Water Heater disconnect

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sandsnow

sandsnow

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Southern California
Some inspectors are requiring disconnects for water heaters per section 309.0 in the Uniform Mechanical Code '97. That's what were on in CA. They do not allow use of the exception in NEC 422 to have it out of sight and lockable.

Anyone seen or heard of this?

I don't think that water heaters(other than boilers) are specifically covered in the Mech code

Thanks
 
Re: Water Heater disconnect

2-Pole switch, a 1-G to 4S extension ring and an industrial raised cover at the tank outlet box and you're done.
 
Re: Water Heater disconnect

I can see this issue from two perspectives. On one hand, providing a convienent means of disconnect at the equipment served or at least in sight of the equipment is a good way to make your customer and inspector feel you are willing to go the extra mile and not willing to take advantage of exceptions.

On the other hand, if someone begins work on an appliance or other equipment before placing that equipment in a safe working condition, then the result is in God's hands. I'm not in favor of code or any other legislation that mandates required protection of those who don't protect themselves when possible.
 
Re: Water Heater disconnect

On the other hand, if someone begins work on an appliance or other equipment before placing that equipment in a safe working condition, then the result is in God's hands.

Bryan a breaker lock is supplied to ensure a piece of equiptment is safe to work on and if the person declines to use the safe guard.At that point they have decided to forego their own safety.
No different than not using a parking brake while changing a flat tire.Stupid is as stupid does ;)
 
Re: Water Heater disconnect

The point of my question and I'm sorry if it wasn't clear was "do you consider a water heater as covered by the mechanical code?"
If it is, then section 309.0 requires a disconnecting meanss at the equipment and there are no exceptions here, like in the NEC.

Equipment regulated by this code requiring electrical connections of more than 50 volts shall have a positive means of disconnect adjacent to and in sight from the equipment being served. A 120 volt receptacle shall be located within 25 feet of the equipment for service and maintenance purposes. The receptacle need not be located on the same level as the equipment. Low voltage wiring of 50 volts or less within a structure shall be installed in a manner to prevent physical damage.

That is the section in the mechanical code. I always thought water heaters were regulated by the plumbing code. I can't find anything that directly regulates water heaters in the mechanical code. Boilers yes, water heaters, no.

If water heaters are regulated by the mechanical code, then we also need service recep's w/in 25 feet of the water heater.
 
Re: Water Heater disconnect

Originally posted by sandsnow: Equipment regulated by this code . . .
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I don't have a copy of the Mechanical Code handy. Is there a statement early in that book, similar to our 90.2, that establishes what is, and what is not, covered by the Mechanical Code?
 
Re: Water Heater disconnect

Yes there is charlie

Pupose: ...by regulating the design, construction, installation, quality of materials, location, operation, and maintenance or use of heating, ventilating, cooling, refrigeration, systems, incinerators and other miscellaneous heat-producing appliacnes within this jurisdiction.

Scope ....same list of items as in purpose

Chapter 10 Steam and Hot-water boilers specifically exempts potable water heaters 120 gals or less having a heat input of 200,00 Btu/h(58.62kW) or less used for hot-water supply at pressure of 160 pounds per square inch or less at a temperature not exceeding 210'F as regulated by the plumbing code.
So to me it's not covered. Sometimes people get stuck on things and it's hard to get unstuck. Either I'm stuck or the other person is stuck. One of us will become unstuck.

I din't want to delve to much into Mech Code details here since this is an electrical forum and many people can't follow along because they do not have a mech code book.

I was just wondering if electricians or inspectors have seen this section enforced or are enforcing it??
 
Re: Water Heater disconnect

Originally posted by sandsnow: . . . and other miscellaneous heat-producing appliances within this jurisdiction.
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I can't answer your question, being neither an electrician nor an inspector. But I can give you support for your point of view.

A water heater is not a "heat producing appliance." It is a "hot water producing appliance." It may sound like I am just playing with words, but I believe this is an important distinction. The purpose of the water heater is not to produce heat that can be carried by ducts to other rooms so that the rooms become warmer. "Heat" itself is not the product of the water heater. I conclude that a water heater is outside the scope of the Mechanical Code, as defined in the code section that you have quoted.
 
Re: Water Heater disconnect

and other miscellaneous heat-producing appliances within this jurisdiction.
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it produces heat, so do heat strips in an air handler. does it really matter what the medium used for transportation is?

if we use the idea that it creates heat and then water absorbs it then i would assume an air handler wouldnt qualify either since the heat strips create heat and the air absorbs it.

transfer of thermal energy is transfer of thermal energy be it earth wind fire air water jello shots, whatever.

<flame suit on>
 
Re: Water Heater disconnect

The difference as I see it is the end result of the heat produced.
In the air handler it's space conditioning
With the water heater it's hot water
 
Re: Water Heater disconnect

Originally posted by PlnOldRick:. . . does it really matter what the medium used for transportation is?
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It's the difference between "convection, radiation, and conduction," as compared to convection alone.

The air is heated and then moved to another room. That is "convection." Once the heated air is in the other room, it will transfer its heat (by both radiation and conduction) to the air and surfaces of the other room.

By contrast, the water is heated and moved to another room. That too is "convection." But once there, the intent is that the water retain its heat, and not transfer that heat by any means to the surrounding area. There will be heat loss, of course, but transfer of heat is not the design intent.
 
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