Okay, let's break down the situation and address the potential code issues.

Your Proposal

You have an existing 6-2 MC cable. You plan to install a 60A 240V GFCI breaker disconnect where the MC cable terminates. You plan to bond the neutral bus to the enclosure at the disconnect. You plan to feed a 4-wire GFCI-protected EV outlet from this disconnect.

Potential Code Issues & Explanations


Existing 6-2 MC Cable Ampacity



Issue

The primary concern is whether the existing 6-2 MC cable is rated for 60 amps. The ampacity of conductors is determined by NEC 310.15. For copper conductors, 6 AWG is typically rated for 55 amps in most common insulation types (THHN, THWN, etc.) when installed in accordance with Table 310.
16. You cannot protect a conductor with an overcurrent device (breaker) larger than its ampacity (NEC 240.4).

Code Reference



NEC 240.4(D) Protection of Flexible Cords and Fixture Wires. This section outlines specific situations where smaller conductors are permitted to be protected by larger OCPDs (overcurrent protective devices), which does not include branch circuits such as this. NEC 310.15 (Ampacity) and relevant tables (e.g., Table 310.16) for determining conductor ampacity. NEC 110.3(B) Installation and Use. Equipment shall be installed and used in accordance with any instructions included in the listing or labeling. (MC cable will have a listing) Solution

You

must verify the ampacity rating of the existing 6-2 MC cable. Check the markings on the cable itself. If it's rated for 60 amps, you might be okay (assuming all other conditions are met). However, if it's rated for less than 60 amps (most likely 55 amps), you cannot use a 60A breaker to protect it. You would need to either: Reduce the breaker size to match or be less than the cable's ampacity. (e.g., use a 50A breaker instead) Replace the cable with one rated for 60 amps. De-rate the EVSE's output current to be within the limits of the existing cable.2. GFCI Protection for EV Chargers (NEC 625.54) Requirement

NEC 625.54 requires GFCI protection for all outlets installed for EV charging of electric vehicles.

Your Plan

Your plan to use a GFCI breaker disconnect is compliant with 625.54.
3.

Bonding the Neutral Bus to the Enclosure at the Disconnect



Issue

This is likely a

violation. You only bond the neutral to the enclosure at the service equipment (where power enters the building). Downstream of the service equipment (in a subpanel or disconnect), the neutral must be isolated from the enclosure. Connecting them together creates a parallel neutral path, which is dangerous. Code Reference



NEC 250.32(A) General. For a building or structure supplied by a feeder(like your disconnect), an equipment grounding conductor (EGC) shall be run with the feeder conductors to the building or structure and connected to a grounding electrode system. The equipment grounding conductor shall be used for grounding non–current-carrying metal parts of equipment, raceways, and other enclosures. The equipment grounding conductor shall be bonded to the grounding electrode(s).

NEC 250.24(A)(5) Load-Side Grounding Connections. On the load side of the service point, the grounding electrode conductor shall not be connected to the grounded conductor (neutral).

NEC 250.6(D) Load-Side Equipment. Equipment grounding conductors shall be installed with circuit conductors to the load-side equipment supplied by any feeder. The equipment grounding conductor shall not be used as the sole grounding path.

Solution



Do NOT bond the neutral bus to the enclosure at the disconnect. The disconnect enclosure should be grounded by a separate equipment grounding conductor (EGC) that runs back to the main service panel and is connected to the grounding electrode system. This means the 6-2 MC cable might not be sufficient; you'll need a 4-wire circuit (hot, hot, neutral, ground).4.

MC Cable and Grounding



Issue

Older MC cable might not have an insulated grounding conductor.

Code Reference

NEC 250.118

Solution

You need to confirm that your MC cable has an insulated equipment grounding conductor. If the cable does not have an insulated grounding conductor, it may not be an acceptable grounding path.5.

4-Wire Circuit to EV Outlet

Requirement

NEC 625.13 requires a separate equipment grounding conductor for EVSE's.

Solution

Ensure you are running a 4-wire circuit to your EVSE outlet, with two hots, a neutral, and a dedicated ground.

Summary & Recommendations


Verify the 6-2 MC cable's ampacity. If it's less than 60 amps, reduce the breaker size or replace the cable.2.

Do NOT bond the neutral to the enclosure at the disconnect. Run a separate EGC (equipment grounding conductor) from the disconnect back to the main panel's ground bus.3.

Use a 4-wire circuit to the EV outlet.4.

Confirm that your MC cable has an insulated equipment grounding conductor.5.

Ensure the GFCI breaker disconnect is properly rated for the EV charger's load. EV chargers are considered continuous loads (NEC 625.22), so you must size the breaker for 125% of the charger's continuous load.
6.

Follow all manufacturer's instructions for the GFCI breaker, disconnect, and EV charger.

Important Note: This information is for general guidance only and should not be considered a substitute for professional electrical advice. Always consult with a qualified electrician to ensure your installation complies with all applicable codes and is safe. Electrical work can be dangerous if not performed correctly. Flag for review