Space heaters

[noxx]

In my days of perfoming service calls, I cannot count the number of times I have found a circuit burned up by the load of a space heater. These 1500 watt monsters should by all means have a designated circuit, yet they are never marked with any warning concerning circuit overload. They are marketed simply as "bigger is better" and the average homeowner never thinks twice before running one all night and torching a 15 or 20 amp convenience circuit. As far as they are concerned it has a regular cord, it's fine to plug in anywhere.

I'd really like to see the NEC adress this, by requiring all appliances over X wattage to be clearly identified for use with a dedicated circuit only.

Just wanted to carp about that, it's easily one of the most common problems out there in residential work.

-Noxx

 

[goldstar]

Re: Space heaters

Noxx,

I agree with you. However, as long as the manufacturers are permitted to sell these heaters with a 15 amp attachment plug their sales will be up. If they are forced to sell them with a 20 amp plug their sales would drop severely. Then, of course, there will always be the homeowner who will make up an extension cord with a 20 amp female and a 15 amp male end and then buy the heater anyway figuring they "beat the system."

 

[iwire]

Re: Space heaters

Even if you could get a code article to require dedicated circuits for these loads would it happen?

Would the homeowner buy the space heater and then hire an electrician to install the dedicated circuit.

1500 watts at 120 is 12.5 amps, though if you look at the appliance I would bet it is rated 1500 watts at 125 volts which comes out to 12 amps.

2002 NEC

210.21 Outlet Devices.
Outlet devices shall have an ampere rating that is not less than the load to be served and shall comply with 210.21(A) and (B).

B) Receptacles.
(2) Total Cord-and-Plug-Connected Load. Where connected to a branch circuit supplying two or more receptacles or outlets, a receptacle shall not supply a total cord-and-plug-connected load in excess of the maximum specified in Table 210.21(B)(2).

Table 210.21(B)(2) shows up to 12 amps on a 15 amp outlet and circuit or 16 amps on a 20 amp outlet and circuit.

If the house is wired to the current code why would it be a safety issue for the code to further address?

 

[noxx]

Re: Space heaters

Bob your math and references are correct, my reasoning however is as follow -

To begin, 1500w was an arbitrary number, many space heaters exceed this. Given that a space heater consumes most, if not all, of the available load on a branch circuit, would not a safety concern be eliminated by removing the potential for other loads on that circuit? The problem is, outlets are not marked with a circuit number, so Joe Homeowner has no idea what receps share a circuit, aside from not having the slightest idea of how to calculate load. The average homeowners concept of overload is limited to whether or not the CB trips.

Ideally, a properly wired branch circuit should be able to support the indicated load, however, any load at or near max over any appreciable period of time -will- trash the connections slapped together by the average roper. Space heaters happen to be my chosen boogeyman for this common overload problem because they are really the only heavy-load, non-fixed, plug-connected appliance that is run for any length of time. Hair dryers are a bit ridiculous as well but are, thankfully, operating only briefly.

In many previous versions of the code, a proper installation, used properly, would have no faults. However, the uses, and abuses, practiced by average people have to be adressed, and have been the motivating factor in innumerable additions to the NEC. The problem that I see here, is that the owner does not grasp the amount of load a heater places on a circuit, hence my suggestion that they be more clearly marked for their intended use.

-Noxx

[ May 10, 2003, 09:55 AM: Message edited by: noxx ]

 

[don_resqcapt19]

Re: Space heaters

Noxx,
There is no way to know, when the house is being built, where the heater may be pluged in. Your idea would require all receptacles to be on there own 20 amp circuit. We don't need new rules to make the use of high wattage appliances safe, we just need better enforcement of the existing code rules.
Don

 

[bennie]

Re: Space heaters

Hopefully anyone who can afford separate circuits would not be using a portable heater.

The sad part, of this problem, is it becomes an ongoing hazard in low income areas.

The problem is mostly the natural degrading of connections and insulation.

Some of the breakdown may be detected with an AFCI, but most of the occupancies will never see one.

The rich will have them, and do not need them, the poor need them but will never see them.

 

[ronaldrc]

Re: Space heaters

Most of my service calls that pertain to half the lights and recpts. not working are usually
caused from this situation.

There is usually a receptacle burned very badly. And I would say 90 percent of the time this happens because there is a 120 volt window air conditioner or portable heater plugged into one of the outlets on this string.

I know it would be expensive to put everything that pulls a substantial load on a dedicated circuit but you can't put a price on a life although some businesses do.

I know if every installion was perfect and every connection was solid we wouldn?t have this problem but we live in the real world and its not perfect and no matter how hard you
try to do a perfect job you will still make mistakes.

It should be a requirement to have a air conditioner or portable heater on a dedicated
circuit.

Ronald

[ May 10, 2003, 12:50 PM: Message edited by: ronaldrc ]

 

[don_resqcapt19]

Re: Space heaters

Ron,

It should be a requirement to have a air conditioner or portable heater on a dedicated
circuit.

There is no way to know where these appliances are going to be used. The heater could be pulled into any receptacle in the house and the AC could be at almost any window.

I know it would be expensive to put everything that pulls a substantial load on a dedicated circuit but you can't put a price on a life although some businesses do.

Actually all businesses and governments look at the cost/benefit for products and safety rules. It is not possible, at any cost, to make everything 100% safe. The cost of compliance with a safety rule or use of a safer product is always balanced against the injuries or deaths prevented. Yes, often many can be saved at a small cost and it is done, other times the cost is so excessive for the benefit, that no action is taken.
Don

 

[bennie]

Re: Space heaters

These circuit failures will be increasing in days to come. The major expansion of domestic wiring was in the 1930,s. The life span of some equipment has been exceeded.

All electrical equipment and material will eventually fail. The only thing a person can do is plan to contain the effects of the failure.

These failures are a conspiracy among the 911 operators. Job security

 

[ronaldrc]

Re: Space heaters

Don

Like I said we don't live in a perfect world couldn't they require 20 amp. plugs?

Or the very least put a warning note on the equipment that states , This device can cause a fire in another part of your house that this device is not plugged into.

The average joes that purchase these heaters have no idea of the fire causing potential they present.

Most think as long as its not knocked over or the plug it is plugged into is not warm or hot everything is OK. they have no idea that maybe a recpt. is cherry red and ready to burst out in flames in other room because of this heater or ac unit.

I no the manufacturers will agree with you less just take no action at all, no we can't have a perfectly safe world.

If everyone felt the way you do we probably wouldn't have a GFIC or AFIC.

Ronald

 

[noxx]

Re: Space heaters

I know it's wildly impractical to try to build in enough dedicated circuits beforehand without knowing where the appliance will be used, I'd just like to see more thorough labeling on products that consume so much load. A little consumer awareness if you will.

However, come to think of it, a requirement for one identified, dedicated 20a circuit in every bedroom would cover it pretty well too.

-Noxx