and you see a ‘3N’ on the nameplate then the dryer is three phase and will require three phase cable with a neutral. N obviously stands for neutral.
If the required voltage is 400 volts without the 3N then you need a three phase cable without a neutral.
The nameplate is typically found behind the dryer which may not be convenient to get to. If the nameplate isn’t present or you can’t get to it then checking the plug is the next option.
Does My Dryer Need A Neutral? – Job #1
Check The Plug On The Dryer
Checking the plug will give you a clue as to whether or not the dryer needs a neutral.
If it’s a standard three pin plug which plugs into any household socket then we can say it is single phase. All single phase dryers need a neutral.
If the plug has four pins then it is likely that the dryer is three phase without a neutral. If the plug has five pins then the dryer will be three phase, neutral and earth.
Electricians Perspective
Standard household dryers are typically single phase and therefore require a neutral. Commercial dryers running on three phase may or may not require a neutral. Checking the nameplate and plug on the dryer will help ascertain its wiring requirements. We Fix Faults is a blog dedicated to finding and fixing common household electrical faults. For more information on dryer faults see here.