EV charger NEC 2017 questions

[hhsting]

Please see attached sketches. I have 1600A switchboard 277/480V 1600A with main of 1600A. Have 300A breakers which feed power cabinets 150kW. The power cabinets then feed from DC dispensers EV charger.

The switchboard is in concrete pad outside. The sketch shows floor plan of switchboard and the power cabinets. Distance between is 4 feet

The dispensers are on parking lot.

Questions:

1. Nec 2017 section 625.43 requires disconnect. So both the power unit cabinets and the dispensers require disconnect? Or one of them or none of them?

2. Nec 2017 section 625.44(b) requires receptacles. It just says equipment does this mean dispensers and power units require receptacles?

3. Nec 2017 section 625.40 require outlet. I looked at definition of outlet but am confused does this mean each dispensers require receptacle or not?

4. Does the dispensers EV chargers have to be grounded with ground rods? Where is it in NEC 2017?

 

[wwhitney]

Partial answers:

1) There will need to be 4 disconnects. These EV chargers are "Level 3" DC chargers at high power, which I am not so familiar with the wiring of. If the Power Cabinet is part of the EV charger, then the disconnect should be upstream of the Power Cabinet. If the Power Cabinet is vanilla AC distribution equipment, then the disconnect should be between the Power Cabinet and EV Charger.

2) A receptacle makes zero sense for this application, and 625.44(b) only applies to "Stationary equipment intended to be fastened in place in such a way as to permit ready removal for interchange, facilitation of maintenance or repair, or repositioning." This equipment is not designed for "permit ready removal for interchange, facilitation of maintenance or repair, or repositioning," so no receptacle is required.

3) The point of 625.40 is just that each EV charger gets a branch circuit that serves only it and no other loads. It's not necessary to get into the nuisances of "outlet" for this, but briefly: generally utilization equipment is not part of the premises wiring; different materials and regulations apply to each category. So the outlet is just the demarcation point between the utilization equipment and the premises wiring. If there's a receptacle, that's the outlet; the cord and plug connected equipment is utilization equipment, but the receptacle and upstream are premises wiring. Even when there's no receptacle, there's an outlet; for hardwired equipment, it would be where the building wiring connects to the equipment wiring, often in a wiring compartment on the equipment.

Cheers, Wayne

 

[Charged]

Please see attached sketches. I have 1600A switchboard 277/480V 1600A with main of 1600A. Have 300A breakers which feed power cabinets 150kW. The power cabinets then feed from DC dispensers EV charger.

The switchboard is in concrete pad outside. The sketch shows floor plan of switchboard and the power cabinets. Distance between is 4 feet

The dispensers are on parking lot.

Questions:

1. Nec 2017 section 625.43 requires disconnect. So both the power unit cabinets and the dispensers require disconnect? Or one of them or none of them?

2. Nec 2017 section 625.44(b) requires receptacles. It just says equipment does this mean dispensers and power units require receptacles?

3. Nec 2017 section 625.40 require outlet. I looked at definition of outlet but am confused does this mean each dispensers require receptacle or not?

4. Does the dispensers EV chargers have to be grounded with ground rods? Where is it in NEC 2017?

I don’t believe you need any disconnects if your switchboard is accessible and the breakers can be locked in the open position.
The DC run from the power cabinet to the dispenser should be provided with OCP in the power cabinet. The manufacturers have been getting better at showing what that is on spec sheets and installation manuals. I’ve done a lot of similar projects. I’ve never had an ahj ask for a service disconnect for the dispenser.
You have a pretty typical set up for DC fast charging in a open lot, I don’t see you needing any additional disconnects. I always put a ground rod but technically I think a equipment ground is the only thing needed. It’s like a light pole, whether it’s a separate structure, those discussions. The last manufacturer I did a design for recommended them in the installation instructions so that made me feel better for adding them on most projects anyways.

 

[hhsting]

I don’t believe you need any disconnects if your switchboard is accessible and the breakers can be locked in the open position.
The DC run from the power cabinet to the dispenser should be provided with OCP in the power cabinet. The manufacturers have been getting better at showing what that is on spec sheets and installation manuals. I’ve done a lot of similar projects. I’ve never had an ahj ask for a service disconnect for the dispenser.
You have a pretty typical set up for DC fast charging in a open lot, I don’t see you needing any additional disconnects. I always put a ground rod but technically I think a equipment ground is the only thing needed. It’s like a light pole, whether it’s a separate structure, those discussions. The last manufacturer I did a design for recommended them in the installation instructions so that made me feel better for adding them on most projects anyways.

I see that between switchboard and power cabinet if breakers are lockable and in readily accessible as called in NEC 2017 section 625.43 one might not need disco for power cabinet.

The power cabinet takes AC and converts to DC which then feed dispensers.

However would the power cabinet have breakers internal that are lockable? Also the farthest distance from dispenser to the power cabinet is 85 feet and all from the plans open parking lot and on grass concrete pad their is switchboard power cabinets. Would breakers in power cabinet be readily accessible location? If not then disco would be required for the dispensers. What have you noticed do ones you encountered have them lockable? What is your opinion on 85 feet distance and readily accessible?

 

[hhsting]

Partial answers:

1) There will need to be 4 disconnects. These EV chargers are "Level 3" DC chargers at high power, which I am not so familiar with the wiring of. If the Power Cabinet is part of the EV charger, then the disconnect should be upstream of the Power Cabinet. If the Power Cabinet is vanilla AC distribution equipment, then the disconnect should be between the Power Cabinet and EV Charger.

2) A receptacle makes zero sense for this application, and 625.44(b) only applies to "Stationary equipment intended to be fastened in place in such a way as to permit ready removal for interchange, facilitation of maintenance or repair, or repositioning." This equipment is not designed for "permit ready removal for interchange, facilitation of maintenance or repair, or repositioning," so no receptacle is required.

3) The point of 625.40 is just that each EV charger gets a branch circuit that serves only it and no other loads. It's not necessary to get into the nuisances of "outlet" for this, but briefly: generally utilization equipment is not part of the premises wiring; different materials and regulations apply to each category. So the outlet is just the demarcation point between the utilization equipment and the premises wiring. If there's a receptacle, that's the outlet; the cord and plug connected equipment is utilization equipment, but the receptacle and upstream are premises wiring. Even when there's no receptacle, there's an outlet; for hardwired equipment, it would be where the building wiring connects to the equipment wiring, often in a wiring compartment on the equipment.

Cheers, Wayne

The power distribution cabinet takes AC converts to DC which feed dispensers. The power distribution cabinet has breakers DC side. However the farthest distance from dispenser to the power cabinet is 85 feet. Dispensers are all on open parking lot and 85 feet from the on grass area with concrete pad is the switchboard and power cabinet. Would NEC 2017 section 625.43 require 4 disocs?

 

[hhsting]

Power cabinet manufacturer is Signet and model is HPC 175K