I recently purchased a century-old home that still has some knob and tube (K&T) wiring. In the basement, there are two electrical panels: one seems updated with modern wiring, while the other is definitely K&T. I'm trying to figure out an easy method to determine if a specific outlet is connected to the K&T wiring. Also, is it safe to use a power strip with any outlets that are powered by K&T?
3 Answers
You can check the outlets by plugging a light into them and then shutting off the power to the panel that you suspect has the K&T wiring. If the light goes out, you've found your answer! It might be a good idea to keep track of which outlets are connected to K&T as a reference. For the modern panel, using a three-prong circuit analyzer is a good idea to see if the outlets have proper grounding; if they do, they probably aren't connected to K&T, but it’s not a foolproof method.
Knob and tube wiring usually lacks grounding, so using a probe to check if there's a ground at the outlet could provide clarity. Be cautious though, as modern electronics don't align well with K&T wiring and it can degrade over time. While it might seem okay most of the time, why risk it? Getting an electrician to evaluate your situation is a smart move.
To check if an outlet is from the K&T system, plug in a lamp and then turn off the breakers associated with that panel. Observe which lights go out. Ideally, you want to make sure your appliances are hooked up to the newer panel for safety. If you're unsure, contacting an electrician might be the best route.