Using Kynar 30AWG for 120VAC

[eccerr0r]

I saw this and

Granted this looks like a homebrew and at least 30AWG wire should fuse on its own if it shorts out...

[stj]

Re: Using Kynar 30AWG for 120VAC

that's fine,
the conductor is rated for 300v, the insulation breaks down at 2000v

[eccerr0r]

Re: Using Kynar 30AWG for 120VAC

Most kynar 30AWG wire has "no spec" by UL for voltage, granted, kynar is fairly tough, hard to scrape the insulation. But it's much thinner than any other UL listed wire.

UL does spec 105°C for max temperature which is probably good enough.

Military spec kynar wire is good for 300V at least however. Not sure what the difference is other than 135°C.

Now the question is whether it's good enough for 220VAC... now that is pushing it.

[stj]

Re: Using Kynar 30AWG for 120VAC

data

[eccerr0r]

Re: Using Kynar 30AWG for 120VAC

Yeah, "no voltage rating" is the key words that I see on many spec sheets - it's not rated for voltage like other wire. The conductor itself will handle 300V but who knows how close the other potential is... Usually these wires are used for less than 50V typically so nobody cares too much.

I did not know typical wire wrapping Kynar wire were silver plated, thought it was tin. Nice, supposedly these should be pretty good for its diameter for RF.

[budm]

Re: Using Kynar 30AWG for 120VAC

https://jaguarind.com/kynar-wire-tefzel-wire-wrap/

[redwire]

Re: Using Kynar 30AWG for 120VAC

It would be OK as long as there is a suitable fuse to prevent a fire hazard from over-current glow or melting.

#30 AWG can carry around 1A max. before the insulation heats up too much, 105C, and 10A for 30 seconds before melting like a fuse.

It's dangerous here because a hot wire would melt the electrical tape, transformer bobbin, and using #30AWG for protective earth-ground is forbidden in electrical codes.

[eccerr0r]

Re: Using Kynar 30AWG for 120VAC

Fortunately (???) the black wire isn't being used for chassis ground but rather as a common point tie. Whether one is allowed to share the main ground tie (green wire) with the thin black wire is acceptable, but it's probably okay.

I think the maximum "normal" current flow is around 20mA or so estimated, so nowhere near the current limit fortunately. So unless something bad happens, the gauge is fine. Unfortunately no fuse or power switch on the primary -- it's a homebrew.

Might have to add a fuse, but seems like one would need a fuse of 200mA or less or so, else the wire may fuse before the fuse. And those milliamp fuses are expensive...

[stj]

Re: Using Kynar 30AWG for 120VAC

Iusing #30AWG for protective earth-ground is forbidden in electrical codes.

your codes are a joke though,
i was just watching a video where a guy has a hotdog grill - explosed metal grill&rollers etc.
and it only had a 2pin plug!!!
https://www.youtube.com/watch?v=CFILmL1E2U8

[eccerr0r]

Re: Using Kynar 30AWG for 120VAC

At least it's not a coffee-cutor...

[stj]

Re: Using Kynar 30AWG for 120VAC

but the handheld elements have a handle and are obvious.
besides, you have to unplug them before moving them because of the heat.

the hotdog thing, you have to touch it to remove the food.
and you DONT EXPECT the metalwork to be live - but it could with no fucking earth wire!!

i find it strange, because my line of work - amusement equipment,
all u.s. origin stuff has literally every exposed bit of metal earth-bonded - even hinges have a braid running to them.

yet this METAL cooking device does not even have a 3pin plug!!

[eccerr0r]

Re: Using Kynar 30AWG for 120VAC

Then again, common toasters have 2-prong plugs too... or do they not?

[stj]

Re: Using Kynar 30AWG for 120VAC

not in europe they dont.

the rule is simple, if there is any exposed metal then it must be earthed.

[redwire]

Re: Using Kynar 30AWG for 120VAC

Earth-ground was added to North American electrical codes, for outlets, plugs, many appliances in 1962.
I don't know if Europe ever had ungrounded outlets or appliances. UK seems to have many different plugs.

1970's product that hot dog cooker. Newer ones have an on/off switch with the lid. I remember it made terrible tasting hot dogs if there was power-line sine-wave distortion, a slight net DC offset gave you some zinc flavour. Yuck.

Another product of the era was a baby bottle warmer, with two mains electrodes in a cup base and you fill with water. The water boils and warms the baby bottle.
But hard water did not do much (Ca, minerals low conductance) so you had to add a little salt or baking soda and if you put in too much you had 15A flowing through a boiling froth that was pretty scary loud. They were not safe.

[RJARRRPCGP]

Re: Using Kynar 30AWG for 120VAC

Newer ones have an on/off switch with the lid. I remember it made terrible tasting hot dogs if there was power-line sine-wave distortion, a slight net DC offset gave you some zinc flavour. Yuck.

Was that a cheap hot dog cooker?!

I don't like the sound of the mention of on/off switch with the lid. What I picture, is something that's cheap! (A good chance that they're from a Chinese company whose name I never even heard of!)

(if you mean the switch on the lid!)

[PeteS in CA]

Re: Using Kynar 30AWG for 120VAC

I sure do not love the soldering on the power cord wires (IIRC, White = Neutral is US usage).

[eccerr0r]

Re: Using Kynar 30AWG for 120VAC

Yeah pretty sure it's a homebrew versus a low quantity(and quality?) build, the solder job is indeed crappy, and if you only have blue and black 30AWG Kynar®, blue and black 30AWG Kynar gets used.

[stj]

Re: Using Kynar 30AWG for 120VAC

big clive has been playing with the old hotdog electrocutors recently!

[budm]

Re: Using Kynar 30AWG for 120VAC

The company claimed that it is ETL approved, I doubt it very much.
https://www.amazon.com/dp/B000HK20BA...l_huc_continue

[eccerr0r]

Re: Using Kynar 30AWG for 120VAC

Interesting, it's only 280W, so less than a toaster.
I don't know, I suppose the US now having GFCIs pretty much standardized, that's probably why the appliance manufacturers can leave it ungrounded. *shrug*

But this homebrew actually has a grounded 3-prong plug surprisingly enough, unlike my old tube tester... it has a 2-prong plug and a metal chassis...