switching from isolated ground receptacle

Hifitime,

Actually it does makes sense. Table 210.21(B)(2) Maximum Cord-and-Plug-Connected Load to Receptacle, says the maximum cord-and-plug continuous load that can be connected to a 15 amp receptacle is 12 amps. For a 20 amp receptacle the max is 16 amps. UL / CSA requires manufactures to size the cord and plug accordingly for the load of their appliance or equipment.

Example, if the continuous load of an appliance or equipment is 12 amps or less then the manufacture uses a 5-15P 15 amp plug. If the continuous load is greater than 12 amps the manufacture must use a 5-20P 20 amp plug.
That is the reason consumer vacuum cleaners only have a so called 12 amp motor, max. Most house hold convenience receptacles are 15 amp (and more than likely #14awg wire, 15 amp branch circuit) so the manufacture has to use a 15 amp plug, that is if he wants to sell any vacuum cleaners. He has to make sure the total continuous load of his vacuum cleaner does not exceed 12 amps... Pretty much the same for power amps...... Maybe a few exceptions.....

As for the difference between a 15 amp and 20 amp receptacle, the only difference is the face plate. A 5-15P plug will fit a 5-15R or 5-20R amp recept. A 5-20P plug will only fit a 5-20R amp recept.
The guts inside a 15 amp recept are the same as a 20 amp recept.
Jim

Maybe,I need to stay at one of those Holiday Inn's,and bring a new NEC code book with me,plus a big bottle of aspirin.♫

Also,who's table 210.21(B)(2)for?The consumer that looks at the power consumption of the item they're plugging in? I have about 125v nominal.At 20 amps that's 2500 watts on a duplex they say is good for 12 amps or 1440 watts at 120v.They drive me crazy.

Jea48,Am I backwards,or them?Two heaters or other plugged into
that one 15 amp duplex on a 20 amp breaker.Sizzle,glow,and worse.

My 2005 is outdated.I have it in the computer.Time flies.I'm not going to buy a new one though.Table 210.21(B)(3)sounds like a 15 amp receptacle is ok for 20 amps. Sounds like a 15 amp duplex could overheat on a 20 amp circuit without tripping the breaker.I would think a 20 amp receptacle on a 15 amp breaker with 14 or 12 gauge wire would be safer.Consumers don't know what they're plugging in,so you have to rely on the breaker.I'm not a electrician,and I didn't stay at a Holiday Inn Express either!

They need to revise or clarify article 210 in the NEC in my opinion.
12-06-09: Hifitime

Hifitime,
which section?
Article 210 of NEC 2008 has many new changes....

Just one example, NEC pretty much made miltiwire branch circuits a thing of the past.

210.4 (B) Disconnecting Means. Each multiwire branch circuit shall be provided with a means that will simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates.

No changes regarding Table 210.21(B)(3) Receptacle Ratings for Various Size Circuits.
or
Table 210.21(B)(2) Maximum Cord-and-Plug-Connected Load to Receptacle.

Jim

They need to revise or clarify article 210 in the NEC in my opinion.

Viiu,

No problem at all with changing out the recept.

If you are going to install a 20 amp recept I should point out that technically, per NEC code, a 20 amp recept cannot be installed on a 15 amp branch circuit....
If that is your intent the electrician may make you aware of the fact. Just change the 20 amp recept to a 15 amp in the event you sell and move from the house.

Thanks for your answers. The outlet was installed in the early 90's and I wanted to be sure it was safe to switch to a grounded receptacle. I will have an electrician review.

Viiu,

14/3 wire.... NM-B cable, Romex example of? Not sure why you spent the extra money for an isolated grounding type receptacle in the first place.
In your case the isolated ground contact of the receptacle works the same as a regular grounding type receptacle. No isolation was needed.

It's on a dedicated circuit. To be more specific, do I need to pull a 14/2 wire to replace the 14/3 wire?

I assume, hope, the safety equipment grounding conductor was terminated on the ground bar in the electrical panel the branch circuit is fed from. If this is the case you need not do anything, just change out the receptacle.

I should point out though if an electrician installed the branch circuit wiring and the isolated grounding type receptacle and used a metal rough-in box for the recept he should of also connected the safety equipment grounding conductor, wire, to the metal box.....
If a plastic box was used everything is code compliant, but in this case by code you must use a non conductive recept cover plate.....

On an isolated grounding type recept the ground contact of the recept is not connected to the metal supporting back strap of the recept. By code the strap must also be connected to a safety equipment ground wire. (The strap of the recept is connected to the metal box by support screws which is connected to an additional safety equipment grounding conductor.)
Jim

No, the isolated ground duplex receptacle is internally configured to isolate the ground. Just attach the white & black wires to the correct sides and put the bare or green wire to the ground post of the outlet.