UL Standard for Safety Requirements for Electrical Equipment for Measurement, Control and Laboratory Use – Part 2-032: Particular Requirements for Hand-Held and Hand-Manipulated Current Sensors for Electrical Test and Measurement
|Publication Date:||10 January 2020|
Scope and object
Equipment included in scope
This part of IEC 61010 specifies safety requirements for HAND-HELD and hand-manipulated current sensors described below.
These current sensors are for measuring, detecting or injecting current, or indicating current waveforms on circuits without physically opening the current path of the circuit being measured. They can be stand-alone current sensors or accessories to other equipment or parts of combined equipment. These include measurement circuits which are part of electrical test and measurement equipment, laboratory equipment, or process control equipment. These current sensors and circuits need additional protective means between the current sensor, the circuit and an OPERATOR.
NOTE 1 Combined equipment is equipment that is electrically connected to a current sensor by means of a permanent connection which can be detached only by the use of a TOOL.
NOTE 2 Some current sensors are also known as current clamps, CLAMP MULTIMETERS and current probes.
Current sensors are hand-manipulated before and/or after a test or measurement, but do not necessarily need to be HAND-HELD during the test or measurement. Current sensors used as FIXED EQUIPMENT are not within the scope of this document.
The following types of current sensors are covered:
a) Type A: a current sensor designed to be applied to or removed from HAZARDOUS LIVE UNINSULATED CONDUCTORS. Type A current sensors have defined HAND-HELD or hand-manipulated parts providing protection against electric shock from the conductor being measured, and also have protection against short-circuits between wires and between busbars during clamping.
b) Type B: a current sensor which has protection against short-circuits between wires or busbars during clamping but without defined HAND-HELD or hand-manipulated parts which provide protection against electric shock during clamping. Additional protective means are necessary to avoid electric shock from HAZARDOUS LIVE conductors which cannot be de-energised during application or removal of the current sensor.
EXAMPLE 1 Flexible current sensors.
c) Type C: a current sensor without protection against short-circuits between wires or busbars during clamping. Type C current sensors are intended to be applied to or removed from HAZARDOUS LIVE UNINSULATED CONDUCTORS or from non-limited-energy circuit conductors only when they are de-energised.
EXAMPLE 2 Split-core transducers.
d) Type D: a current sensor designed to be applied to or removed from insulated conductors or from limited-energy circuit conductors.
EXAMPLE 3 Current probes for oscilloscopes and earth leakage current detectors.
All current sensors can also be used with insulated conductors. In this case, HAZARDS are limited to acceptable levels by the insulation of the conductors.
Additional requirements for CLAMP MULTIMETERS are given in Annex EE.
Aspects included in scope
Requirements for protection against HAZARDS resulting from NORMAL USE and REASONABLY FORESEEABLE MISUSE of measuring circuits are given in Clause 101.
Requirements for prevention of HAZARD from arc flash and short-circuits are given in Clause 102.
Requirements for reliance on the displayed value of CLAMP MULTIMETERS are given in Clause EE.5.