Hi , wife and I live in her mothers house now, it is a two wire ungrounded system throughout. She had someone come in and wire it with grounds, not everything had grounds but half of it did after he was done rewiring it, but the city inspector came through to look at it and said it was a fire hazard to have grounded circuits in a ungrounded system and told her to put it back to two wire ungrounded system where it was safe to use again. Everything in the house is ungrounded including the washer dryer combo. I understand I know I can replace the two prong plugs with modern grounded type so long as I don't use the ground terminal on it, I would love to rewire it with modern wiring and get rid of the asbestos insulated wires, clean up the look of it at the same time. I understand that I can do this , again as long as I don't use the ground wire in the cable. He said its our option to replace it with grounded circuits as long we changed out the 100 amp service box with a grounded service box. Anyone have any thoughts on two wire ungrounded systems, any information would be greatly appreciated. At the same time I'm reading and understanding better why the city inspector said it was okay to use the system the way it is. I still don't understand why it would be a fire hazard to ground the circuits to the box if it has a ground wire coming from the service line outside. Then again as I think about
It, if I I had mixed grounded and ungrounded circuits , it would cause some circuits to be hot that normally wouldn't be hot if there was a short circuit. Maybe if I grounded every circuit iin the house it would be okay, but don't want to cause any unneeded fires , just any information would be appreciated. Maybe someone with the same type wiring two wire ungrounded system has some insight.

I don't understand the inspector about "said it was a fire hazard to have grounded circuits in a ungrounded system ". Are you sure the word "circuits" was used, or was the word "outlets" used?

If a circuit that uses 3 wire outlets are an extension to an ungrounded circuit, then that is not good, gives the false impression the circuit and outlets are grounded when it is not.

Is there a problem with the grounding of the panel?

An existing 2 wire circuit can remain with 2 wire outlets. Consider that most devices in a home only has a 2 wire plug, such as lamps, clocks, TV, stereo, kitchen counter appliances. The large appliances, such as washers, refrigerators, etc use 3 wire.

Any kitchen, bathroom, garage, basement, and outdoor outlets must have GFI protection, whether 2 or 3 wire outlets.

Any other circuit or outlet in the home that is 2 wire but has a 3 wire device can use a GFI outlet or a GFI breaker to protect it, this means you can install a 3 wire outlet, have no grounded wire connected to the green screw, but must label any ungrounded 3 wire outlet with a label that comes with GFI devices, " NO Equipment Ground".

If you replace 2 wire outlets on a 2 wire circuit to 3 wire outlets, you can run a green wire from the green screw to the systems grounding electrode at the point the service is connected to the grounding electrode or connect to any location of the grounding electrode conductor.

You cannot just connect to any water pipe at any location. There are specific locations you may use to connect a ground wire.

I am using the actual technical wording, each which has specific meaning and context. Do not assume anything by the words I use, as you may not understand and make some assumptions. If there is any question, ask.

You may be best having an electrician come in and inspect the service to be sure the service is grounded properly, identify the grounding electrode system, and then perhaps once you are clear about where it is permissible to ground in your situation, then perhaps you can do the replacing outlets and grounding of them.

Or you can simply replace all the breakers for outlet circuits to GFI breakers, but this gets expensive since these breakers cost about $30.00 each. OR you can replace the first outlet in an outlet circuit to protect the entire downstream circuit and outlets.

I do need to say that this can be a confusing topic, and many people ( and unfortunately, some electricians and inspectors are confused also) think they understand , and think it is a simple fix. You may not understand and think you do, just be aware that there is a bit if specific detail unique to each building.

This can be difficult to explain since there are so many variables, so if you can provide some pictures,they would be helpful to explain what can be dome in your situation.