Many insurance companies consider knob and tube wiring
unsafe (or at higher risk), due primarily
to its age. And, as many of you know,
mortgage companies require insurance before closing on a new home, thus, no
insurance = no mortgage = no house! Naturally, in those cases you need to
renovate the old wiring in accordance to the modern standarts.
When you upgrade old wiring or remodel your house,
you’ll have to meet the latest electrical codes.
When additional outlets are added, it could cause the fuses (or breakers) to blow. The unsuspecting homeowner then puts in 25 or 30 amp fuses to "solve" the problem. Allowing 25-30 amps to flow through these wires causes them to overheat, thus causing the insulation and copper wire to become brittle. Brittle wire has a higher risk of arching to something flammable.
Knob and tube wiring does not have a ground wire. A ground is necessary if you are plugging in appliances that have a third prong in the plug.
When you upgrade old wiring or remodel your house, you’ll have to meet the latest electrical codes. Here are some important code requirements, based on the Canadian Electrical Code (CEC), pertinent to upgrading old wiring.
Renew your old wiring for safety!!.
Remember that it’s no longer permissible to
ground to the closest metallic water pipe. The CEC allows a separate ground wire
to be run to an outlet to provide an equipment ground. The added wire must
originate from the panel ground bus, and it must closely follow the
current-carrying conductors of the circuit. If you’re going to run a wire all
the way back to the panel, you might as well run a new cable with ground.
Old fixtures sometimes are attached to framing with no electrical box to contain the connections between building wire and fixture wire. The boxes that were used later typically are too small by modern standards. Boxes must be part of a new installation. Old boxes usually need to be replaced to meet code.
System grounding protects your house and its wiring from energy surges like lightning strikes and high-voltage power-line contact with local distribution lines. The CEC’s requirements for system grounding have changed considerably over the years. This is a big safety issues with residential wiring. When upgrading a service, be sure that the system grounding is brought up to meet requirements in your area.
Finally, to meet the demand of modern
energy uses, the CEC requires installation of several specialized heavy-duty
circuits. For
instance, the CEC mandates a minimum of two 15-amp circuits to serve
kitchen-countertop outlets, a 30-amp circuit for the
laundry, and a 15-amp circuit to serve fridge. Requirements like these have
to be met when making changes to the wiring in these rooms or areas. They’re
smart to make pretty much at any time.