View Full Version : horse barn subpanel
VM
November 12th, 2002, 05:02 PM
Hello everyone, this is my first post on this forum so bear with me.
I would like to add electrical service to my four stall horse barn. Looking back at how many circuits I have added over time to the houses that I have owned, I want to make sure that I install a large enough panel, thus subpanel feeder, to handle all my future needs. Initially I intend to have outlets for heated buckets near each stall, outside outlets for heating troughs, general use outlets, and lighting (probably three 500W lights). The thing that makes this interesting is the fact that the subpanel feeder will be 350 ft long. I have two 200 Amp mains in the house. For the moment let's assume I want to run a 60A 220V capacity run to the subpanel. Some questions that come to mind:
1. What gauge wire is needed for the service?
2. How many lines are run? That is, Can I run just the two legs of the main and neutral, or do I need to run a ground as well?
3. I assume that a new ground needs to be driven in the barn?
4. If a ground is not run with the subfeeder, I believe the neutral and newly installed ground buses need to be bonded?
5. If a ground is run with the feeder, what gets bonded together?
These questions can be hypothetical or reality, I just do not know at this point. If someone has suggestions on what I should install, I am open to this as well.
What is fact is I just ran water to the outside of the barn and the trench is still open. The trench is 36" deep and about 300 ft long. I plan to fill it to 18", then lay the eletrical line in. I am going to install 1.5" or 2" conduit, depends on the gauge wire that I need to run.
I hope that I have not been to winded, but on the other hand I hope that I have given enough background info.
Wgoodrich
November 12th, 2002, 07:17 PM
First I would like to bring to your attention that buildings with animals are controlled by an article for agricultural buildings. Agricultural buildings do not require GFI protection except outside receptacles such as water trough heaters or any other outside receptacles used. Then animal excrement is a concern due to the acidic atmosphere created due to that animal excrement. Normal NMB Romex cable will become brittle and the plastic covering of that Romex will chip off like egg shells when left exposed in this animal housing type building. All receptalces in the area of the animals require weather proof boxes and cover plates. Most often nonmetallic sheathed cable that is corrosion resistan such as UF cable is used entering the device boxes [receptacle and switches] from the bottom of the boxes so that if this building is washed down inside any water entering the boxes would drain out the bottom where the wires are entering the box. If this UF Cable is entered in the top then water would run down those cables directed right inside the box. This does not happen if this UF cable enters the bottom of the boxes. YOu may use PVC conduit but remember to consider the rule requiring expansion joints in longer runs of PVC conduit that can not expand long ways. That area inside a tack room or a building that is with a wall from ceiling to floor separating that building into two parts that makes a dual occupancy building such as that horse barn and a repair garage then that garage area not exposed to the animals would not be required to be corrosion resistant. Any panel inside a tack room or garage area that is separated from that horse excrement may be a normal panel box however that area exposed to the horses would require a weatherproof panel. Also a biggy to consider when dealing with animals is that animals are more suseptable to electrical shock. Article 547 explains about an expotential plane created by a more elaborite grounidng system including wire mesh in the concrete and the grounidng electrode conductor [that conductor between the service panel and any ground rod or other grounding electrode system must be a green insulated grounding electrode conductor. Normally grounding electrode conductors are fine bare or insulated solid or standed. Agricultural buildings require green grounding electrode conductors.
YOU SAID;
I would like to add electrical service to my four stall horse barn. Looking back at how many circuits I have added over time to the houses that I have owned, I want to make sure that I install a large enough panel, thus subpanel feeder, to handle all my future needs. Initially I intend to have outlets for heated buckets near each stall, outside outlets for heating troughs, general use outlets, and lighting (probably three 500W lights). The thing that makes this interesting is the fact that the subpanel feeder will be 350 ft long. I have two 200 Amp mains in the house. For the moment let's assume I want to run a 60A 220V capacity run to the subpanel. Some questions that come to mind:
REPLY;
I woiuld guess those bucket heaters to be 600 t0 1000 watts each. I would guess the water trough heaters to be 1000 to 1250 watt heaters. I would be VERY CAREFUL as to placement of those 500 watt incandescent bulbs that would set anything on fire if it touches that bulb if that is what you are using. YOu might want to check into what is called low bay light fixtures that are ballasted and resistant to temperature change and cost savings also to run with better lighting and less fire risk.
