Okay, let's break down the requirements and best practices for terminating 8/2 MC cable into a plastic EV charger enclosure.

The Short Answer

Yes, you can terminate 8/2 MC into a plastic EV charger enclosure. However, grounding practices are absolutely critical and require careful attention. Using a bonding bushing is generally not required.

The Long Answer, with Considerations


Code Compliance (NEC)

This is paramount. I can't provide definitive code advice (consult a licensed electrician for that), but I can highlight the relevant areas:

314.3 Nonmetallic Boxes

This covers the use of nonmetallic boxes (enclosures) and any limitations.

250 (Grounding and Bonding)

The most important section. This deals with ensuring a safe and effective ground fault current path.

330 (Metal-Clad Cable: Type MC)

This covers the permitted uses and installation requirements for MC cable.

625 (Electric Vehicle Charging System)

Specific requirements for EV charger installations.2.

MC Cable and Grounding



8/2 MC Typically contains 2 insulated current carrying conductors and one bare or green insulated equipment grounding conductor. The Importance of the Ground Wire

The bare or green insulated grounding conductor in the MC cable is your primary means of providing a low-impedance fault current path. This is what protects people from shock if there's a fault within the charger.3.

Terminating into the Plastic Enclosure



No Metal-to-Metal Contact

Because the enclosure is plastic, you cannot rely on the enclosure to provide a ground. The plastic doesn't conduct electricity.

Direct Ground Connection

Connect the ground wire (bare or green insulated) in the MC cable directly to the grounding terminal block or screw inside the EV charger enclosure. This is the most important step.

Strain Relief

Use an appropriate strain relief connector (e.g., a cable clamp) where the MC cable enters the plastic enclosure. This prevents tension on the wires inside the enclosure. Ensure the strain relief is listed for use with MC cable. Use a connector that is listed for Non-Metallic use.4.

Bonding Bushing and MC Jacket



Not Typically Required for Plastic Enclosures

Bonding bushings are generally used in metallic enclosures to bond the MC cable's metal jacket to the enclosure, creating a continuous ground path through the metal enclosure. Since your enclosure is plastic, a bonding bushing serves no purpose for grounding.5.

Removing the NEMA 14-50P (Plug)



Hardwiring

Since you plan to remove the plug and hardwire the charger, ensure the charger is rated and designed for hardwired installation, consult with an electrician and follow the charger manufacturer's instructions.

Overcurrent Protection

Make sure the circuit breaker protecting the circuit is sized appropriately for the charger's requirements.

Step-by-Step Procedure (General Guidance - CONSULT A QUALIFIED ELECTRICIAN)


Turn Off Power

Completely de-energize the circuit at the breaker panel. Double-check with a voltage tester.2.

Prepare the MC Cable

Carefully strip back the outer jacket of the MC cable, exposing the insulated conductors and the ground wire. Be careful not to damage the insulation on the wires.3.

Install Strain Relief

Install the appropriate MC cable strain relief connector into the enclosure knockout. Tighten it securely.4.

Insert Cable into Enclosure

Feed the MC cable through the strain relief connector into the enclosure.5.

Connect the Ground Wire

Connect the ground wire (bare or green insulated) from the MC cable directly to the grounding terminal inside the charger enclosure. Ensure the connection is tight and secure.6.

Connect the Phase Conductors

Connect the two insulated conductors to the appropriate terminals on the EV charger (L1 and L2). Follow the charger manufacturer's instructions for wiring.7.

Secure Strain Relief

Tighten the strain relief connector to properly grip the MC cable.8.

Verify Connections

Double-check all connections to ensure they are tight and secure.9.

Close the Enclosure

Properly close and secure the EV charger enclosure.10.

Turn on Power

Turn the circuit breaker back on and test the EV charger.

Important Warnings/Cautions



Incorrect wiring can lead to electric shock, fire, or damage to the EV charger. If you are not completely comfortable with electrical work, hire a licensed electrician. Always follow the EV charger manufacturer's instructions for installation and wiring. Comply with all applicable local and national electrical codes. Proper grounding is critical for safety. Never assume anything. Always test and verify. Double Check Torque Settings

Many electrical failures occur from not tightening connections to the proper torque setting.

In summary, you can run 8/2 MC to a plastic EV charger enclosure, but focus on providing a direct and secure ground connection from the MC cable's ground wire to the charger's grounding terminal. Bonding the MC jacket to a plastic enclosure with a bonding bushing is not effective. Always prioritize safety and consult a qualified electrician if you have any doubts. Flag for review