On Saturday, January 23, 2021 at 9:41:36 PM UTC-5, wrote:
On Sun, 24 Jan 2021 01:00:59 +0000, jay
wrote:

I have an outlet with excessive voltage drop when I plug in an induction cooktop (1000 watt). The outlet measures 120 but the voltage drops to 105 when the cooktop is plugged in. The cooktop stops working because of the low voltage. This does not occur in other outlets.
You have a bad connection somewhere between there and the panel. I
would start with the receptacle right there and then try to trace it
back one at a time until you find the bad one. If they are back
stabbed, it is far from unusual. You may see signs of overheating. You
are creating about 125 watts worth of heat in that bad connection.

If there are other receptacles upstream of this one, localizing the bad connection
could be as simple as measuring the voltage at the other ones while the
cooktop is running. If the voltage suddenly increases, the bad connection
is somewhere after that. And it should be fixed, if that's due to one bad
connection that's enough heat to start a fire. Could also be a bad
receptacle at the cooktop too.