Replace all Wiring that was Stolen any great suggestion???????????

[Chad Schloss]

i beg to differ on the hair dryer. ever taken one apart? i have. many. they all had over current protection. iron? yep same there too. fan? not sure. window air cond? sure do. the ones i have taken apart. coffee maker? yep. lamp? nope. i think all things, including extention cords, should be fused. even christmas lights are fused.

here is a type of OCP in a hair dryer:

http://www.busytrade.com/selling-lea...ting-Cord.html

what are devices tested for? how does one get a UL rating? that is one of the certifications you should be aware of when looking at appliances. not so much in the US, because most everything you can buy has passed some sort of testing that they or another company has done to make sure you don't burn your house down if you leave your coffee pot on when you leave your house. thermal fuses protect the device from causing a fire. like i said, most everything has over current protection.

[DonL]

I have yet to see an appliance that had overcurrent device installed in it such as TV radio ect......
Have you got a wiring digram that shows this?

I sure do have schematics and ALL TVs have protection. On the Low and High Voltage Supplies.

Radios have protection also. Some are fuse links built into transformers, just like Doorbell and most appliance transformers have.

Most all DC operated TVs and Radios have reverse polarity protection also.

They are not always made to be user replaceable, But they can be replaced.

Most everything that has UL Approval will have internal protection of some kind.

Even CFL bulbs have a fuse. The only way that I know is because I took one apart that blew to play with it and see what went bad.

Water heaters and coffee pots have a breaker or fuse link built in. Compressors have auto reset over current devices.

Chances are if a appliance quits working, it is because of a fuse that is blown in the device. Normally for some good reason, But vary rarely will it blow a 15 amp panel breaker.

A heating element operating on 240VAC may be a exception and may trip a breaker if it shorts to Neutral or Ground.


A Fuse may not protect against stupid, because you can not fix Stupid with any size wire, fuse or breaker.

[DonL]

Your tv set may have overcurrent protection. Your hair dryer, iron, toaster, fan, window air conditioner, any lamp, etc. DO NOT.

Most anything that has a heating element will have a Thermal Fuse that is also current limiting.
No reset they just open do to improper air flow or over current.

A window air conditioner should have a compressor current limit for excessive head pressure or Rotor Lock and a internal Fan Motor thermal/current protector, both that are normally auto resetting.

The only fuse on a lamp is the bulb itself, or the lamp cord.

[Homeownerinburb]

"There is no advantage in installing the 20 amp circuits but it does cause dangers to lurk. "

why then are we required to wire not one, but two small appliance branches for kitchen appliances at 20a each for appliances that require 15a? how about the requirement for bathrooms to have a separate 20a GFCI circuit dedicated to just the bathroom, for a 1500w hairdryer that can run on 15a?

Because in both those circumstances relatively high wattage demand is expected, and it is wise to design electrical circuits to be somewhat heavier than their expected steady demand. This accounts for the occasional dodgy wire joint and the occasional insulation abrasion, to say nothing of the occasional excess torque in pulling a wire that might weaken a conductor.

It is foolishness to arrange a 15 amp circuit that is seeing 1700 watts on a steady basis. In a general lighting circuit one might say, wait, so let's use a 20 amp circuit. Better practice is to install one more 15 amp circuit than is absolutely required in the 3 watt per sq ft standard. It is still cheaper, nearly all the time, than working with 12ga.

Especially considering the time the electrician squanders wrestling with the heavier wire. 14 gauge, either in NM, MC, or pulled into conduit, is just always going to be quicker to work with and less demanding of an assistant to guide the wire or push it into the conduit as it is being pulled.

In a bathroom, both a hair dryer and a curling iron can be going at once. At least if my wife has anything to say about it. The 2400 watts get tested.

