An Old Goat Ranch in Texas

[bdeboer]

OMG - ANOTHER chart / calculator....:confused2:

You know the old saying...."A man with one watch knows what time it is....a man with two watches is never sure..."

I AM going for 240VAC via three conductors, buried in conduit...

I rather hope your chart is right....your conductors seem a bit small according to the other "calculators"....

My math skills are right up there with my abilities at diplomacy, so I am hoping somebody can help me navigate the Code and make some sense of all this...

Thanks for the link...I will study this some-more and get back to you...!

BE SAFE!

You are on the right track with the voltage drop calculators. If you go with #6 wire the voltage will drop be closer to 7% for 300'.

 

[terry.dinerman]

Are you planning using direct burial, or are you going PVC with individual conductors? Using #4 copper the voltage drop would be about 4.9% vs. 3.1% for the #2.

Voltage Drop Calculator

I was planning on burying conduit...

T

 

[terry.dinerman]

You are on the right track with the voltage drop calculators. If you go with #6 wire the voltage will drop be closer to 7% for 300'.

Aight, Brian...

That Voltage Drop Calculator is pretty self-explanatory, but I am still confused....

The calculator recommends no more than a 5% voltage drop as desirable.

Running the calc with the amps and wire size as variables, here are my inputs.....

240 v
4 awg/ 6awg
50 amps / 60 amps
Single phase
Copper conductor
75C
PVC conduit
Single set of conductors
300 feet

This returns the following....

#4 awg = 3.9% OR 4.7%

#6 wire = 6.2% OR 7.4%....

Thus, to my mind, #4 awg is slightly over-engineered for a 50 amp service and near ideal for 60 amp, whereas #6 seems undersized for either service.

My question is....would the up to 2.5% more voltage drop even noticeable if I go with the smaller conductors?

Obviously I could run 2/0 wire and reduce it considerably....but my budget likes your design spec of #6 a lot more....

What do you think?

T

 

[dcyrilc]

Hey Terry,

With a 300 foot run, don't go smaller than #4. Personally, I'd use #4 for a 50A or #2 for the 60A, but then again that's just me. You probably won't notice the difference using the #4 at 60 A.

At 60A the #6 calculates out to a loss of 8.88 volts on 120V (each leg of your 240V). Assuming that you're starting with a solid 119V (pretty common for a good 120V service measurement) you will be down to 110V. That's a pretty substantial loss.

 

[greasemonkeyok]

Enjoyed the read. Had to go all the way back to the first post ascertain whether the adjectives in the tag line referred to the owner or the livestock.

 

[valley]

Man, I'm glad I found this thread or book or chronicle! I'v just read part of the first page and am sure to get back with more time to enjoy. Please carry on.

Richard

 

[terry.dinerman]

Enjoyed the read. Had to go all the way back to the first post ascertain whether the adjectives in the tag line referred to the owner or the livestock.

Well....according to some folks (Precious Bride especially) it refers to BOTH...

 

[terry.dinerman]

Man, I'm glad I found this thread or book or chronicle! I'v just read part of the first page and am sure to get back with more time to enjoy. Please carry on.

Richard

Thank you for taking the time to read!

This has been a grand adventure so far, and I am delighted to record it and share it in this way...let me know what you think and CERTAINLY give me all the advice you dare...

I need all the help I can get!!!

 

[terry.dinerman]

Hey Terry,

With a 300 foot run, don't go smaller than #4. Personally, I'd use #4 for a 50A or #2 for the 60A, but then again that's just me. You probably won't notice the difference using the #4 at 60 A.

At 60A the #6 calculates out to a loss of 8.88 volts on 120V (each leg of your 240V). Assuming that you're starting with a solid 119V (pretty common for a good 120V service measurement) you will be down to 110V. That's a pretty substantial loss.

How Doo, Cyril-

With the brain-haze now starting to clear, thanks to all the advice coming in, I am leaning heavily towards a run of #4 on a 60 amp breaker...the source panel is barely 10 feet from the transformer, and I am the ONLY user on it, so that should give me a rock solid supply...and there is nothing exotic going into the barn...if you remember, it is just 4 truck bodies...window-unit AC, some lighting and hand power tools are the main use...

I got a great deal on some 4" PVC pipe which I will use for the conduit...so down the road, I could even pull another set of conductors and go power-mad...

I still have a few days to mull all this over before I rotate back to the US...and I am waiting to see what our TBNet "EE" (bdeboer) has to say...I am still confused at why one calculator uses a formula that includes 50% of the run length vs another that uses 100%...tho I tend to trust the calcs that HE trusts...

Needless to say, in any case, I am going to have to stock up a box of cheap cigars and a jug of the Good Stuff in case any of my vast and underpaid advisory staff happen to have the great good fortune to find themselves in my part of Texas....

 

[dcyrilc]

How Doo, Cyril-

With the brain-haze now starting to clear, thanks to all the advice coming in, I am leaning heavily towards a run of #4 on a 60 amp breaker...the source panel is barely 10 feet from the transformer, and I am the ONLY user on it, so that should give me a rock solid supply...and there is nothing exotic going into the barn...if you remember, it is just 4 truck bodies...window-unit AC, some lighting and hand power tools are the main use...

I got a great deal on some 4" PVC pipe which I will use for the conduit...so down the road, I could even pull another set of conductors and go power-mad...

I still have a few days to mull all this over before I rotate back to the US...and I am waiting to see what our TBNet "EE" (bdeboer) has to say...I am still confused at why one calculator uses a formula that includes 50% of the run length vs another that uses 100%...tho I tend to trust the calcs that HE trusts...

Needless to say, in any case, I am going to have to stock up a box of cheap cigars and a jug of the Good Stuff in case any of my vast and underpaid advisory staff happen to have the great good fortune to find themselves in my part of Texas....

I might recommend putting a box or two in along the run to make the pulls easier. They wont need to be as big as the ones used on the power run for the primary, but they are nice to have. They also give you a point to run other conduits from for things along the way later.

Be safe and stay cool. Maybe one of these winters when the rain is getting to me too much we might be able to make it down your way at a time when you're state side. There's a few TBN members down your way that I'd love to have a chance to meet.:thumbsup: