UL 2231-1:2002 pdf download Personnel Protection Systems for Electric Vehicle (EV) Supply Circuits: General Requirements
1 Scope
1.1 These requirements cover devices and systems intended for use in accordance with the NationalElectrical Code (NEC), ANSI/NFPA 70, Article 625, to reduce the risk of electric shock to the user fromaccessible parts,in grounded or isolated circuits for charging electric vehicles. These circuits are externato or on-board the vehicle.
1.2 The devices and systems covered by these requirements must be compatible with the designs ofcharging systems and vehicles where use is intended and shall be rated accordingly. To assurecompatibility, the features contained in 1.3 – 1.5 are required of the charging system, the vehicle, or both
1.3 The type of vehicle covered by these requirements, including all accessible conductive parts on thevehicle, have one or more of the following:
a) Provision for the connection of an equipment grounding conductor during battery chargingunless the vehicle has a system of reinforced or double insulation or all of the circuitry on thevehicle is electrically isolated from the supply circuit;
b) Provision for the connection of ground-monitoring conductors, where required:
c) Reinforced insulation or be double-insulated from the supply circuit; or
d)No direct connection between current carrying conductors and the vehicle chassis
1.4 These requirements cover devices and systems where the grounding path impedance of the chargingsystem to the vehicle is less than or equal to the impedance of the ungrounded conductor or conductors
1.5 These requirements cover devices and systems where a continuous current less than 70 mA RMS isavailable from any accessible part of the charging system.
1.6 Devices covered by these requirements are intended to interrupt the electric circuit to the load when:
a)A fault current to ground exceeds some predetermined value that is less than that requiredto operate the overcurrent protective device of the supply circuit,
b)The grounding path becomes open-circuited or becomes an excessively high impedance, or
c)A path to ground is detected on an isolated (ungrounded) system.
1.7 These devices and systems are intended to be applied on electrical systems or include derivedsystems that are:
a) Either end-grounded or centrally grounded when the operating voltage is 150 Vrms or less.
b) Centrally grounded when the operating voltage is greater than 150 Vrms, or
c) Isolated (ungrounded).
1.8 Charging circuit interrupting devices covered by these requirements are investigated for their abilityto provide protection based on:
a) The type of current (60 Hz AC, DC, a combination of AC and DC, or AC at frequenciesgreater than 60 Hz) present in the circuit to be protected, and
b) Voltage.
1.9 These requirements do not cover ground-fault circuit-interrupters (GFCls) intended for use aspersonnel protection in accordance with the National Electrical Code on grounded 120 Vrms to ground.60 Hz circuits. Such devices are covered under the Standard for Ground-Fault Circuit-Interrupters. UL943
1.10 This standard includes the Scope, Glossary, and Description of Requirements, including therequired features of protection systems. The Standard for Personnel Protection Systems for ElectricVehicle (EV) Supply Circuits: Particular Requirements for Protection Devices for Use in ChargingSystems, UL 2231-2, contains the Performance and Construction requirements for protective devices thatwould become a part of a charging system.
2 Glossary
2.1 For the purposes of this standard, the following definitions apply.
2.2 ACCESSIBLE PART – A part so located that it is capable of being contacted by a person, eitherdirectly or by means of an accessibility probe.
2.3 AUTOMATIC RECLOSURE – The act of charging circuit interrupting device reseting itself afterbeing tripped.
2.4 BASIC INSULATION – The insulation required for the proper functioning of a device, and for basicprotection against electrical hazard.
2.5 CENTRALLY LOCATED GROUND – A system connection to ground so located that the maximumvoltage to ground on all of the system conductors is minimized
2.6 CENTRALLY LOCATED GROUND WITH IMPEDANCE LIMITATION – A centrally located groundsystem with a grounding path impedance that is not higher than that value which limits the voltage to150 Vrms on accessible parts with respect to earth at the site of the fault during a low-impedanceground-fault.
2.7 CHARGING CIRCUIT INTERRUPTING DEVICE (CCID) – A device that continuously monitors thedifferential current among all of the current-carrying line conductors in a grounded system and rapidlyinterrupts the circuit under conditions where the differential current exceeds the rated Measurementindication Unit (MIU) value of a charging circuit interrupting device, The device is identified by the lettersCCID followed by the diferential trip current rating of either 5 or 20 indicating the tripping rating in MIU.See also 5.1.
2.8 CORD-AND-PLUG CONNECTED – A device that connects to a supply circuit by way of a flexiblecord terminating in an attachment plug.