If It's 80 Ft Long Wire (20amps) A Considerable Problem For Voltage Drop? - Electrical - Page 2 - DIY Chatroom Home Improvement Forum

 DIY Chatroom Home Improvement Forum If it's 80 ft long wire (20amps) a considerable problem for voltage drop?

 Thread Tools Tweet Share Display Modes
04-25-2019, 10:45 AM   #16
A "Handy Husband"

Join Date: Feb 2007
Location: South Carolina Low Country
Posts: 9,511
Rewards Points: 388

## Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?

Quote:
 Originally Posted by bob22 Southwire has a calculator that when I ran it for 80 feet delivering 20 amps said you need 10 awg. Site: https://www.southwire.com/calculator-vdrop
Southwire is in the business of selling wire.

Sent from my Moto E (4) Plus using Tapatalk
__________________
My electrical answers are based on 2014 NEC, you may have local amendments.

Location: Coastal South Carolina

04-25-2019, 11:04 AM   #17
Deleted Member

Join Date: Nov 2017
Posts: 429
Rewards Points: 858

## Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?

Quote:
 Originally Posted by bob22 Southwire has a calculator that when I ran it for 80 feet delivering 20 amps said you need 10 awg. Site: https://www.southwire.com/calculator-vdrop
Makes sense, since with a continuous 20A feed, you would need a 30A circuit

04-25-2019, 11:20 AM   #18
Member

Join Date: Mar 2018
Posts: 97
Rewards Points: 192

## Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?

Quote:
 Originally Posted by bob22 Southwire has a calculator that when I ran it for 80 feet delivering 20 amps said you need 10 awg. Site: https://www.southwire.com/calculator-vdrop
Ok now this got me confused.
I can't do a #10 wire as I'm doing a junction box, as both side the wire should be same and I can't change what's in the wall now. If I'm having a voltage drop issue then I have to move the AC condensor and run another conduit from the main panel and do a subpanel. I was under impression yesterday that #12 wire should be ok for 80 feet and no worries at all.
(A.C. wires are thicker because the breaker is larger than 20 amp)

Thanks

04-25-2019, 11:26 AM   #19
Member

Join Date: Jan 2013
Location: Lake Orion, MI
Posts: 133
Rewards Points: 238

## Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?

Quote:
 Originally Posted by rockman413 Why your calculation is very different from KPD's (see the 2nd or 3rd post)
I think I know why....truth be told it is correct to say there is a 2.5V drop to the load. However, there is a 2.5V drop from the load back to ground. This results in a 2.5V ground offset so if you measure your voltage across your device you would see 115V. However the potential to the device is 117.5V.

04-25-2019, 12:38 PM   #20
Member

Join Date: Mar 2018
Posts: 97
Rewards Points: 192

## Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?

Quote:
 Originally Posted by Sdiver2489 I think I know why....truth be told it is correct to say there is a 2.5V drop to the load. However, there is a 2.5V drop from the load back to ground. This results in a 2.5V ground offset so if you measure your voltage across your device you would see 115V. However the potential to the device is 117.5V.
Got it. But why I'm seeing people saying that could be problem and ask me to use a thicker wire? I'm so confused...

04-25-2019, 01:02 PM   #21
Member

Join Date: Aug 2017
Posts: 3,075
Rewards Points: 6,148

## Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?

Problem is, as far as I can tell, we still don't know what the op is trying to do.

What's the rated voltage and current of the load?

Unlikely the rated current is 20A but if it is that's quite different.

Without this basic info this is all a waste of time.

04-25-2019, 01:05 PM   #22
Member

Join Date: Mar 2018
Posts: 97
Rewards Points: 192

## Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?

Quote:
 Originally Posted by CodeMatters Problem is, as far as I can tell, we still don't know what the op is trying to do. What is the load? A/C? What's the rated voltage and current of the load? Unlikely the rated current is 20A but if it is that's quite different. Without this basic info this is all a waste of time.
Ok, most load would be home devices such as cell phone charger, TV, computers, etc. (kitchen stuff is on another subpanel already)
Pool Pump which I guess has a thicker wire
AC units which has a thicker wire

So it looks like it's only the home devices that's on the #12 wire.

04-25-2019, 01:08 PM   #23
Member

Join Date: Aug 2017
Posts: 3,075
Rewards Points: 6,148

## Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?

Quote:
 Originally Posted by rockman413 Ok, most load would be home devices such as cell phone charger, TV, computers, etc. (kitchen stuff is on another subpanel already) Pool Pump which I guess has a thicker wire AC units which has a thicker wire So it looks like it's only the home devices that's on the #12 wire.

So are you talking about 3 circuits?

04-25-2019, 01:10 PM   #24
Member

Join Date: Mar 2018
Posts: 97
Rewards Points: 192

## Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?

Quote:
 Originally Posted by CodeMatters So are you talking about 3 circuits?
3 kinds of circuit:

1st kind: Home devices such as cell phone charger, computers, TV, excluding kitchen stuffs (already on another subpanel)

2nd kind: Pool Pump, probably have a thicker wire which has no worries over long distance.

3rd kind: AC units, have a thicker wire which has no worries over long distance.

04-25-2019, 01:26 PM   #25
A "Handy Husband"

Join Date: Feb 2007
Location: South Carolina Low Country
Posts: 9,511
Rewards Points: 388

## Re: If it's 80 ft long wire (20amps) a considerable problem for voltage drop?

Quote:
 Originally Posted by rockman413 3 kinds of circuit: 1st kind: Home devices such as cell phone charger, computers, TV, excluding kitchen stuffs (already on another subpanel) 2nd kind: Pool Pump, probably have a thicker wire which has no worries over long distance. 3rd kind: AC units, have a thicker wire which has no worries over long distance.
This is like pulling teeth to get info to give a reasonable answer.
__________________
My electrical answers are based on 2014 NEC, you may have local amendments.

Location: Coastal South Carolina

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are Off Pingbacks are Off Refbacks are Off Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post BCS Electrical 33 03-20-2016 11:30 PM wicked97 Electrical 4 08-21-2011 08:12 AM Confuserated Electrical 9 02-12-2010 03:30 PM Howdy Electrical 3 03-14-2008 08:23 PM ScubaRaven Electrical 11 06-08-2006 02:32 PM

Top of Page | View New Posts