EVSE Rating and Load Management Controls
NEC 625.42 EV charging is a continuous load, so service and feeder sizing follows the EVSE's full product rating unless an EMS or an adjustable-setting EVSE legally caps the demand.
Q1 NEC 625.42
Under 625.42, how must service and feeder conductors supplying EVSE be sized by default?
- A At the noncontinuous portion of the load only, per general branch-circuit rules
- B In accordance with the EVSE product ratings, since the charging load is continuous
- C At the EVSE's rating with no continuous-load adjustment, since EVSE is exempt from the continuous-load rule
- D At whatever value an EMS assigns, even if no EMS is installed
Show answer & explanation
Correct: B — In accordance with the EVSE product ratings, since the charging load is continuous
625.42 states EV charging loads are continuous loads and that service and feeder shall be sized per the EVSE's product ratings, unless the overall rating is limited by controls under 625.42(A) or (B). There's no exemption from continuous-load treatment, and an EMS cap only applies when an EMS is actually installed.
Overall EVSE cable length limit and how to measure it
NEC 625.17(C) EVSE cord or cable usable length is capped at 25 ft unless a listed cable management system is part of the equipment, and where you measure from depends on portable vs. fastened-in-place.
Q2 NEC 625.17(C)
An installer wants to use an EVSE cord longer than 7.5 m (25 ft). Under what condition is this permitted?
- A If the EVSE includes a cable management system that is part of the listed equipment
- B If the cord is run through rigid metal conduit for its full length
- C Only if the vehicle connector is rated for outdoor use
- D Only if the branch circuit supplying the EVSE is on a GFCI breaker
Show answer & explanation
Correct: A — If the EVSE includes a cable management system that is part of the listed equipment
625.17(C) permits exceeding the 25 ft usable length cap only when the electric vehicle supply equipment is equipped with a cable management system that is part of the listed EVSE. GFCI protection, connector rating, and conduit routing don't affect this specific length exception.
EVSE power-supply cord requirements (type, ampacity, length)
NEC 625.17(A) A cord-connected EVSE's supply cord must use a listed cord type rated for wet/damp locations, carry adequate ampacity, and stay within strict length limits tied to where the personnel protection device sits.
Q3 NEC 625.17(A)
A fastened-in-place EVSE has its personnel protection system interrupting device located inside the equipment enclosure. What is the maximum permitted length of the power-supply cord?
- A 1.8 m (6 ft)
- B 4.6 m (15 ft)
- C 3.0 m (10 ft)
- D 300 mm (12 in.)
Show answer & explanation
Correct: A — 1.8 m (6 ft)
Per 625.17(A)(3)(a)(ii), when the interrupting device is inside the enclosure of fastened-in-place equipment, the cord is limited to 1.8 m (6 ft), and the equipment must be mounted so the cord cannot touch the floor when connected. The 12 in. limit applies only to portable equipment under the same enclosure-mounted condition, and the 15 ft limit applies only when the interrupter is at the plug or within the first 12 in. of cord.
Bidirectional/Interactive EVSE and Island Mode
NEC 625.48 EVSE that exports power back to a building or the grid must be listed for that specific interactive purpose, and its equipment article (702 or 705) still applies.
Q4 NEC 625.48
An EVSE unit includes a power export function and is intended to back up a dwelling's loads during a utility outage. Per 625.48, what must be true of this equipment before it can be used this way?
- A It must be listed and marked as suitable for use as an interactive system
- B It must be limited to a single dedicated 125-volt receptacle outlet
- C It must be field-evaluated on-site instead of factory listed
- D It only needs a standard EVSE listing, since export is a built-in EVSE feature
Show answer & explanation
Correct: A — It must be listed and marked as suitable for use as an interactive system
625.48 requires EVSE or WPTE with a power export function used as an interactive system (optional standby, power production, or bidirectional feed) to be listed and marked as suitable for that purpose. A standard EVSE listing does not cover export/interactive functions, and 625.48 doesn't require field evaluation or limit export to a receptacle unless that's actually the export method used.
