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[Reply #30 on:]

It needs to be connected with one cable.

Why one? Where did this requirement come from?

Because customers would prefer to buy and string up one cable vs two side-by-side.

I figured this was for your own use. I shouldn't make such assumptions. 
 
 That's different, the customer is always right. In that case just present to and have your customer sign off on a waiver of all fault and liability for your work and run it all through your cat5 cable. Be sure you have your attorney draw up the document as some liabilities cannot be transferred or waived.

Lefty

Waivers aren't going to help you when somebody gets killed. If anything it will show you knew it was dangerous and did it anyway.

That's why I stated the last sentence.

[Reply #31 on:]

Because customers would prefer to buy and string up one cable vs two side-by-side.

I figured this was for your own use. I shouldn't make such assumptions.

Actually, this makes the problem much simpler. If you sell stuff to people that connects
to the power mains, and you didn't get UL agency approval, and it burns down their house,
then you both get sued and the govt puts you in jail. Totally illogical.

[Reply #32 on:]

And we have documented here that David82 was repeatedly advised against such reckless behavior - that will certainly not play well in the inevitable lawsuit that David82 will be answering to, as he seems hellbent on moving forward with this blatantly hazardous endeavor.

[Reply #33 on:]

he seems hellbent on moving forward with this blatantly hazardous endeavor

It would be hilarious if David82's client was an Arduino hobbyist and read this thread, thinking "Hmmm, this looks just like that project at the office.... wait a minute, pretty sure it is the project at the office... does this guy know Jack Schitt about this stuff we're paying him to do?"

[Reply #34 on:]

Some very odd claims here.   A 7A power supply is the low voltage current.   Not the high voltage current.

A 7 Amp low voltage power supply is going to be requiring well under 1 A on the mains supply side,  so as far
as current capacity is concerned,   that is the figure you should be comparing the capacity of the cable to.

You are more likely to have inadequate insulation capability,  than current constraints.

[Reply #35 on:]

You'd still be running a Cat5 cable close to, or exceeding, it's DC current rating. WIth a long length than thatwll introduce I2R losses in the cable. These losses are simply heating effects due to the resistance of the conductor. That means heat. Heat means de-rating current carrying capacity AND insulation resistance.

The fact it would also be an AC supply, which the cable is NOT designed for, rings a big fat NO.

It's very very simple really, he states it's for a customer, that means you have to use materials that are rated for the purposes you want to put them to. Using a Cat5 cable for a mains AC supply is NOT what it is designed or rated for.

AC and DC are two totally different things, with different characteristics of stress and leakage currents. A cable acts like a capacitor. When you test a cable at DC it will take a charging current initially and then settle to a steady (you hope low) leakage current. If you test at AC power frequency (50 or 60Hz) that capacitance is charged and discharged repeatedly in opposite polarity and you get appreciable larger AC leakage current. It's the same as in an electronic circuit, a capacitor blocks DC and, depending on the value and applied AC frequency, will have differing effect on AC from a hgh reactive impedance to virtually none.

I get involved in low (up to 1000V) and high (up to 33,000V) testing and there are many different insulation types and ways of testing each one, from DC to AC power frequency (50 or 60Hz) and AC Very Low Frequency (0.01 to 1Hz). Insulation of a particular cable is designed to withstand the type of voltage it is intended to carry.

If you use a cable for a purposes it's not intended for then you can't guarantee how it will hold up under those conditions.

[Reply #36 on:]

David82, I think that you should STOP trying to do something that may cause injury or death, and may cause damage to property. You CAN'T try to run 120VAC current through Cat5 cables. If you don't believe me, connect two thin wires to a powerful battery (battery pack for R/C cars). Touch the wires together and watch the insulation melt.

[Reply #37 on:]

Where can we send the electrical inspector ?
I wonder what else is terribly wrong.

[Reply #38 on:]

Here's a simple way to look at it - there's a reason why the AC wiring in your house is 14AWG copper wiring and not 26AWG copper wiring...

[Reply #39 on:]

Here's a simple way to look at it

Here's an even simpler way of looking at it.... if the OP has to ask about mains wiring on a forum, he's not qualified to sign off on the work... Period.

[Reply #40 on:]

Here's an even simpler way of looking at it.... if the OP has to ask about mains wiring on a forum, he's not qualified to sign off on the work... Period.

There's really no getting past that.