Individual Water Heater

[Anwar Pasha]

Does NEC code allow to install more than one water heater on the same circuit? Where can I find about it in NEC!

 

[iwire]

Does NEC code allow to install more than one water heater on the same circuit? Where can I find about it in NEC!

More information is needed but in general you could not.

What are the unit ratings and types?

 

[Anwar Pasha]

These are normal domestic water heaters (portable ones) of 1200 watts, 220v single phase. I know that generally they are not permitted, but is their any NEC code pertaining it!

 

[iwire]

I know that generally they are not permitted, but is their any NEC code pertaining it!

I could not tell you one with the limited information you gave!

If I where you I would start with 422.11!

 

[Dennis Alwon]

If these are portable then 210.23(A)(1) seems to allow this install.

210.23(A)(1) Cord-and-Plug-Connected Equipment Not Fastened in Place. The rating of any one cord-and-plug-connected utilization equipment not fastened in place shall not exceed 80 percent of the branch-circuit ampere rating.

 

[Dennis Alwon]

Standard water heaters around here are 4500 watts and not portable.

 

[iwire]

Dennis, I think we are both right.

If you try to put two waters heaters on the same circuit you will run afoul of one section or the other.

 

[iwire]

These are normal domestic water heaters (portable ones) of 1200 watts, 220v single phase. I know that generally they are not permitted, but is their any NEC code pertaining it!

I think we have a failure to communicate.

Are these heaters for tea or something?

 

[Cavie]

How is a water heater "not fastened in place???" How many gals is concidered "Portable?"

 

[Mgraw]

Are these the point of use type with a cord and plug.

 

[Anwar Pasha]

I am sorry for misscommunication, its a storage type water heater. I went through article 422 but still the doubt whether two or more storage water heater can be feeded from a single circuit.

 

[augie47]

In all probability 422.11(E) is going to prevent such an install.

 

[Cavie]

I am sorry for misscommunication, its a storage type water heater. I went through article 422 but still the doubt whether two or more storage water heater can be feeded from a single circuit.

Something for you to think about. IF you were to install more than one per circuit, How would you protect each one individually and the circuit as a whole should they both come on at the same time????

 

[Dennis Alwon]

I still see nothing in 422.11 that prevents two heaters from the same circuit. 422.10 states

422.10(B) Circuits Supplying Two or More Loads. For branch circuits supplying appliance and other loads, the rating shall be determined in accordance with 210.23.

To follow thru I see nothing in 210.23 that disallows it. 422.10 appears to give the permission if you comply with 210.23

210.23 Permissible Loads.
In no case shall the load exceed the branch-circuit ampere rating. An individual branch circuit shall be permitted to supply any load for which it is rated. A branch circuit supplying two or more outlets or receptacles shall supply only the loads specified according to its size as specified in 210.23(A) through (D) and as summarized in 210.24 and Table 210.24.
(A) 15- and 20-Ampere Branch Circuits. A 15- or 20-ampere branch circuit shall be permitted to supply lighting units or other utilization equipment, or a combination of both, and shall comply with 210.23(A)(1) and (A)(2).
Exception: The small-appliance branch circuits, laundry branch circuits, and bathroom branch circuits required in a dwelling unit(s) by 210.11(C)(1), (C)(2), and (C)(3) shall supply only the receptacle outlets specified in that section.
(1) Cord-and-Plug-Connected Equipment Not Fastened in Place. The rating of any one cord-and-plug-connected utilization equipment not fastened in place shall not exceed 80 percent of the branch-circuit ampere rating.
(2) Utilization Equipment Fastened in Place. The total rating of utilization equipment fastened in place, other than luminaires, shall not exceed 50 percent of the branch-circuit ampere rating where lighting units, cord-and-plug-connected utilization equipment not fastened in place, or both, are also supplied.

 

[Dennis Alwon]

In all probability 422.11(E) is going to prevent such an install.

That is for a single appliance so how does that apply?

 

[iwire]

That is for a single appliance so how does that apply?

It applies to each appliance, you cannot decide to run a 100 amp circuit to supply ten - 9 amp appliances.

 

[Volta]

In all probability 422.11(E) is going to prevent such an install.

First place I thought to check too. But that is for circuits supplying a single appliance.

I think that two of these 5 amp appliances plus 25% will fit on a 15 or 20 amp circuit.

 

[cadpoint]

If this has to do with the assisted living center, I'm surprised that the ME hasn't a design for a system wide distribution piping off a single Massive H2O heater.

 

[Dennis Alwon]

It applies to each appliance, you cannot decide to run a 100 amp circuit to supply ten - 9 amp appliances.

The sentence states--If the branch circuit supplies a single non?motor-operated appliance, the rating of overcurrent protection shall comply with the following:

Now how does that apply to each one. The branch circuit supplies more than a single appliance.

I never said you could run a 100 amp circuit either.

 

[iwire]

Now how does that apply to each one. The branch circuit supplies more than a single appliance.

It does not, you are right and I was wrong.

I never said you could run a 100 amp circuit either.

It was an example.