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View Full Version : How to add 110 circuit breaker or new sub panel


sherihonda
Jun 5, 2009, 01:39 PM
I bought a 120v 2000 watt hot water heater. This calls for a 25 amp breaker. I only have 1 free 15 amp. Would it be better to replace the breaker or put in a subpanel? I also have my stove connected to a double 30 amp 220. Which route would be best, and could someone explain in detail how to do it. I understand all about cutting the main and the danger of current still in main wires.
Thanks,
Sheri

creahands
Jun 5, 2009, 06:50 PM
What do u mean ''have 1 free 15 amp''?

Chuck

sherihonda
Jun 6, 2009, 06:40 AM
I'm sorry, my mistake. It is actually a double pole 30 amp 220 breaker.

creahands
Jun 6, 2009, 11:19 AM
Uhave a double pole 30amp/220 breaker not in use?

Chuck

ohb0b
Jun 6, 2009, 11:36 AM
I bought a 120v 2000 watt hot water heater. This calls for a 25 amp breaker. I only have 1 free 15 amp. Would it be better to replace the breaker or put in a subpanel? I also have my stove connected to a double 30 amp 220. Which route would be best, and could someone explain in detail how to do it. I understand all about cutting the main and the danger of current still in main wires.
Thanks,
Sheri


You may remove the spare 15 amp single pole breaker and install a 25 amp breaker.

The breakers are "stabbed" into the bus (held by spring loaded clamps) You just pull to remove.

Most home improvement stores have service panel displays. You can practice removing and installing the breaker at the store.

donf
Jun 6, 2009, 11:38 AM
Sheri,

Just from your minimal discussion I suspect that you are not used to working with electricity.

How did you determine that the water heater needs 25 amps? Please read the metal label on the back of the heater to get the voltage, amperage or wattage needed by the water heater.

You can calculate the correct amperage by dividing the wattage (2000) by the Voltage (120) to get amperage. 2000/120=16.6 amps. Because this is a water heater, the amperage must be multiplied by 1.25%. The heater would be defined as a constant on device, that means you would need the breaker sized for 16.6 * 1.25% = 21 amps. That's the reason you would need a 25 amp breaker.

Next you would have to get the correct cable for the circuit. This means that you would have to look for a cable that can carry 21 amps. To safley carry 21 amps, ypo must use #10 AWG cable. You may use either a 25 mp breaker or a 30 amp breaker for this circuit.

Now, as to how you would do this, that's a different story.

If you already have a spare 15 amp circuit, then you would need to replace the 15 amp breaker with a 25 amp breaker. Then you would need to replace the 14 AWG cable from the breaker to the where you want the heater to be installed with 10 AWG.

Under no circumstances can you leave a 14 AWG cable (listed for 15 amps) in a 21 amp circuit. It is a very real fire hazard!!!

Please take a moment and verify the circuit requirements and get back to us. One other item, it is my very strong suggestion that you file for an electrical permit and then have the work inspected to make sure that it is up code level for you area.

As an alternate plan, may I suggest that you contact several local "Licensed" electricians and have them bid on the job. Working on the main panel can get you very dead if your have no experience working on electrical circuits.

P.S. As to the stove's 30 amp circuit. According to the NEC code, this is an independent circuit and as such, you cannot connect any other electrical device to it.