Hot Water Heater Circuit Breaker Size
You have stated that the calculated amperage load for 4500watt at 240volts is 18 75amps however nec article 422 13 states that the minimum circuit rating for a water heater must be 125 of the rated load so this 4500watt load requires a minimum circuit of 23 44 amps at 240volts.
Hot water heater circuit breaker size. But with a 25 amp breaker the 20 amp water heater will only cover 80 of the total capacity of the circuit breaker. Cb size for 30a non contentious load. Now in order to choose an electric breaker multiply the current draw of the water heater with 125 per cent in order to determine the size of the breaker you will need. Multiply the value for current by 125 percent to determine the size of the breaker you need for the heater.
Electric water heaters require a 240 volt dedicated circuit which serves only the water heater and no other appliances or devices. An exact 100 rated for 30a circuit breaker can be used for 30a non continuous load. The 15 amp size breaker is used in general circuit wiring. A diy plumbing water.
So you go and reset the circuit breaker. The 20 amp size breaker is used for dedicated appliance. In other words a load circuit having 24a the appropriate size of breaker would be. This happens because 20 amp from the water heater is more than 80 of the breaker capacity.
In north america the standard sizes for breakers are 15 20 30 and 40 amps. This way a 30a circuit can be safely used for 24a circuit. 24a 0 8 30a. Then after a few.
So it won t work as effectively as it needs. In the above example we would require a 15 6 amp circuit breaker for our us readers. The circuit wiring typically includes a 30 amp double pole breaker and 10 2 non metallic nm or mc cable. Now lets consider this water heater circuit installation.
Your water heater trips the circuit breaker in your house. How to easily repair fix troubleshoot an electric water heater that trips the circuit breaker or blows fuses little or no hot water. Instead you need at least 25 amp.