Okay, let's break this down to ensure we're compliant with the NEC (National Electrical Code) and prioritizing safety.

Here's the analysis and the required action


The Problem: Greenfield (Flexible Metal Conduit - FMC): Greenfield (FMC) is not inherently a good grounding path, especially for high fault currents. It can have high impedance, especially with loose connections. This is why the NEC has specific rules about its use as an equipment grounding conductor (EGC).2. NEC Requirements for FMC as an EGC (Generally Not Allowed for this Application): FMC can be used as an EGC under specific conditions (NEC 250.118). The key issue here is the size and the fact that you already have a separate EGC. Exception to Using FMC as an EGC

Typically not met in your scenario.3.

Your Situation: Separate 10 AWG EGC You're running a 10 AWG EGC inside the conduit. This is the correct approach for a 60 amp circuit.4. Bonding Bushings and Greenfield Connection



Requirement

The general rule (NEC 250.92) requires that metallic conduit be bonded to ensure electrical continuity. Since you are transitioning from rigid (EMT) to flexible (FMC) and then to a non-metallic enclosure (the EV Charger), you need to ensure proper bonding to maintain a reliable path to ground.

The answer to your question



Yes, you need a bonding bushing at the point where the greenfield connects to the plastic EV charger housing.Explanation

The purpose of the bonding bushing is to create a secure, low-impedance path to ground for the greenfield. Even though you have the 10 AWG EGC running inside, the greenfield itself needs to be bonded to prevent it from becoming energized in the event of a fault external to the insulated conductors.Because you are transitioning from metal to non metal conduit, a bonding bushing and jumper is required. The jumper should connect to the ground bar in the EV Charger and provide an effective ground fault current path.

What to Do


Install a Bonding Bushing on the Greenfield Connector inside the EV Charger

Choose a bonding bushing that is properly sized for the knockout and the greenfield connector.2.

Bonding Jumper

Attach a bonding jumper (insulated wire, often green) from the bonding bushing to the ground bar or designated grounding point inside the EV charger enclosure. The bonding jumper should be sized according to NEC 250.102(C)(1) and Table 250.122 based on the overcurrent protective device (60 amps in your case). A #10 AWG conductor is adequate.
3.

Ensure Tight Connections

Make sure all connections are clean and tight.

Important Considerations



Torque

Use a torque screwdriver/wrench to tighten all bonding screws and connectors to the manufacturer's specified torque. Loose connections are a common cause of problems.

Inspection

Have your work inspected by a qualified electrical inspector to ensure compliance with local codes and the NEC.

In summary, even with the 10 AWG EGC running inside, the greenfield needs to be properly bonded at the EV charger to maintain a safe and code-compliant installation. A bonding bushing and jumper will provide a reliable grounding path for the metal conduit. Flag for review