If we added the wattage of your heaters and say 2000 watts for lighting then you would have a total load of about 35 amps. YOu are saying 350 feet that would lead me to suggest that a 60 amp load at 350 feet using copper 6 awg feeder single phase you would experience a 8.59% voltage drop or 20.62 volts dropped. If you increase that wire to 3 awg copper of 2 awg aluminum then that 60 amp load would be within recommended voltage drop suggested maximums. If we calculated a 60 amp load as you suggested then you owuld have about enough to add an electric water heater. If it were me I would install 1/0 copper and a 100 amp breaker panel with a 100 amp breaker in your house. This would give you future for growth such as a second barn or added loads. I suspect if you stayed with a 60 amp panel the cost factor going to 100 would be minimumal if noticed and you would be short changing your barn area for any future growth concerns. Just my opinion.
YOU SAID;
1. What gauge wire is needed for the service?
2. How many lines are run? That is, Can I run just the two legs of the main and neutral, or do I need to run a ground as well?
REPLY;
If there is no noncurrent carrying metallic paths connecting the two buildings then two hots and a neutral can do fine.
YOU SAID;
3. I assume that a new ground needs to be driven in the barn?
REPLY;
Yes either way 3 wire or 4 wire with a grounding conductor either way you must install a grounding electrode normally a ground rod. Don't forget to install an insulated grounding electrode conductor to meet the NEC requirements of Article 547 due to concerns of animal shock being more critical concerning animals.
YOU SAID;
4. If a ground is not run with the subfeeder, I believe the neutral and newly installed ground buses need to be bonded?
REPLY;
Yes
YOU SAID;
5. If a ground is run with the feeder, what gets bonded together?
REPLY;
If an equipment grounding conductor is requried or voluntarily installed with the feeder then you must isolate the neutral bar in that barn panel from the equipment grounding conductor and from the metal casing of the panel. The neutral conductor must be isolated anywhere in that barn.
YOU SAID;
These questions can be hypothetical or reality, I just do not know at this point. If someone has suggestions on what I should install, I am open to this as well.
What is fact is I just ran water to the outside of the barn and the trench is still open. The trench is 36" deep and about 300 ft long. I plan to fill it to 18", then lay the eletrical line in. I am going to install 1.5" or 2" conduit, depends on the gauge wire that I need to run.
REPLY;
YOu must bury your electrical feeder a minimum of 24" deep. The distance from the water line [plastic I am guessing] is not needed separated more than about 6 to 8 inches.
I also suggest that if you direct bury your wires or water pipe then you back fill your water pipe and your electric line with sand leaving about 6" of sand all around these water lines and feeder. This will protect you from a rock causing damage to either that would require you to replace either if damaged. Remember a pinhole punched through the insulatoin of a direct buried cable will eat that cable like battery acid in no time. PVC conduit is a fine idea but still be concerned about some sand as a back fill for your water pipe. Then use THWN copper feeders inside the conduit. The bigger conduit would not cost that much and would definitly save a bunch of digging if you need to upgrade the feeder and service to that barn in the future.
Good Luck and hope some of the above is of some help to you.
Wg
VM
November 13th, 2002, 01:39 PM
Warren,
Thank you for all the excellent advice. 1/0 copper is going to be expensive.
Thanks again and keep up the great work!!!
Wgoodrich
November 13th, 2002, 02:22 PM
YOu can probably save money now on that feeder by reducing size to a smaller feeder conductor but with the distance you are going with that feeder then add in the distance to end of line for your branch circuit I would predict that although you saved money on the initial investment you will be paying more monthly on your electric bill that will deplete that savings over a short period of time. Then that motor you add in that barn at end of circuit when the life expectancy is shortened due excessive heat becuase of low voltage the repairs on that motor will probably look back at the initial savings of the reduced sized feeder wondering how much you could have saved if you have put the 1/0 wire in instead of trying to save money on original installation.
Just my thoughts
Wg
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