EV chargers

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hhsting

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I have power cabinet for EV chargers which convert AC to DC installed 80 feet away from the dispensers. Please see attached. The dispensers are separate piece of equipment and the power cabinet is separate piece of equipment by same manufacturer.

The DC cable between the dispensers and the power cabinet go underground 80 feet. Please see below

Does one need external breaker or overcurrent protection for DC conductors at the power cabinet according to NEC 2017?


84190c3777e7f7fb3c9ffff4cd96e0da.jpg
 
was that not covered in this thread ??

EV chargers have you seen this type?

I am really stuck on this would really appreciate all your help. Previous post dealt with issues of 625.43. However this post its about protecting DC conductor between dispensers and power cabinet. The designer tells me the power cabinets have no internal breaker. Only software that detects 350A...
forums.mikeholt.com
 
hhsting said:
I have power cabinet for EV chargers which convert AC to DC installed 80 feet away from the dispensers. Please see attached. The dispensers are separate piece of equipment and the power cabinet is separate piece of equipment by same manufacturer.

The DC cable between the dispensers and the power cabinet go underground 80 feet. Please see below

Does one need external breaker or overcurrent protection for DC conductors at the power cabinet according to NEC 2017?


84190c3777e7f7fb3c9ffff4cd96e0da.jpg
Click to expand...
IMO, you need overcurrent protection. Where it is located and how it is done is not specified in the code.
 
augie47 said:
was that not covered in this thread ??

EV chargers have you seen this type?

I am really stuck on this would really appreciate all your help. Previous post dealt with issues of 625.43. However this post its about protecting DC conductor between dispensers and power cabinet. The designer tells me the power cabinets have no internal breaker. Only software that detects 350A...
forums.mikeholt.com
Click to expand...

No actually this is different type and does NOT have internal fuses in power cabinet instead they have computer software in power cabinet which they say protects the cable
 
The manufacturer has provided a method of overcurrent protection suiatable to the listing agency. I see no cause for concern.
 
I would think the question hinges on whether (a) both the dispenser and the power cabinet are listed as a single piece of equipment with field installed conductors subject to the rules in the listing and instructions or (b) the dispenser and the power cabinet are listed separately. In (b) I would think the NEC would cover the field installed wiring between the two enclosures, while in (a) I would think it falls under the UL listing and outside of the NEC.

Cheers, Wayne
 
wwhitney said:
I would think the question hinges on whether (a) both the dispenser and the power cabinet are listed as a single piece of equipment with field installed conductors subject to the rules in the listing and instructions or (b) the dispenser and the power cabinet are listed separately. In (b) I would think the NEC would cover the field installed wiring between the two enclosures, while in (a) I would think it falls under the UL listing and outside of the NEC.

Cheers, Wayne
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I would agree. The installs I have seen fall under your option (a) and if they are under (b) and there is some type over-current protection then the conductors would be the prime concern and that was addressed in his previous thread.
Perhaps a case of tilting at windmills :)
 
wwhitney said:
I would think the question hinges on whether (a) both the dispenser and the power cabinet are listed as a single piece of equipment with field installed conductors subject to the rules in the listing and instructions or (b) the dispenser and the power cabinet are listed separately. In (b) I would think the NEC would cover the field installed wiring between the two enclosures, while in (a) I would think it falls under the UL listing and outside of the NEC.

Cheers, Wayne
Click to expand...

Let me ask you because i dont understand the above. Lets say you have listed panelboard and listed water heater. Mets say they are from same listing UL.

The water heater instructions shows cable size. The contractor is going to install that cable based on manufacturer instruction.

Does not the cable need breaker and NEC 2017 apply? So then how come on condition A above NEC does not apply?
 
hhsting said:
Let me ask you because i dont understand the above. Lets say you have listed panelboard and listed water heater. Mets say they are from same listing UL.

The water heater instructions shows cable size. The contractor is going to install that cable based on manufacturer instruction.

Does not the cable need breaker and NEC 2017 apply? So then how come on condition A above NEC does not apply?
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Both need an OCPD, but the equipment itself can provide the required overcurrent protection for the conductors between the two pieces of equipment. The code required OCDP, but does not require a specific device to provide that OCPD. As long as the first piece of equipment provides the required protection, you are good. Now that means you have to dig into the manufacturer's instructions, however I expect that the design engineer has already done and the results are reflected in the design.
 
don_resqcapt19 said:
Both need an OCPD, but the equipment itself can provide the required overcurrent protection for the conductors between the two pieces of equipment. The code required OCDP, but does not require a specific device to provide that OCPD. As long as the first piece of equipment provides the required protection, you are good. Now that means you have to dig into the manufacturer's instructions, however I expect that the design engineer has already done and the results are reflected in the design.
Click to expand...

Computer software as an OCPD is acceptable?


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hhsting said:
Let me ask you because i dont understand the above. Lets say you have listed panelboard and listed water heater.
Click to expand...
If you had a fancy water heater that came with its own control cabinet (which was actually just a panelboard with some other circuitry in it), and the tank and the control cabinet were listed together as a single piece of equipment, and the instructions told you what field wiring to use between them, then the NEC stops at the connection of the branch circuit to the control cabinet. At least by default; for some equipment the NEC calls out specific requirements beyond the outlet.

Cheers, Wayne
 
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wwhitney said:
If you had a fancy water heater that came with its own control cabinet (which was actually just a panelboard with some other circuitry in it), and the tank and the control cabinet were listed together as a single piece of equipment, and the instructions told you what field wiring to use between them, then the NEC stops at the connection of the branch circuit to the control cabinet. At least by default; for some equipment the NEC calls out specific requirements beyond the outlet.

Cheers, Wayne
Click to expand...

Which section says that in nec 2017?


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A lot of equipmemt is pre-wired by the manufacturer and consists of more than one component. The components are shipped, set and interconnection made, often with manufacturered supplied materials and/or instructions for interconnections. The listing often covers the entire equipment and a lot of jurisdictions rule that it falls under 90.7 and the equipment is checked for damage and torqued connections.
 
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