Can I do a supply side tap with a breaker enclosure to feed a 60 amp EV charger?

A supply side tap, also called a line side tap, connects the EV charger feeder ahead of the main service disconnect rather than to a breaker in the panel. It sidesteps the 120 percent busbar rule in 705.12(B)(3)(2) entirely, because the charger is no longer a load on the busbar. The Code permits it, but there are specific conditions.

The sections that allow it

Section 230.82 lists equipment permitted to be connected on the supply side of the service disconnecting means. Item 3 covers meter disconnect switches, and other items cover taps used for specific purposes. Section 230.40 Exception 2 permits a building with more than one occupancy to have one set of service entrance conductors for each service or for each set of service entrance conductors. Section 230.71(B) in the 2023 NEC allows up to six service disconnects grouped in one location, or in separate enclosures grouped together, and 230.72 requires them to be grouped.

In practice you add a second service disconnect. The tap lands on the line side lugs of the meter main or in a listed splice compartment, runs to a fused disconnect or a breaker enclosure with a main breaker, and from there feeds the EV charger. That new enclosure is a service disconnect, not a subpanel, and it is counted against the six disconnect limit.

What that means for the wiring

Because the new enclosure is a service disconnect, the neutral is bonded to the enclosure per 250.24(C) and 250.28. You install the main bonding jumper. You do not isolate the neutral the way you would in a subpanel. A grounding electrode conductor connection is required per 250.24(A), which normally means tying the new enclosure into the existing grounding electrode system with a conductor sized from Table 250.66.

The tap conductors are service entrance conductors, so they are unprotected until they reach the new disconnect. Section 230.70(A)(1) requires the service disconnect to be installed at a readily accessible location either outside the building or inside nearest the point of entrance of the service conductors. Keep the unprotected run as short as possible. Section 230.6 covers when conductors are considered outside the building, such as under 2 inches of concrete or encased in 2 inches of concrete or brick.

Utility and equipment listing

Section 110.3(B) requires the meter main to be used within its listing. Many meter mains do not have listed provisions for a second set of line side conductors, and doubling up on the line lugs violates 110.14(A) unless the terminal is identified for more than one conductor. Listed line side tap kits and polaris style insulated multitap connectors listed for service entrance use solve this. Most utilities also require notification or a permit before anyone opens the meter can, and many require the utility to pull the meter for the work.

The charger side

Section 625.41 requires EV supply equipment rated more than 16 amperes or more than 120 volts to be supplied by an individual branch circuit with no other outlets. Section 625.42 treats EVSE as a continuous load, so a 60 ampere circuit supports a 48 ampere charger. Conductor size is 6 AWG copper at 75 degrees C from Table 310.16 with a 60 ampere breaker, and 10 AWG copper equipment grounding conductor from Table 250.122.

Field takeaway

The supply side tap is legal under 230.82 and the 230.71(B) six disconnect allowance. Treat the new enclosure as a service disconnect: bond the neutral, tie in a grounding electrode conductor, keep the unprotected tap short and readily accessible, and use a listed tap connector rather than doubling up lugs. Call the utility before opening the meter.