Questions

jjdogg

2 quetions. one what do i tell my customers about why they need to have a range and dryer receptacles changed to four wire?
2. Why do they need arc faults?

mdshunk

If it exists, and nothing's being changed, it may remain. If you're changing anything related to that circuit, you need 4 wire to be in compliance with current codes. The old 3-wire setup used two hots and a neutral. The appliance is ungrounded. They do have a neutral to chassis jumper installed in the appliances that are 3-wire connected for a "poor man's ground". If the neutral path ever develops resistance or opens, the chassis of the appliance will be energized. The danger there is obvious.
If it exists, it may remain. Any new 120 volt stuff in a sleeping room must be arc fault protected, in accordance with the current code. There is no mandate to change anything that exists. Why? I dunno, other than the fact that the code requires it. It's supposed to be safer. I have my doubts with the current generation of parallel arc fault breakers. The combination type of arc fault breakers due out in early 2008 will be much safer, in my opinion. Until then, I think that the reason is mostly to satisfy code and make money for the breaker manufacturers.

Eric K

MDSHUNK,

When you say arc faults what do you mean by that, I'm not too up to date on my electric (Exp./code wise). Could you explain what that means so can take a mental note on it

erikthered

A arc fault circut in a nut shell knows your getting stray curent before you even fell it. If a child was to put a paper clip in the outlet the arc faultwould trip before the child was shocked

Eric K

Is it like a GFCI breaker? Same concept?

mdshunk

Sure, arc faults (or AFCI's) are Arc Fault Circuit Interruptors. They are a special type of breaker required since the beginning of 2005 for everything in a sleeping room of a dwelling. The actual code text reads as thus:

210.12 Arc-Fault Circuit-Interrupter Protection.
(A) Definition. An arc-fault interrupter is a device intended
to provide protection from the effects of arc faults
by recognizing characteristics unique to arcing and by functioning
to de-energize the circuit when an arc fault is detected.
(B) Dwelling Unit Bedrooms. All 120-volt, single-phase,
15- and 20-ampere branch circuits supplying outlets installed
in dwelling unit bedrooms shall be protected by a
listed arc-fault circuit interrupter, installed
to provide protection of the branch circuit.
Exception No. 1: The location of the arc-fault circuit interrupter
shall be permitted to be at other than the origination
of the branch circuit in compliance with (a) and (b)
(a) The arc-fault circuit interrupter installed within
1.8 m (6 ft) of the branch circuit overcurrent device as
measured along the branch circuit conductors.
(b) The circuit conductors between the branch circuit
overcurrent device and the arc-fault circuit interrupter
shall be installed in a metal raceway or a cable with a
metallic sheath. [ROP 2–134a]
Exception No. 2: AFCI protection shall not be required for
an individual branch circuit supplying a dedicated outlet
for life support equipment in dwelling unit bedrooms. Such
receptacles shall be marked “Life Support Equipment
Only.”
FPN: For information on types of arc-fault circuit interrupters,
see UL 1699-1999, Standard for Arc-Fault Circuit
Interrupters.

Notice that this applies to all 120 volt, 15 and 20 amp outlets in bedrooms. An outlet is not just a receptacle. The code defines an outlet as:

Outlet. A point on the wiring system at which current is
taken to supply utilization equipment.

This means that all 120 volt, 15 and 20 amp receptacles, lights, smoke detectors, etc. in a bedroom need AFCI protection. The exception is for life support stuff like an oxygen generator or IV pump. There are commercially available receptacle covers that are embossed “Life Support Equipment
Only.” You don't need to AFCI, for instance, a 220 volt air conditioner receptacle, because it isn't 120 volt.

erikthered

Same thing

mdshunk

An AFCI is different than a GFCI, but an AFCI does offer some level of GFCI protection. Confused yet?

A GFCI will only detect faults between either the hot and the ground, or the neutral and the ground. A GFCI will trip at 6 milliamps of imbalance to provide protection of people.

An AFCI will also detect the same faults as a GFCI, but will trip at 30 milliamps to provide protection of equipment only. This trip level is way too high to ever protect people the way a GFCI will. Also, unlike a GFCI, an AFCI contains additional electronics that detect certain disturbances in the sinusoidal waveform of the AC power, unique to arcing and sparking type faults. As a result, AFCI's, unlike GFCI's, will trip under arcing circumstances too.

Eric K

So, if I were to change just outlets out in a bedroom, I would also need to change the breaker to that room to a AFCI breaker to keep up with code? If so, just one more thing to get paid for

mdshunk

Like if you were swapping out ivory devices for white? or standard for decora style? I doubt that any jurisdiction would enforce you to change to an AFCI at that time, but you could try to upsell it.

You may run into trouble...
The typical AFCI will protect a single circuit, that is a single 14-2 or 12-2 cable. Before AFCI's came on the scene, it was normal for bedroom circuits to leave the panel as a multiwire circuit. Two circuits on one 14-3 or 12-3 cable to serve several areas. If this bedroom you intend to AFCI protect is served by a circuit that is in a 14-3 or 12-3 cable, you need to use a double pole AFCI breaker. These are darned expensive, and Cutler Hammer is the only manufacturer making them at the present time as far as I am aware. A normal AFCI breaker would run around 40 bucks. The last double pole AFCI that I bought was $154 dollars at the wholesale house. Do your homework by looking in the panel before you jump at upselling AFCI's where they otherwise wouldn't be legally required. You can (and I have) upsold people on AFCI protecting every 120 volt circuit in the entire panel. This is an easy $1000 profit for an electrician for not too much work.

Eric K

Why do they not just make it code to just have all breakers GFCI'd to protect the whole house from human shock, Also would doing this "child proof" the outlets?

CGofMP

part of the reason not to GFCI everything is because things like refrigerators and such can play hell with GFCIs. If you are on vacation and your fridge pops the GFCI you get to come home to a lot of rotten food, a flood in your kitchen (maybe) and a lot of cursing.

__________________
Memorable Places - My little home on the web
Member of the White Knights Of Contractor Talk

mdshunk

That day's coming, mark my word. In Europe, they do have available GFCI main breakers in the panels to protect everything. They call them something different.

mdshunk

RIGHT!

Make this mental note... if you're on a service call for a faulty freezer receptacle, don't open the freezer no matter how curious you are. The smell of 200 pounds of rotten deer meat and several dozen rancid trout will stick with you for quite some time.

Eric K

Thanks for all the info.

Speedy Petey

GFI's do not protect from shock, they protect from electrocution.

__________________

MinConst

I take it there are no arc fault products available at the point of use (duplex style) like GFCIs?

__________________
Paul
Minichillo's Construction
Website
I will never leave you hanging!

jbfan

Not yet, but I am sure they are coming!

__________________
We are the people (our parents warned us about) (Jimmy Buffett)

mdshunk

I wish they'd hurry up, so that I can start running multiwire bedroom circuits again. I plan to feature the device style AFCI on the same plate with each bedroom's light switch. Part of the trouble, I'm told, is that the breaker manufacturers don't manufacture devices, and there are some technology licensing issues.