A range hood doesn’t need a dedicated circuit for any special reason relating to the range hood.
However, the circuit that the range hood is plugged into must be able to handle its full load current and the full load currents of any other appliances on the same circuit.
This post aims to give you four different considerations when wiring for a range hood.
Range Hood Wiring Overview
A range hood can either be hard wired or have a plug. It will be plugged into a power outlet. This power outlet will be wired with a cable that originates in the switchboard. In the switchboard this cable will terminate into a circuit breaker or fuse.
Circuit breakers are used to protect people and property from electrical faults like short circuits and overloads.
A circuit breaker will shut off power to the circuit when either of these faults occur. For this post, we are interested in overloads.
An overload occurs when too much current is drawn through a circuit. This excess current causes the cable to heat up.
The cable can heat up until it eventually melts the insulation and catches on fire. As cables are located in places where we cannot see them such as in wall cavities and ceilings it’s important to have protection devices (circuit breakers) that will shut off power when this occurs.
For this reason, a circuit breaker will trip at the current carrying capacity of the cable.
A cable with a large diameter is able to handle more current without heating up than a smaller cable. This is why an oven is wired with a much larger cable than a light, for example. Each cable will have a circuit breaker set to trip at its current carrying capacity.
As you can see we need to know how much current is consumed by appliances before determining how large a cable should be and whether an appliance needs to be on its own dedicated circuit.
With this information in mind, let’s look at four things to consider when wiring for a range hood.
1. Check Range Hood Electrical Specifications Online
The electrical specifications for the range hood can be found in the installation manual.
If the manual isn’t available it can probably be found either online or on the manufacturer/retailers website.
We need the electrical specifications to determine the operating current of the range hood. This information will help us determine the size of the cable we need to install.
The electrical specifications will tell us key information like:
- The operating voltage – problems happen when this deviates such as during power outages.
- The frequency.
- The operating current.
- Fuse rating.
We are interested in the operating current. If the range hood draws 3 amps, the cable must handle this and the current of any other appliances on the same circuit.
2. Check Loading From Other Appliances On The Same Circuit
The operating currents of other appliances on the same circuit need to also be taken into account.
Appliances which are used at the same time as the range hood are especially important. An oven will be on a separate circuit but it is possible that other appliances will be used at the same time such as microwaves or fridges.
3. Choose Cable Size
As mentioned earlier, larger cables can carry larger currents.
A standard domestic wall outlet is typically wired with 1.5mm2 or 2.5mm2 cable.
1.5mm2 cable is typically fused at 16 amps and 2.5mm2 cable is fused at 20 amps. These are common cable sizes for power outlets which a range hood may be plugged into.
If a range hood draws 3 amps, there is still a decent amount of capacity available for other appliances on the same circuit. Refer to the electrical specifications for your particular range hood for the operating current relevant to you.
4. Cable Circuit Breaker
A circuit breaker needs to be correctly rated for a cable’s current carrying capacity.
This means that a breaker will shut off power to the circuit when this current is exceeded or overloaded.
As mentioned before, 1.5mm2 cable will have a breaker rated at 16 amps which will trip just above 16 amps and a 2.5mm2 cable will have a breaker rated at 20 amps which will trip just above 20 amps. If a 32 amp breaker was put on a 20 amp cable, the cable would catch on fire before the breaker trips. This is why the correct circuit breaker is vital.
Electricians Perspective
For AS/NZS:3000, a rangehood doesn’t need a dedicated circuit, but the circuit must be able to handle its operating current and be protected against overload and short circuit.
For other countries such as the USA, it may be necessary to have a range hood on a dedicated circuit according to local rules.
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