How safe is the old knob and tube wiring?
Knob and tube is the original wiring used in not only homes but theaters and other things back in the late 1800's and early 1900's. It is safe if in good shape and it is separated from hot to neutral so it cannot short out like romex wiring. It does not have a ground system (there was no grounds back then in this type). The adapters you are talking about are not actually grounding anything that needs to be grounded if they are just plugged in to a two prong outlet. There are no ground wires in knob and tube even if it is a metal box which it is. (that is what they used then). Many insurance companies will ask for an inspection of the house wiring if they do know it is knob and tube wiring. It must be on a 15 amp breaker and cannot have kitchen wiring on it, laundry receptacles on it, a furnace on it. any heavy appliances otherwise. They may ask for it to be replaced through out the attics, basements etc. where it is visible This can be a rea tough job and messy as well. I would at some time try to get you some estimates to have a contractor come out and look at it for you and see what they recommend, insurance companies may frown on it but they know it has lasted for over 100 years in many homes and has done its job. So many homes it seems have electrical fires what many people do not know that an extension cord is dangerous if used for long term and yes this is an electrical fire, not necessarily the house wiring but still an electrical fire by insurance reasons and fire Marshall's will tell you the same thing. People who use 100 watt or larger light bulbs in 60 watt rated sockets have fires and it too is an electrical fire, as well as portable heaters etc.. Is it safe, Maybe ? but it should be checked to make sure and it has to be on the proper size fuse or breaker. and nothing that requires a ground that could cause a shock or personal injury is not on it as well.
Why does my circuit breaker keep tripping?
You're overloading your circuit so it trips. Don't look at the wattage on the units; check the amps on the unit. If you're running both heaters at the same time, you will trip the breaker. Changing to a 20Amp switch is not necessarily a safe option either. True it might allow you to run both heaters at the same time, but if you overload the master, or overload the wiring on the individual circuit, then you're running the risk of burning down your home! You need to have a licensed electrician come in and review the situation and tell you what's the safest solution. cw
Is it ever worth it to rewire electric wiring in a 50-year-old house?
Define “worth it.” Actually, first let’s define “rewire.” Romex and copper conductors have not changed much in 50 years, so assuming the house does not have any small gauge aluminum, the cabling should be fine. Most of the small devices (switches, receptacles and circuit breakers) can easily be replaced and probably should be as builders generally use the least expensive commodity grade devices, and they do wear out.The incoming service is a different story. IMO any house of 2, 3 or more bedrooms now needs a 200A minimum service. If you are under that, it then becomes a question of what your goals are for the house. If you are watching pennies while looking to sell for a profit, then price it out and see if it fits into your plan. A 100A service is acceptable to most buyers and shouldn’t cost you a sale. If you are planning to stay in the house, maybe remodel or expand, a small service will become an issue.An integral part of the service discussion is the panel and breakers. Even standard breakers have improved significantly in 50 years, but more important are the advances in ground fault and arc fault interruption. The most recent electric code requires arc fault protection in almost every room, and if you do any significant updating under permit you will be required to upgrade. There are also increased requirements for dedicated circuits and ground fault protection, so you may need to meet those standards as well.So, back to “worth it.” Upgrading will cost you money, but if you go whole hog—AFI and GFI breakers, new devices, additional circuits—you will have astronomically increased the electric and fire safety level for your household. Upsize the service and panel, the price goes up again but then you’ll have all the power you need.
If I rewire my house do I need to add outlets to bring it up to code?
You can pull an "Owner Builder" permit and do some/all of the work yourself. Finding an Electrical Contractor willing to do some of the work will be a bit tricky. Finding an Electrician willing to "moon light" the part you don't want to do shouldn't be too hard. Depending on your local Building Department you will most likely have to conform to at least some of the current Codes. The line may be drawn as a % of the work, a % of the cost to do what you want to do or by some other means. So, a call to you local Building Department is in order. Regardless of what the Building Department has to say, you will want to add receptacles/switches to make the system more "user friendly". Doing so won't add a lot to the cost. The difference in cost between a 150 and a 200 amp panel and main breaker isn't a lot either. A Master Electrician or Electrical Engineer will be a big help in determining how many additional circuits you will need and what/how to run power to the garage. The Building Department will likely require drawings for all this work anyhow. Money well spent I assure you. I agree with the statement that you won't be able to use any of the existing wire to pull in new wire. The tricky part of fishing wires up a wall is being able to drill through the bottom plate along the exterior walls without coming up through the floor or piercing the outside of the wall. Getting up the walls from existing switches will almost for sure require some holes in the walls. You will encounter cross members (Cats/Cripples) that will impede your efforts. This is where someone familiar with, and experienced at, getting past them will earn their money. I'm going to list some of the things you may be asked to do: Install a Main Breaker outside. Drive 2 ground rods Install 2 "dedicated" circuits in the kitchen for counter top receptacles. Install gfi and arc fault protection. Install inter connected Smoke Detectors. Install a sub panel at the garage. Install 1 or more exterior receptacles. Just to name the more common possibilities. My suggestion is to hire this out. If you get 5 (or more) estimates you will be able to disregard the LOWEST as well as the Highest bid. You might not be happy with the reason someone is Low bidder! Pick from the others by reputation.
Why are fuses and circuit breakers used in household circuit?
The primary objective is fire prevention. Secondary objectives include selective protection (isolation of problem circuits while retaining service to the rest of the house) and to provide a means of disabling circuits for maintenance and repair. Fuses and circuit breakers generally DO NOT provide human shock protection. However, it is possible to purchase special circuit breakers with "ground fault circuit interruption" capability that may prevent shock.
Can I use a TL 25 AMP Fuse instead of a TL 20 AMP Fuse?
Recently I bought a 8000 BTU Air Condition to be put in my room and the current 15600 BTU AC to be put in my Living room for the whole hallway and living room. After reading the curcuit I realized both the Living room and my room share the same curcuit and I'm worried it will just always melt the fuse making them unable to be used. I was wondering if I can use a 25 AMP Fuse instead of the 20 AMP Fuse that it has standard The 15600 A/C says 12 AMPs i'm assuming the new 8000 BTU A/C is somewhere between 6-8 AMPS.
Do you need a permit to upgrade knob and tube electrical service in PA?
My dad passed away last year and left my sister and I his rental property in PA. It's a 3 BR, 2 Bath Twin about 1500 sq. ft built in 1929 and still has the original knob and tube electrical service. The longtime tenant complained about blowing through fuses in the summers, and I was looking to have it updated. I have heard that you can just have a certified electrician put a breaker box in and run new wire to the major appliances and leave the knob and tube in place, thus taking the load off the old wires but not having to rewire the whole house. Is this legal and if so, do you need a permit to have it done in PA? If you get a permit, is it likely they will make you rewire the entire house? My goal is to not do anything illegal, but update the service without causing too much hassle for the longtime tenant and not busting my bank account, if possible. I understand it wont be cheap and I'm not necessarily looking for the cheapest option, but not the most expensive either. If anyone knows what options I may have, I would appreciate it. Thanks in advance! Oh and if anyone has a rough idea on what the options may cost, that would help alot too. I know it depends on alot, but am I looking at $1000, 5K, 10K+?