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.
Excessive voltage drop at outlet cause induction cooktop to not work
Jan 24, 2021
Last reply: 5 years ago
9 Replies
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.
You may have a bad connection at the outlet. Is it warm to the touch, even the plastic parts? When being used for cooking.
Maybe one or both screws is loose. Less likely but possible, the wire is cracked.
Possibly the other outlets youve checked are not on same breaker, in which case the bad connection could be AT the breaker.
I suppose it could be internal to the receptacle, the metal tab broke inside. I've never heard of this except for this one time wheh they weren't broken, just tired**, but if the recept. is warm, or hot, the problem is the receptacle or within an inch of it.
**I one time had a room heater plugged into a one-plex receptacle in a building built in 1930. It was about 1980. I woke up to see one inch flames coming from the hard rubber plug of the heater. I don't know how long it was burning. Pulling out the plug made the flames go out. The receptacle was old, it didn't squeeze the prongs of the heater like it once did, it provided electrical resistance and got hot, accordign to Power = amps x volts where the volts are the voltage drop at that spot. And the amps are what the heater drew, even though it was drawing a little bit less because of the voltage drop.
On line side or probably load side (in this case), the the three passive linear circuit elements of power processing that remove a properly calculated voltage drop are an inductor, capacitor or a resistor.
I suppose but that is about 300' of #14 to drop 15 v at 8.33a
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.
That is a good place to use your IR gun.
On Sat, 23 Jan 2021 21:41:04 -0500, snipped-for-privacy@aol.com posted for all of us to digest...
Wouldn't a thermal camera be wonderful to have?
Maybe that Covid fever thermometer gun you bought? ;-)
One place you might want to check is the push-in type outlets. I have a
15 amp circuit in the livingroom. At Christmas I used to have a tree with several hundred C7 incandescent lights. Some were 7 watts and others were 4 or 5. I was getting a huge voltage drop. The tree lights were about 5 outlets from the line to the breaker. All used push-in connectors on the outlets. I found the outlets before the Christmas tree were warm to the touch. After using wire nuts and the screws connections on the outlets, the voltage drop verturally dissappeared. All a mute point now as the C7 lamps have all been replaced by LED C7s.Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required