EVSE Mounting Location and Height
NEC 625.50 The EVSE coupling means must sit at least 18 in. above the floor indoors or 24 in. above grade outdoors, unless it's listed for a different location or is a portable unit.
Q5 NEC 625.50 Code lookup
A commercial EVSE unit is being installed outdoors in a parking structure. The electrician needs to confirm the minimum height above grade at which the coupling means (connector) must be stored or located. Which section specifies this requirement?
- A 625.60(B)
- B 625.56
- C 625.44(C)
- D 625.50
Show answer & explanation
Correct: D — 625.50
625.50 sets the mounting/coupling height requirement (18 in. indoors, 24 in. outdoors above grade). 625.44(C) covers connection methods for fixed-in-place equipment, not mounting height, and 625.56/625.60(B) address receptacle enclosures and ratings, not coupling location.
Disconnecting Means for Larger EVSE/WPTE
NEC 625.43 EVSE or WPTE over 60 A or over 150 volts to ground needs a lockable-open disconnect in a readily accessible spot, with a plaque if it's not on the equipment.
Q6 NEC 625.43
A WPTE installation operates at 200 volts to ground. Per 625.43, what is required?
- A A disconnecting means only if the equipment also exceeds 60 amperes
- B No disconnecting means, since WPTE is exempt from 625.43
- C A dedicated disconnecting means in a readily accessible location
- D A disconnecting means located within sight of the equipment only
Show answer & explanation
Correct: C — A dedicated disconnecting means in a readily accessible location
625.43 requires a disconnecting means whenever EVSE or WPTE exceeds 60 amperes OR 150 volts to ground — the conditions are independent, not both-required. At 200 volts to ground, the threshold is met regardless of amperage, so a readily accessible disconnect is required; there's no within-sight-only limitation in this section.
Connecting EVSE/WPTE to Premises Wiring (Cord vs. Fixed)
NEC 625.44 EVSE/WPTE connects to premises wiring as portable or fastened-in-place equipment only through the specific nonlocking receptacle types listed in 625.44 — anything else must be permanently hardwired fixed-in-place.
Q7 NEC 625.44
A wall-mounted EV charger is fastened in place, and the installer wants a cord-and-plug connection instead of hardwiring. Which receptacle type is NOT a valid option under 625.44(B)?
- A A nonlocking, 2-pole, 3-wire, 60-volt dc receptacle rated 20 amperes
- B A nonlocking, 2-pole, 3-wire, 125-volt receptacle rated up to 50 amperes
- C A locking, 2-pole, 3-wire, 250-volt receptacle rated 50 amperes
- D A nonlocking, 3-pole, 4-wire, 125/250-volt receptacle rated 50 amperes
Show answer & explanation
Correct: C — A locking, 2-pole, 3-wire, 250-volt receptacle rated 50 amperes
625.44(B) only permits nonlocking grounding-type receptacles for fastened-in-place equipment. A locking receptacle isn't one of the listed methods, so it isn't a valid cord-and-plug option — the equipment would need hardwiring or one of the nonlocking configurations instead.
Ventilation Requirements for Indoor EV Charging
NEC 625.52 Ventilation is only required if the charging equipment is listed as needing it indoors — and when it's required, the ventilation fan must be electrically interlocked to run for the whole charging cycle.
Q8 NEC 625.52 Code lookup
A shop plans to install listed EVSE that requires mechanical ventilation to charge vehicles indoors. Which section specifies the minimum ventilation rate for a given number of vehicles when the supply voltage and current match the standard table entries?
- A 625.52(B)(3)
- B 625.52(A)
- C 625.52(B)(2)
- D 625.52(B)(1)
Show answer & explanation
Correct: D — 625.52(B)(1)
625.52(B)(1) is the section hosting the tables of minimum ventilation (m3/min or cfm) for listed supply voltages and currents. 625.52(B)(2) only applies when the voltage/current combination isn't covered by those tables, and 625.52(B)(3) covers engineered systems designed by a qualified person, not the standard tabulated values.
