Multiply the value for current by 125.
Breaker size for electric hot water heater.
1 or 2.
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Thus the current draw for a 1 500 watt heater is 12 5 amps.
This happens because 20 amp from the water heater is more than 80 of the breaker capacity.
So it will work consistently and in a stable way.
You can estimate the necessary tank capacity in gallons based on the number of people in the house.
For example a 20 amp hot water heater needs 12 gauge wire a 25 amp hot water heater requires 10 gauge wire and a 30 to 40 amp hot water heater requires 8 gauge wire.
Wire a hot water heater with wire that s sized to accommodate the heater s current requirement.
If you can plug the heater into a regular wall outlet the specified voltage should be 120 volts.
But with a 25 amp breaker the 20 amp water heater will only cover 80 of the total capacity of the circuit breaker.
In the above example we would require a 15 6 amp circuit breaker for our us readers.
First lets start with the nec code for this water heater application.
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.
Electric water heaters require a 240 volt dedicated circuit which serves only the water heater and no other appliances or devices.
So it won t work as effectively as it needs.
The circuit wiring typically includes a 30 amp double pole breaker and 10 2 non metallic nm or mc cable.
Multiply the current rating of the water heater with 125.
Instead you need at least 25 amp.
Just follow the three simple steps below to choose the right model and size you need.
Some large heaters draw up to 50 amps requiring 6 gauge wire.