If you have an electric stove, you must give it a dedicated circuit. You will also have to use a high amp circuit breaker, but do you know exactly which size breaker to use? It depends on its capacity and other factors, but in general:
The industry standard for a simple modern electric stove is a 15-25 A two-pole circuit breaker (CB)in a 120V system. If it’s a large one, it may require a 30-40 A breaker instead, and if it’s an old one, a 10-15 A breaker may suffice. To know the exact right size breaker to use, choose one that has a rating at least equal to or a little higher than the value obtained by applying the following formula after ascertaining the stove’s power consumption in watts:
CB to use≥ Power x 1.2 / 120V
This article will help you choose the right size.
Why the Right Size Breaker Is Important
The right size breaker can protect an electric stove from overheating from dangerous current overload levels and electrical damage. Large electric stoves will require an exclusive circuit breaker and maybe even a dedicated circuit.
Using the right circuit breaker for your stove is important because if it is too small, it will have a thinner wire than needed, which can catch fire when used with a powerful stove. It will also trip too frequently. If it is too large, it will have a thicker wire than needed, which may fail to provide the safety for which circuit breakers are designed.
You can get this information about which size breaker to use from the stove’s manual by consulting an electrician or calculating it yourself. You can also get a general indication based on its size and features.
General Indications of the Breaker to Use
Choosing the right size breaker for an electric stove depends mainly on its capacity or amp requirement.
The amp requirement is reflected in the stove’s size and features. Generally, the larger the stove and the more features it has, you can expect the current draw to be higher. Conversely, if it’s a simple model with few features, it will typically have a low amp requirement, even lower if it’s an old model.
In general, we can divide electric stoves into three types: old, modern-simple, and modern-feature full models. The table below tells you what size breaker might be suitable.
Old Stove
Modern and Large with Several Features
Modern and Simple
Note that this is only what you might need to use. To know the exact size, you will need to gather specific information, including the stove’s capacity.
The Right Size Breaker for a Stove
To find out the circuit breaker size recommended by the manufacturer, look in the manual for your specific model.
You can easily obtain a copy online if you don’t have a hard copy of the manual. In the sample excerpt below, the information was found under ‘Specifications.’ This model (designed for the European market and incorporating an oven) requires a circuit breaker rated at 40 amps.
If you need to calculate the right size breaker to use yourself, the current capacity or amp requirement for its normal operation is the main thing you need to consider.
This can be calculated from the power consumption or wattage information usually mentioned in the stove’s product description. It normally ranges between 600W and 3,600W.
You need to divide this by the voltage (for a single-phase supply) and give some allowance for the rule that you shouldn’t use more than 80% of the circuit breaker’s maximum capacity. To work out the current (amps) your stove uses, apply the formula relating power, voltage, and current (P = IV) and the 80% rule for circuit breaker load:
Current the stove normally operates at = Power rating (in watts) x 1.2 / Voltage (of your power supply)
You will find that the higher the amp rating, the higher the breaker size you need to handle that capacity.
The calculation will normally give a value within the range shown in the table below for typical stove power ratings. The voltage supply is stable at around 120 V, and the supply is assumed to be single-phase (hence the 80% rule applied).
Circuit breakers usually come in values a few amps apart, so you may have to use one that is a few amps higher than the value you calculated. It should be a little higher anyway to consider the likely initial surge in current when the stove is first turned on.
Other Things to Consider
Besides the power consumption, you need to consider the following for a more accurate calculation specifically:
- The type of connection is either single-phase, as in normal domestic supply (assumed here), or three-phase.
- Distance – Generally, a lower gauge (thicker) wire is needed to cover a longer distance or for a higher current if the stove requires high power.
- Temperature – Ambient temperature in which the stove will be used. You must carefully cap the maximum allowable current to minimize the fire risk if it’s high.
- Voltage supply – The 110-120 V used in North America, which is lower than the European standard of 220-240V, produces higher amps and requires a higher-rated circuit breaker.
- Voltage drop – The voltage is usually tolerated within the range of ±5%. It will be higher if the distance is longer. Calculate the minimum and maximum values to ensure the circuit breaker covers them.
- The initial current surge is usually slightly higher before stabilizing at a lower level. The circuit breaker must allow for the maximum surge. If the surge is frequently high, you may find that you will need to use the next higher standard-size circuit breaker instead of the recommended one.
- Usage habit – If you use the stove on low settings all the time, it will draw less current than its maximum capacity and could operate with a smaller circuit breaker. If it is used intensively, frequently at high settings, and for long periods, then a higher circuit breaker must be able to accommodate that.
- Tripping – If you find that your circuit breaker is tripping too frequently, and the stove shows no sign of overheating or electrical damage, you may need to use a higher-rated circuit breaker.
Another important thing to know is that if the stove draws at least 30 amps, it should be arranged on a dedicated power circuit.
Wrapping Up
We considered what size circuit breaker should be used for an electric stove. We assumed it was for a single-phase 120 V system. Generally, a simple modern electric stove will require a 15-25 A two-pole circuit breaker. If it’s a larger one, it may require a 30-40 A breaker instead, and if it’s an old one, a 10-15 A breaker may suffice. The exact size CB must be at least: Power (in watts) x 1.2 / Voltage.
However, the next higher one may be necessary if you experience frequent tripping. In short, the right size breaker is neither too low that it would often trip or catch fire nor too high that it fails to protect against high current and temperature in the stove itself.