Overcurrent Protection Sizing for EVSE/WPTE
NEC 625.41 Size the overcurrent device at 125% of continuous EVSE/WPTE load, plus 100% of any noncontinuous load sharing that feeder.
Q9 NEC 625.41
Per 625.41, overcurrent protection for a branch circuit supplying EVSE must be sized using which method?
- A 150% of the noncontinuous load only
- B 100% of the maximum load with no continuous-duty adjustment
- C 125% of the maximum continuous load of the equipment
- D 80% of the branch-circuit conductor ampacity
Show answer & explanation
Correct: C — 125% of the maximum continuous load of the equipment
625.41 requires overcurrent protection sized for continuous duty at not less than 125% of the maximum load. Skipping the continuous-duty adjustment, using the 80%-of-ampacity conductor-sizing concept, or applying 150% to a noncontinuous figure all misstate the actual rule.
AC Receptacle Outlets for Vehicle Power Export (EVPE)
NEC 625.60 An EVPE receptacle must be listed, capped at 250V/50A single phase, backed by integral overcurrent protection, and GFCI-protected with a readily accessible reset.
Q10 NEC 625.60
An electric vehicle is equipped with an AC receptacle for exporting power to off-board equipment. Per 625.60(B), what is the maximum permitted rating for that receptacle?
- A 120 volts maximum, single phase, 20 amperes maximum
- B 600 volts maximum, three phase, 50 amperes maximum
- C 250 volts maximum, single phase, 60 amperes maximum
- D 250 volts maximum, single phase, 50 amperes maximum
Show answer & explanation
Correct: D — 250 volts maximum, single phase, 50 amperes maximum
625.60(B) caps EVPE receptacle outlets at 250 volts maximum, single phase, 50 amperes maximum. The 120V/20A option is far more restrictive than the code requires, the 600V three-phase option exceeds both the voltage cap and the single-phase requirement, and 60 amperes exceeds the 50-ampere ceiling.
GFCI Protection and Weatherproof Enclosures for EV Receptacles
NEC 625.54 Every EV charging receptacle needs GFCI protection, and any receptacle in a wet location needs a weatherproof enclosure rated for use with the plug inserted.
Q11 NEC 625.54
Per 625.54, which receptacles installed for electric vehicle charging require ground-fault circuit-interrupter protection for personnel?
- A All receptacles installed for EV charging connection
- B Only receptacles on individual branch circuits over 150 volts to ground
- C Only receptacles installed outdoors
- D Only receptacles rated above 20 amperes
Show answer & explanation
Correct: A — All receptacles installed for EV charging connection
625.54 requires GFCI protection for personnel on all receptacles installed for the connection of electric vehicle charging, with no carve-out by amperage, location, or voltage. The amperage, outdoor-only, and voltage-based limits are plausible but do not appear in 625.54.
WPTE control box mounting and configuration
NEC 625.102(B) The WPTE control box must sit above minimum height thresholds — 450 mm (18 in.) indoors, 600 mm (24 in.) outdoors — and be mounted only as a pedestal, wall/pole, building/structure, or raised concrete pad.
Q12 NEC 625.102(B)
An outdoor WPTE control box is being mounted on a pole. What is the minimum height above grade required by 625.102(B)?
- A 900 mm (36 in.)
- B 600 mm (24 in.)
- C 450 mm (18 in.)
- D 300 mm (12 in.)
Show answer & explanation
Correct: B — 600 mm (24 in.)
625.102(B) sets the outdoor minimum at 600 mm (24 in.) above grade level. The 450 mm (18 in.) figure is the indoor-above-floor threshold, not the outdoor one, and 900 mm and 300 mm don't appear in this section at all.