Inductive bolt heater question

[alia176]

I got two Hotshot units from Amazon, a 1300W and a 1500W. When I checked their power draw using a Kill A Watt meter, I noticed they draw around 350w and 500w. Is this how they're suppose to work?

In case you're curious as to why I have two heaters. They sent me the 1300w instead of a 1500w so i'll be returning the 1300w today, but I wanted to run this back to back test first!

Link to the item: https://www.amazon.com/dp/B0G51MZHFV?tag=ihco-20

Here's a video I took.https://photos.app.goo.gl/P2a3LPJPBADeByn5A

 

[george_tlc]

The power it draws will depend on how well the field from the coil couples to the bolt. Does the unit come with smaller diameter coils that are a more snug fit to the bolt head? As the bolt heats up, its ability to maintain the magnetic flux will drop (curie point) and power draw will drop.

Try a bigger diameter bolt head that better 'fills' the coil you have.

The big question - does the bolt get stinking hot? Obviously this will only work bolts that can have a magnetic field. Stainless will not heat as well. High iron content will heat more (and pull more power).

cheers,
george.

 

[alia176]

That makes a lot of sense George, thanks. I'll try the same test with a smaller coil and a larger bolt head. The bolt head did get red hot.