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MEP-803A wiring into the home

Hard Head

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The primary reason to select any breaker is to protect the circuit / wire. If you want 60 amps with a portable cord you would need a 4/4 which is rated at 60 amps. Rating for 6/4 is 45 amps, 6/3 is 55 amps and a 4/4 is 60 amps, and 4/3 is 70 amps. If you are using this on a 240 vs 3 phase use the 6/3 spec. You should not up your breaker to 60 on #6 wire.
 

DieselAddict

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You'll need to go by the rating for the actual cable you buy. It will be printed on the cable or on the label on the reel.
 

Daybreak

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Howdy,
Some information.
A single copper wire with insulation will have a certain amperage rating by itself.

A 4 wire group, in a covering will have a lesser amperage. The method and construction and materials used will be the determining factor.

#6awg wire/ 4 conductors, in a SOOW is rated at 45 amps
#6awg wire/ 4 conductors, TYPE W is rated at 87 amps
 

jaxbill

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FL
For my indoor wiring, I ended up going with THHN/THWN-2 4 AWG for the current carrying conductors and 6 AWG for the grounding conductor. I am going to use a 70 A breaker since my wire is rated for that much current and I read a few posts here some can support surges up to that rating. From the breaker, this wiring will terminate on a re-purposed 100 A DTDP switch because I want to keep my existing inlet for my portable generator. The metal case is slightly beat up but it will be mounted indoors and it will let me keep my existing 30A inlet as-is.

I'm also trying to find a way to put the generator closer to the house and that should eliminate voltage drop concerns. I might end up just using additional 4 AWG THHN in a conduit along the exterior walls and hard wire the generator. If I find I need/want a smaller breaker or exterior emergency disconnect, I may mount a small box on the side of the house like I have for my pool pump circuit.

If I wasn't worried about Type W cable deteriorating sitting outside 24x7 or the additional cost for it plus the connectors, I would go that route because I just don't know if my location is going to work out. I am a bit concerned hard wiring everything up and finding out I need to move the generator.

Thanks for everyone's help. I'll start an installation thread with pictures to show progress once I start the work. I need to re-arrange some circuits and my nearly fully loaded neutral/ground bars in the main panel first.
 

lynn896

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Question: No one in this thread mentioned the use of Type G Portable Power Cable, size 6 AWG 4 conductor rated at 70 Amps for portable hookup? Is there some reason this type of cable would not be suitable?
[h=2]http://www.wesbellwireandcable.com/Power_CableTypeG-GC/6-4-g-gc-multiconductor-industrial-power-cable-82624.html[/h]
 

mlaxton

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What we do on the construction site is to clamp an amp meter on each leg, and let it record the next 24 hours, (or longer) data. If you meter only records the highest reading, that's helpful also. At least you know what peak is.
So can I just go with the max output my 803 is rated at and then pick THHN that is rated far above that? I am not worried about saving a couple bucks. Is a 100’ run ok as long as the conductor is rated well above machine capabilities? Looking to hardwire permanently one a location.
 

LEOK

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There is so many ways of wiring it, what I've found if your building a remote hookup is 100amp service entrance aluminum 4 wire that is stocked and sold by the foot for direct burial, commonly used to hookup mobile homes. Little pvc conduit at both ends and ready to go. Regular breakers will only take about 65% of their rated load on a continuous bases. Special HVAC breakers are available but expensive.
 

Daybreak

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There is so many ways of wiring it, what I've found if your building a remote hookup is 100amp service entrance aluminum 4 wire that is stocked and sold by the foot for direct burial, commonly used to hookup mobile homes. Little pvc conduit at both ends and ready to go. Regular breakers will only take about 65% of their rated load on a continuous bases. Special HVAC breakers are available but expensive.
Howdy,
Do not believe what you have to say about breakers. You do not know what your talking about.
 

LEOK

Active member
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Location
Gainesville/Fl
NEC CODE
OCPD size = 100% of noncontinuous load + 125% of continuous load. Breaker size

Sec. 384-16(c) has the same requirement, except that it's stated in terms of the loading of the OCPD. This rule states that an OCPD can be loaded to only 80% of its rating for continuous loads. Remember that 80% is the inverse of 125% (0.80 = 1 [divided by] 1.25) and, as such, the rules are indeed identical in their end requirement

So yes my 65% rating for Continuous load is conservative but over the years on things pool heaters which draw full load for over three hours the breakers will degrade with time and after a year or two you will find them tripping.

If you look up the CB characteristic trip curves, you will see they are not linear, and heat gets to them, put them in a small service box in the florida sun will screw with them to.
 

2Pbfeet

Well-known member
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Mt. Hamilton, CA
Question: No one in this thread mentioned the use of Type G Portable Power Cable, size 6 AWG 4 conductor rated at 70 Amps for portable hookup? Is there some reason this type of cable would not be suitable?
[h=2]http://www.wesbellwireandcable.com/...nductor-industrial-power-cable-82624.html[/h]
I use type W. I went to using it after finding some SEOOW cable that was not rated for exposure to diesel. That seemed important to me.

Everything below is discussing copper wire and copper wiring.

Type G is closely related to type W in terms of performance (ampacity, and insulation/temperature characteristics). It has more ground wires as the common use of type G is in marinas where one cares a lot about the existence of a ground and its continuity. Type GC is basically type G with a ground check wire.

Both versions have fine wire for better longevity in repeated flexing (rolling and unrolling). Both are used in moving electrically powered machines, which is why these cables are mine safety rated (MSHA) because they are used in mines to power equipment. It is also why type W is the preferred cable type for the entertainment industry. They are much tougher cables than SEOOW/SOOW, with better abrasion resistance, better solvent resistance, and better flexibility. They are larger in diameter compared to their equivalent SEOOW cables, and their bending radius is larger, so your cable spools should have larger inner diameters.

Both type G and type W are typically a higher temperature rated cable (90C or 105C), and that results in higher allowable currents, but only if the connectors/breakers are also rated for 90C or 105C. (Many are, but check.) They are also usually rated for 2,000 or more volts.

Finally, to an earlier incorrectly stated point about amperage ratings, the wire or cable rating is for the maximum current at the maximum temperature. The voltage drop (V=IR) comes from the current actually going through the cable. A 6ga wire has about 0.4ohms per 1000', so 55 amps going down and back a 50' 6ga run will have a 2% voltage drop. If you run a lower current, the voltage drop will be less. Also, the total power loss would be 121W over the same 6ga set up (Power lost is = I*I*R) Switching to 4ga would drop the loss to 72W. The 49W savings might be important to you, or not.

The full NEC flow chart for cable ratings is here;

Note: the above table covers current carrying conductors, i.e. Not grounds. Derating to the maximum current allowed applies for three phase cable uses if the neutral carries current. (80% in the three phase + active neutral = 4 conductor case) Finally, current carrying capacity gets reduced as the outside air temperature goes up.
e.g. At 105F, your 6ga cable is derated 13-29% (90C cable to 60C cable). That goes for your in conduit wiring as well.

FWIW: Most of the surplus 50A+ cables that I have seen are type W.

I can't speak for other places, but locally running conduit with 6ga THNN wire is 50% more expensive than type W, but you do have the hassle of wrangling reels of bulky cable if you don't hard wire the bulk of the run. (And here 6ga THHN copper wire isn't easy to come by.)

All the best,

2Pbfeet
 
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