Every electrical appliance has its own preset requirements. Even electronic appliances or what we refer to as consumer electronics have their power requirements. Water heater, air conditioner, washing machine or dryer, dishwasher, and refrigerator are large electrical appliances. All these devices have specific power requirements. When you check these appliances, you would find the wattage and voltage specifications mentioned on the label. You also need to know the amperage.
What’s on the Labels
A typical label on a water heater will perhaps tell you that it is a 5000W appliance running on 220-240V. This means the water heater will require an up to 240V power supply which is common in households and it will draw 5000W of electricity. Now, this means two things. One, you would have to ensure that a direct power line is dedicated for the appliance as sharing multiple appliances will interfere with the voltage. Two, you need to know the hot water heater amperage to determine the wiring so it doesn’t trip the circuit breaker by drawing more electricity per second. Drawing less is not an issue but drawing more will have the potential to cause a fire and hence circuit breakers are unavoidable.
What Type of Amperage Do You Need?
The higher you go on scales of voltage and wattage, the higher the amperage you would need. A 5000W water heater will obviously need a different kind of wiring and circuit compared to a 100W device. The circuit needs appropriate breaker, electrical connectors, and compatible wire to facilitate the hot water heater amperage. You should always consult an electrician, the installation guy from the water heater company or someone who is accustomed to these technicalities. Trying to do it yourself may backfire if you are completely new. Hire an electrician.
For the purpose of specificity and to give you some information, here is how you can determine hot water heater amperage. Let us consider a water heater that requires a dedicated separate connection of 220V and will consume 4500W of electricity. The voltage range of the connection may be 240V, that wouldn’t affect your calculation. A general rule of thumb is to divide the wattage by the voltage to get the hot water heater amperage. So you should divide 4500W by 220V and you will get 20.45amp. You shouldn’t opt for that specific amperage. You should go for 25 amp wiring and circuit with perhaps a two-pole circuit breaker. This is a generic take on hot water heater amperage and to give you an idea. The actual calculations will depend on the type of water heater, brand, specifications, and your local building codes as well as any fire safety standards that may be applicable.