Wire temp question

Talking about Quicksilver is really jacking this thread.

But I will say, she is wired almost 100% with Space Shuttle Discovery and Endeavor, surplus "refit" (new) wire. Orange blue and white. Tefzel. And DuPont Kapton insulated wire, and five different gauges of good old fashioned teflon FAA grade wire. Eat your heart out I bought the wire at the Lockheed surplus auctions held on Saturdays in Palmdale for .50 pound. I used to go with Pat Tuminaro, the then Snap On tools dealer.

The wire is stiffer than a ******* *****. I had to slop on a ton of wire lube to pull it through the EMT. RV's do not lend themselves to wire sweeps so I had to use pull-ells. Come-along and blue streak language coaxing. Chinese - Fingers and nylon twine. There are triple 1" EMT runs down port and starboard. Pull Tees at each receptacle junction. I lucked out big-time and found a crate of 90 degree #6 forked terminals at Halted Electronics (and a pallet of 1000va full isolation transformers).

Not about the bus. It has a 400-HP 855 Cummins upgrade with a Fuller 13-speed and SQHD rear axle. Loaded to near Max GVW it gives 13.5 mpg and climbing a 6% grade for 110 miles almost 9 mpg

A 10 dollar taxi ride from a very remote RV park each way to town plus 21 dollars for a night, cannot compare with a twenty one dollar room right on the plaza. That and the park entrance is too narrow for comfort. The paint and mural cost me almost four grand 30 years ago.

2oldman wrote:
If your wire is heating up you need bigger wire.

I love this thinking. Less is MORE!

A few other exceptions. If your supply voltage drops, many loads will try to suck more current causing the wire to heat up. So, you must also check the rated supply voltage especially on lower voltage systems. (12 Volt) Often, it's the wire CONNECTIONS that fail before the wire itself.

Chum lee

2oldman wrote:
If your wire is heating up you need bigger wire.

Generally speaking this is excellent advice. I will mention ONE exception below.
If the wire feels warm to the touch. use bigger wire.

The exception:

I layed out about 100 feet of mostly 8GA wire to power a couple of ham radio stations for a Field Day operation 100 watts max means about 10 amps max draw on the line. Now 8ga can take like 50 amps.

Well when I went to roll up this wire I had to wear gloves the wire jacket was so hot.. That is till I got into the area where the wire was SHADED and then it was COLD to the touch.. The heat was from the SUN. not the current.

I see said the blind man. I can’t do hands and knees anymore, unless I fall down.

I’m guessing she never saw north of five mpg?

What isQuicksilver?

A 70 passenger 10-wheel Crown School Bus that swallowed tens of thousands of dollars in the eighties and early nineties. Foolish? Didn't seem to be when I was using a snow shovel to feed it US currency. I promised myself to get a camera and share images of both it and my generator and battery shed. Times have changed radically in Mexico and in my personal health. What used to be forty dollars in fuel, and fifty dollars in RV park fees and toll road charges now measures in the several hundreds of dollars. So Quicksilver sits. And along with an umbilical tiny house serves as my hideout. The house requires three hours a week to clean, Quicksilver has oak and teak and very limited black water drainage capacity. It takes more than a dozen hours a week on hands and knees to clean -- I simply cannot do the hands and knees thing anymore. So being cabled to the ground it serves as a last ditch hurricane bunker, and food refrigeration and freezing addition.

I think the least expensive UL listed wire has insulation good for 80C/170F. That is still too hot to hold.

Current ratings for wire are based on the insulation type & specs and you will find a table in the NEC. THHN for ex. is UL listed for 90 degrees C. Components that wires connect to can have max. temp. ratings too like circuit breakers for ex. (90 degrees C). 90 deg. C wire is very common for building wires (and RVs). The Code specifies the max. current

Wire can also have a "free air" rating which is literally for wire hanging in free air, like in service drops to buildings. Current ratings for "free air" rated wire can be much higher for the same gauge when used in conduit or is in a cable in a wall.

Then you've got different current ratings for DC versus AC wires. There's also some situations where the same wire gauge can have a "continuous" rating and "non-continuous" rating. Here in Canada, it's permissable on fixed heating circuits to be able to run at full current but the breaker has to be derated to 80%.

MEXICOWANDERER wrote:
Temperature "absolutes" are tricky when it comes to electrical wire.

By referring to a NEMA chart and observing gauge, length and amperes you can avoid getting into a contest that is befuddling.

For instance multiple wires run in a raceway EMT tubing need a certain leeway depending on tubing diameter and number of wires.

For automotive use special insulation called CROSS LINK is specified for areas like passing near hot exhaust manifolds and exhaust pipes.

Multiple wire cables like THHN have two layers of insulation. Temperature of the conductor can become much higher than in the same wire without duplex insulation.

High temperature raises havoc with terminations. Where copper meets the terminal.

Personally I call things quits if wire insulation is >30c Delta T over ambient. This level to me means shut the power off. Underhood wiring in motor vehicles has traditionally taken a beating from the heat. Insulation that chips off, or cracks. Ford Diesel battery cables are special case of wrong material for the job. I use DLO locomotive cable and LEAD plated COPPER terminals for vehicles that may have another ten years of life in them.

The best way to view conductor heating is to avoid it. If the wire is being heated by convection or radiation I would consider using Cross Link.

I ran wire in Quicksilver in one inch EMT. 10 AWG main and 14 gauge green ground. Overkill. When I connect to a 108 volt overnight receptacle a minimum of added drop helps brew coffee faster :)

For amplification if you wish the National Elecrical Manufacturer's Association NEMA has more regulations and addendum's than you can shake two sticks at...

What was Quicksilver?

If your wire is heating up you need bigger wire.

Temperature "absolutes" are tricky when it comes to electrical wire.

By referring to a NEMA chart and observing gauge, length and amperes you can avoid getting into a contest that is befuddling.

For instance multiple wires run in a raceway EMT tubing need a certain leeway depending on tubing diameter and number of wires.

For automotive use special insulation called CROSS LINK is specified for areas like passing near hot exhaust manifolds and exhaust pipes.

Multiple wire cables like THHN have two layers of insulation. Temperature of the conductor can become much higher than in the same wire without duplex insulation.

High temperature raises havoc with terminations. Where copper meets the terminal.

Personally I call things quits if wire insulation is >30c Delta T over ambient. This level to me means shut the power off. Underhood wiring in motor vehicles has traditionally taken a beating from the heat. Insulation that chips off, or cracks. Ford Diesel battery cables are special case of wrong material for the job. I use DLO locomotive cable and LEAD plated COPPER terminals for vehicles that may have another ten years of life in them.

The best way to view conductor heating is to avoid it. If the wire is being heated by convection or radiation I would consider using Cross Link.

I ran wire in Quicksilver in one inch EMT. 10 AWG main and 14 gauge green ground. Overkill. When I connect to a 108 volt overnight receptacle a minimum of added drop helps brew coffee faster :)

For amplification if you wish the National Elecrical Manufacturer's Association NEMA has more regulations and addendum's than you can shake two sticks at...