Outside Disconnect

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Cody K

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Texas
We have a new installation of an industrial plant where the MCC is going to be 60 ft away from the transformer poles. The service will be 2000 amp 3 phase 480v and will connect to the MCC via cable tray. The MCC has a 2000amp main circuit breaker that is listed as service equipment.

My question is do we need a disconnect at the pole? Fused or non-fused? I believe we do not but I am getting feedback from others that disagree.

Thanks
 
I might be mis-reading this situation, but I agree with you. Am I correct in understanding that the utility owns the transformers, the poles, and the wires from that point up to your MCC? If so, then those wires are service conductors. There is a need for a service disconnect, but the main breaker at the MCC can perform that function. As to the question of protecting the service conductors from overcurrent, or providing a means of disconnecting them from the transformers, that is the utility?s problem. And the utility is not constrained by NEC rules.
 
Thanks for your repy Charlie. So what your saying, as far as you know, there is nothing NEC related that would require us to install an extra disconnect, whether it be fused our non fused. However, the power company could request us to do so.
 
I think it really depends on who owns the wires from the transformer to the MCC. If you own them, and if you put a disconnect at the pole, that becomes your service point. You would need to do the N-G bond at that location, and remove that bond at the MCC. But if the utility owns them, then the service point is at the MCC, and you don't get to install anything at the pole (i.e., you can't tamper with the utility wires and equipment).
 
Who is "the PC"? If that is the local authority, I would start by asking them to cite the source of the requirement (i.e., NEC article).
 
charlie b said:
Who is "the PC"? If that is the local authority, I would start by asking them to cite the source of the requirement (i.e., NEC article).
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PC "power company" is supposed to give us a reply hopefully soon on whether or not we need a disconnect. The problem is a 2000 amp non fused manual switch is over 10k, not to mention the labor to install. If it is not required then I dont see a problem with using the existing MCB in the MCC.
 
The MCC runs the entire length of the building against the wall. The building is about 18ft long and 12ft wide. The MCB is located where the conductors enter the building.
 
Cody K said:
PC "power company" is supposed to give us a reply hopefully soon on whether or not we need a disconnect. The problem is a 2000 amp non fused manual switch is over 10k, not to mention the labor to install. If it is not required then I dont see a problem with using the existing MCB in the MCC.
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If the POCO wants you to put a disco that close to the pole and it's going to cost you that much why not ask them how much would cost for them to put fuses right at the transformer output on the pole. Just a thought.
 
acrwc10 said:
If the POCO wants you to put a disco that close to the pole and it's going to cost you that much why not ask them how much would cost for them to put fuses right at the transformer output on the pole. Just a thought.
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Good idea... I will definitely ask
 
Talk to the local AHJ (Authority Having Jurisdiction [Local Inspector]). Some require it, and some don't. Also, was this mentioned in the bid package presented to you prior to making your bid?
 
hdpeng said:
Talk to the local AHJ (Authority Having Jurisdiction [Local Inspector]). Some require it, and some don't. Also, was this mentioned in the bid package presented to you prior to making your bid?
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Sorry, it took so long. This installation is a large refridgeration plant we are doing for our own company. We included a large 2000A service disconnect near the poles in our budjet which was over $10k (for non fused). To this day I still cannot get a response from the POCO.

Do you all have any suggestions for locating the AHJ when they are in a different town? I mean... this facility is over 6 hours from where I live.
 
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