500ft 240v 50amp branch circuit feed

[simonjerry1807]

Hey all,
Hoping I can get some assistance or verification. I have a 500ft underground run from source to a sub panel with direct burial 1/0 al conductors. I have done my calculations and determined the conductor at said length is sufficient for 30amps at end.connection to sub panel. My question is if I parallel this run would my available amperage at the sub panel now be 60amps ?
Please advise.

 

[tom baker]

How can you get 60 amps with a 50 amp feeder breaker?
What type of load is it?
No neutral needed?

 

[simonjerry1807]

It's direct burial cable 1/0 3 wire with a ground
Contains black ,red, white and aluminum ground
Through calculation I was able to determine that wire at the end of a 500ft run can supply.30amps staying under 3% voltage drop. My question is if another multi conductor cable is ran and installed in parallel would that double the amps available at the sub panel I am installing. If one run good for 30 amps 2 run in parallel 60amps?

 

[tom baker]

How do you get 60 amps from a 50 breaker, and how will you connect 2 runs of 1/0 to a 50 breaker?

 

[simonjerry1807]

The conductors would be spliced in either Polaris or split bolt then connected to breaker

 

[augie47]

Short answer to your question: Yes, good for 60 amps +

 

[curt swartz]

What size is the equipment grounding conductor?

 

[Dennis Alwon]

The equivalent of 2 1/0 aluminum conductors is 105600 x2 = 211,200 cm

Do you calculation from that....

 

[Dennis Alwon]

What size is the equipment grounding conductor?

That's a trap....haha

 

[petersonra]

As others alluded to, you would not meet the requirements for the size of the equipment grounding conductor.

 

[winnie]

If we assume a 60A supply breaker and Al conductors, then the baseline conductor size is 4 AWG.

If the conductor is then increased in size to 2x 1/0 AWG for reasons of voltage drop, then a similar increase in EGC is required.

The baseline Al EGC for a 60A breaker is #8, which would need to be increased in size to 2x #4 or approximately #1. (I'm not going to do the detailed calc unless the OP has odd cables. )

If the OP's cables have #1 EGCs then this installation might be kosher. I suspect that the EGCs are smaller than this.

Jon

 

[simonjerry1807]

1/0 AL 600VUD TX BERGEN/YS/USE-2 1000 FT | Southwire

Aluminum Conductors. Cross-linked Polyethylene (XLP) Insulation.

www.southwire.com

This is the cable
It carries no ground but is categorized for secondary distribution and service feed.
Once terminated at sub panel ground rod driven and ground wire sized appropriately bonded at panel

I assumed it it came with a ground wire in jacket but it does not

Thanks for pointing out the ground I missed the fact that it did not come with one

 

[curt swartz]

1/0 AL 600VUD TX BERGEN/YS/USE-2 1000 FT | Southwire

Aluminum Conductors. Cross-linked Polyethylene (XLP) Insulation.

www.southwire.com

This is the cable
It carries no ground but is categorized for secondary distribution and service feed.
Once terminated at sub panel ground rod driven and ground wire sized appropriately bonded at panel

I assumed it it came with a ground wire in jacket but it does not

Thanks for pointing out the ground I missed the fact that it did not come with one

I hope you are not suggesting to not include an EGC with this feeder and using a rod as the ground.

 

[wwhitney]

Thanks for pointing out the ground I missed the fact that it did not come with one

You could get the 4/C 1/0 Al version, and your EGC in each cable would only be slightly oversized.

Cheers, Wayne

 

[simonjerry1807]

I hope you are not suggesting to not include an EGC with this feeder and using a rod as the ground.

The cable is designed as it is ungrounded and for direct burial.
How would you include egc? It's not going in conduit
Panel is effectively grounded with groundrod and grounding conductor. Cable is ul listed and designed for use as secondary, feeder cable

 

[curt swartz]

The cable is designed as it is ungrounded and for direct burial.
How would you include egc? It's not going in conduit
Panel is effectively grounded with groundrod and grounding conductor. Cable is ul listed and designed for use as secondary, feeder cable

What you are proposing does not comply with the NEC and is extremely dangerous. A ground rod does not provide a fault clearing path. You are going to get someone killed.

 

[winnie]

The installation you are planning is not code compliant.

If you use a ground rod connected to the panel ground bus, then while the panel will be 'grounded' it will not be bonded, and you won't have a fault current path. This is extremely dangerous because ground faults can leave exposed metal energized rather than tripping a breaker.

The other option is to bond the panel neutral and ground together, like a service. Treating an outside feeder like a service is safer than the unbonded installation, and was safe enough to be allowed in the past. It is not allowed under current code.

Since you are planning to direct bury 'cables' which are really conductors bundled together without an external sheath, I don't see a problem with just adding the required EGC as single conductor direct bury wire in the same trench.

Jon

 

[simonjerry1807]

What you are proposing does not comply with the NEC and is extremely dangerous. A ground rod does not provide a fault clearing path. You are going to get someone killed.

Curt it is not my plan to install and create a hazard. I have not done an Installation of this nature before and seeking advice. I thankyou for your input and appreciate your input. I am planning this install and it is my intent to do it safely and per code.

 

[roger]

Curt it is not my plan to install and create a hazard. I have not done an Installation of this nature before and seeking advice. I thankyou for your input and appreciate your input. I am planning this install and it is my intent to do it safely and per code.

You will need a cable with four conductors one of which will be the EGC and if you are going to go with parallel sets the EGC in a cable assembly may not meet the required size. A GEC may be required for your installation but as Curt and Jon pointed out, earth does not take the place of the EGC.

 

[roger]

BTW, the title of your thread states "branch circuit feed" but you are talking about a "feeder"