In the kitchen, it is permitted to plug the refrigerator into one of the small appliance circuits. If that circuit were a 15amp job, many common counter appliances joined with the refrigerator would be enough to trip the breaker. Me? I never let the customer cheap out like that. I always insist on a dedicated 15 amp circuit for their refrigerator. It does not take much persuasion to get the point across. If you have ever opened a refrigerator that has lacked power for several days due to a power loss of any kind, you would be an easy sell. Oh, and the receptacle for a circuit that has only one dedicated use, say a refrigerator or a microwave, is supposed to be a single outlet, not a duplex. The dedicated 20 amp circuit for a laundry room, of course, should be a duplex, as both the washer and dryer (gas) can be carried by a single 20 amp circuit.

I just cannot see any upside to using 12 ga wire where 14 ga will do. I just don't want to be stuffing that thick stuff into boxes. Especially as I find myself designing fairly complex lighting control and perhaps having three dimmers in one box. It just is not worth it, and it costs more.

And it is safer to protect the smaller items around the house with a 15 amp breaker.

[jwelectric]

Can someone please explain to me with all this overcurrent protection in all these appliances just how one could start a fire?

I do believe that some here are thinking that thermal protection is overcurrent protection. How sad.

[DonL]

Can someone please explain to me with all this overcurrent protection in all these appliances just how one could start a fire?

I do believe that some here are thinking that thermal protection is overcurrent protection. How sad.

True for the most part. Depends on the type used.

http://en.wikipedia.org/wiki/Thermal_cutoff


They do come in different current ratings.

http://www.us-electronics.com/files/...utofffuses.pdf


Normally they are for Fire protection. But excessive over current will heat them up and they will open.

Most Kitchen Appliances catch fire from over cooking something. Gas and Electric.

[jwelectric]

Don, one good point that can be made on thermal protection and overcurrent is the red reset button on a water heater. That button is in place to keep the water heater from overheating and exploding. It will not open no matter how much current flows through it. It is not current sensitive but thermal sensitive. Your links are to current sensitive overcurrent devices not something like the thermal device on a water heater which is not current sensitive.
A thermal fuse is current sensitive as that is what it is designed to be but there are a lot of thermal sensitive components that are not current sensitive and will not open no matter the amount of current that flows through them.


The overload installed on a garbage disposal is a little different. Once the motor reaches a certain temperature the thermal overload will open to protect the motor from fire. The rules for overload protection of motors can be found in Article 430 of the NEC. This device will be set somewhere between 125% and 156% of the full load amps of the motor. These devices are current sensitive.

The reset on a water heater is not designed to open at any percent of the current rating of the water heater but is set to open when the exterior of the tank reaches a certain temperature.

Current limiting devices found on items such as coffer makers and cooking appliances are not overcurrent devices. These devices are designed to limit a certain amount of time in which current is allowed to pass not to limit the amount of current that can flow during this intermit time.

A couple of years ago my microwave quit working. When the door was opened the light would come on but the microwave wouldn’t work. I call out the tech and he found a blown fuse and tried to replace it to no avail so we replaced the microwave.
The point is that although there was a fuse in the microwave that opened it did not stop current flow to the appliance completely.

Now comes a little understanding of just how overcurrent works. If the overcurrent device is on the inside of the appliance it will protect anything downstream of where it is installed but the conductors from the receptacle and that overcurrent device is protected by the branch circuit overcurrent device.

My contention is that a 20 amp circuit will allow at least 600 more amps to flow on the conductors between the receptacle and the internal overcurrent device in the appliance should the appliance have one. This would be on a continuous load. In the event of a fault this current could be as much as 6 times the rating of the overcurrent device so there would be as much as 40 amps difference between a 15 and 20 amp circuit. This 4800 watts can last for a very long time to wit the cords fails.
If this fault is between the receptacle and the overcurrent internal of the appliance the only protection is the branch circuit overcurrent device. If this device will let through six times its rated current for a period of 2 seconds and it is protected by a 20 amp overcurrent device then the supply cord can see as much as 14,400 watts of heat. This is more heat than my whole house heat in my air handler which is protected by a 60 amp breaker.

