Voltage drop and landscapers

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djtazjr

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What is the proper sized conductor to be used for 10 amp 120 landscape transformers with the distance of the run being 2000 feet.

We did a project recently with Landscape transformers requiring 10 amps 120 volts and my super used #4. I thought is was something different.

Anyway, if you need more info I will feel in if possible.
 
tom baker

tom baker

First Chief Moderator
Staff member
Location
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Re: Voltage drop and landscapers

What voltage for the 2000 feet?
The answer is based on ohms law. Take the DC resistance of the conductor and load, determine the voltage drop for each segment. The DC resistance in found in Chapter 9 of the NEC.
 
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djtazjr

Member
Re: Voltage drop and landscapers

2000 feet 10 amps 120 volts.

I did the cals. but wanted to see what the more experienced would say. I think my super is wrong with this apprication.
 
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jimwalker

Senior Member
Location
TAMPA FLORIDA
Re: Voltage drop and landscapers

There is no code on voltage drop , just a sugestion of 5%
If these bulbs are say 12 volts and get 11 i don't think anyone will notice and the bulbs will last longer.If he sized this to stay within 3% he did a fine job.
 
iwire

iwire

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Location
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Re: Voltage drop and landscapers

Originally posted by djtazjr:
2000 feet 10 amps 120 volts.
Click to expand...
Assuming you only have one load of 10 amps at 2000' the 4 AWG will result in 10.3% voltage drop.

Once you run this through the landscape transformers you will end up with about 10.4 volts at the 12 volt lamps, this will be noticeable.

To keep this at 3% drop would require 3/0 copper.

If you can live with 5% drop you could use 1/0 copper.

As this is most likely a 20 amp circuit you need a full size ground, so if you have run the 4 awg for voltage drop you must run 4 awg for the EGC.

I doubt your "super" wants to run the 3/0 or even the 1/0.
 
bob

bob

Senior Member
Location
Alabama
Re: Voltage drop and landscapers

What is the proper sized conductor to be used for 10 amp 120 landscape transformers with the distance of the run being 2000 feet.
Click to expand...
Are the transformers located at the end of the 2000 ft run or are they located at various locations along the run? If at various locations you have a different problem.
 
roger

roger

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Staff member
Location
Fl
Occupation
Retired Electrician
Re: Voltage drop and landscapers

Run, a ring circuit with your #4 and you will be fine. :D

Roger
 
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bennie

Esteemed Member
Re: Voltage drop and landscapers

This sounds like an irrigation system. Is this for a golf course?
 
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djtazjr

Member
Re: Voltage drop and landscapers

The system is on a country club and its the lights along the walls that keeps the cars out of sight for the place.

There are three transformers for the low voltage lights.

Further? :)
 
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bennie

Esteemed Member
Re: Voltage drop and landscapers

Is the distance of 2000 feet the one way length?

If so, for 4000 feet of wire I would look seriously into high voltage street lighting systems.
 
iwire

iwire

Moderator
Staff member
Location
Massachusetts
Re: Voltage drop and landscapers

Having the load spread out means you could calculate the voltage drop for each section.

This would allow dropping some wire sizes as you reduce the load,

Something like this

Panel to first transformer 1/0

First to second transformer 4 AWG

Second to third transformer 8 AWG

To really figure this you need to know each of the distances.

Feeding these as a multiwire branch circuit would help particular if 3 phase is available.
 
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djtazjr

Member
Re: Voltage drop and landscapers

We are not completely finished yet, but I will let everyone know what the lights look like when the project is finished.
;)
 
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