Old Romex

[tom baker]

A 2 wire receptacle can be replaced with a GFCI on a non grounded circuit. See 406.4(d)(3) IMO this is safer than a 3 wire grounded system.

 

[Jim W in Tampa]

A 2 wire receptacle can be replaced with a GFCI on a non grounded circuit. See 406.4(d)(3) IMO this is safer than a 3 wire grounded system.

Not always.You still could get shocked and if standing in water you might been better off with a real ground while holding that skill saw.

 

[stickboy1375]

Then why do we install GFI's Jim?

 

[Jim W in Tampa]

Then why do we install GFI's Jim?

To protect the user from shock on non grounded devices and ones where the ground went bad.GFCI do save lives but grounds are still needed on some equipment.If they where a cure all we would be back to using 2 wire receptacles and saving copper.

 

[iwire]

To protect the user from shock on non grounded devices and ones where the ground went bad.GFCI do save lives but grounds are still needed on some equipment.If they where a cure all we would be back to using 2 wire receptacles and saving copper.

I agree with Jim here, GFCIs do not prevent shocks.

GFCIs attempt to prevent lethal shocks by limiting the duration of the shock.

 

[iwire]

I am from Ma.

I thought you where.

Well we don't use Article 80.

The 2002 Massachusetts Electrical Code (527 CMR 12.00) of the Board of Fire Prevention Regulations shall be the 2002 National Electrical Code modified as follows:

Delete Article 80 and insert the following provisions ahead of the body of the Code:

That is from 2002 but 2005 is basically the same.

According to the instructor it is a violation of NEC 80.9(C) It reads in part Additions,alterations,installations or repairs shall not cause any existing buildings to become unsafe.

He should be telling the students about the MA 'rules'.

Rule 3. Additions or modifications to an existing installation shall be made in accordance with this Code without bringing the remaining part of the installation into compliance with the requirements of this Code. The installation shall not create a violation of this Code, nor shall it increase the magnitude of an existing violation.

I can not see how replacing fuses with the correct size breaker increases the magnitude of an existing violation if there even was an existing violation.

 

[racerdave3]

I agree with Jim here, GFCIs do not prevent shocks.

GFCIs attempt to prevent lethal shocks by limiting the duration of the shock.

Jim/Bob, I guess I question this somewhat. From what I have read through the years, a GFCI will trip at 4 miliamps (.004 amps). The current sensing coil in the unit monitors the current flow on the hot and the neutral of the circuit. The moment it senses the imbalance (a leakage potentially causing a shock) the device will trip on a ground fault condition. A properly functioning GFCI should trip so rapidly that not even a tingle will be felt. All this of course depends on proper monthly testing of the device to insure it's continued operation, which I'm sure every one of us here always do :roll: If the device does fail, then it is basically as effective as an old FPE circuit breaker.

 

[iwire]

I guess I question this somewhat. From what I have read through the years, a GFCI will trip at 4 miliamps (.004 amps).

Yes it will start to trip between 4 to 6 MA.

The current sensing coil in the unit monitors the current flow on the hot and the neutral of the circuit. The moment it senses the imbalance (a leakage potentially causing a shock) the device will trip on a ground fault condition.

Yes, The moment it senses the imbalance the device will start to trip on a ground fault condition.

A properly functioning GFCI should trip so rapidly that not even a tingle will be felt.

That is incorrect, you will feel a 120 volt shock at full available current until the device actually opens.

Have you ever seen a GFCI protected circuit shorted to ground?

The arc flash looks just like the arc flash on a circuit without GFCI protection.

Don't get me wrong, I like GFCIs, I regularly install them in areas they are not required.

 

[ptonsparky]

Jim/Bob, I guess I question this somewhat. From what I have read through the years, a GFCI will trip at 4 miliamps (.004 amps). The current sensing coil in the unit monitors the current flow on the hot and the neutral of the circuit. The moment it senses the imbalance (a leakage potentially causing a shock) the device will trip on a ground fault condition. A properly functioning GFCI should trip so rapidly that not even a tingle will be felt. All this of course depends on proper monthly testing of the device to insure it's continued operation, which I'm sure every one of us here always do :roll: If the device does fail, then it is basically as effective as an old FPE circuit breaker.

The GFCI did trip and no doubt saved his life but my brother says "It hurt like hell!"

 

[Jim W in Tampa]

The GFCI did trip and no doubt saved his life but my brother says "It hurt like hell!"

Most people have far too many things to do than check there gfci every month.Most never do.Stop and think what might happen if it fails on day #2 after the check and is next to the swiming pool that you use for that radio.They do fail and someone with a weak hart just might not be able to handle even 5 ma.

As to the OP ,insurance companies have the right to pick who they care to insure.Would you rather insure a 16 year old boy with a brand new license and a corvette or a 40 year old man with perfect driving record in a new ford ranger and with a high credit score? The rates will be higher for the kid but even at 3 times the premium that kid is a poor risk.Personally i would rather insure a home that was built atleast a year or 2 ago but under 10.Also would exspect that in areas that are strong code inforcers that the losses are lower.Who wired the house ? Here it likely was done atleast in part by a helper with perhaps a year or 2 of training.Many veryables set the price for insurance.