Unless one understands the trip curve of their overcurrent device then they will never understand what is being addressed in this discussion. Do a Google search of “trip curve” and see for yourself just how much current that can be on the supply cord from the receptacle and the appliance.

This is what I debate when someone makes the statement that a 20 amp general purpose circuit is better than a 15 amp circuit. In most cases the 20 amp circuits in our home are being observed while in use. The wife is standing right there when using a blow dryer or curling iron. I am in the kitchen when cooking. I will be returning to the pot when making coffee but the appliances plugged into my general purpose circuits are not being observed while I am at work or in bed asleep.
Last week was the first time I had saw the cords and receptacle that supplies my TVs in a long time. We did an upgrade of Direct TV and the tech had to access these receptacles. I also replaced the surge protectors as they didn’t look all that good, the cords that is.

This can and will be debated for many years to come but unless we have a full understanding of current flow the point will never be settled. The adage that more is better will always be in the forefront and will be hard to dispel. Liken it to medicine, I am in pain so the doctors gives me 4 ccs of morphine. More is better so I ask for 8 ccs and my breathing stops. I suppose more was better as I no longer feel pain.

[jwelectric]

While discussing this topic with others someone brought up a good point. Has anyone here ever cut through a live cable or cord? Did it burn a hole in your cutters?

This same heat energy is present in that 16 or 18 gauge cord supplying the appliances in your homes. Is it safe to protect them at 20 amps when all that is required is a 15 amp overcurrent device?

[ballvalve]

I have 2 pair of dikes that these live cuts made a pefect wire stripper out of their jaws. My favorite tools.

I would add that some of these internal safety devices are made cheaply and are a part of designed obsolescence. I got 5 more years out of a 1500 watt electric hot plate that I use outside in the garden by cutting the little junker out.

[Chad Schloss]

While discussing this topic with others someone brought up a good point. Has anyone here ever cut through a live cable or cord? Did it burn a hole in your cutters?

This same heat energy is present in that 16 or 18 gauge cord supplying the appliances in your homes. Is it safe to protect them at 20 amps when all that is required is a 15 amp overcurrent device?

i guess we need to go to 5 and 7.5 a breakers now to protect what should have been protected in the first place...

[Chad Schloss]

"A couple of years ago my microwave quit working. When the door was opened the light would come on but the microwave wouldn’t work. I call out the tech and he found a blown fuse and tried to replace it to no avail so we replaced the microwave.
The point is that although there was a fuse in the microwave that opened it did not stop current flow to the appliance completely."

so what? you mean to tell me that you don't think that appliances have more than one fuse? look, i never said 20a/12 ga was better than 14ga/15a. i stated what i did, and i don't have to answer to you, or even the local AHJ. it is completely acceptable to wire receps with 12 ga wire. how come you never responded to any of my questions? you sure can dish out how more=bad, but no answers as to why code requires 20a in kitchen and bath for 1500w and less appliances...

[jwelectric]

. how come you never responded to any of my questions? ...

Maybe I am but you just aren't reading them

[Chad Schloss]

"In a bathroom, both a hair dryer and a curling iron can be going at once. At least if my wife has anything to say about it. The 2400 watts get tested."

you just proved my point. HOW do you know what those outlets will be used for in a living room? high power a/v equipment can draw a lot of current. so i should wire a dedicated circuit for the tv area? what if they rearrange the room? when then?

"In the kitchen, it is permitted to plug the refrigerator into one of the small appliance circuits."

must be where you are at. that won't fly here. dedicated circuit needed. 15a minimum

[Chad Schloss]

Maybe I am but you just aren't reading them

post #42 and 44 remanin unanswered.

[jwelectric]

high power a/v equipment can draw a lot of current. so i should wire a dedicated circuit for the tv area? what if they rearrange the room? when then?

I always did and should they decide to move it then a new circuit

"In the kitchen, it is permitted to plug the refrigerator into one of the small appliance circuits."

must be where you are at. that won't fly here. dedicated circuit needed. 15a minimum

This is a code compliant installation. It must be some sort of an amendment in your area