IEC 60947-4-2:2011 pdf free download – Low-voltage switchgear and controlgear
1 Scope
This standard applies to a.c. semiconductor motor controllers and starters,which may includea series mechanical switching device, intended to be connected to circuits, the rated voltageof which does not exceed 1 000 v a.c.
This standard characterizes a.c. semiconductor motor controllers and starters with andwithout bypass means.
AC semiconductor motor controllers and starters dealt with in this standard are not normallydesigned to interrupt short-circuit currents. Therefore，suitable short-circuit protection (see8.2.5) should form part of the installation, but not necessarily of the a.c. semiconductor motorcontroller or starter.
In this context, this standard gives requirements for a.c.semiconductor motor controllers andstarters associated with separate short-circuit protective devices.
This standard does not apply to continuous operation of a.c. motors at motor speeds other than the normal speed;
semiconductorequipment， includingsemiconductor contactors(see 2.2.13 ofIEC60947-1:2007) controlling non-motor loads;
– electronic a.c. power controllers covered by IEC 60146 series.
Contactors，overload relays and control circuit devices used in a.c. semiconductor motorcontrollers and starters should comply with the requirements of their relevant productstandard. Where mechanical switching devices are used, they should meet the requirementsof their own lEC product standard, and the additional requirements of this standard.
The object of this standard is to state as follows:
– the characteristics of a.c. semiconductor motor controllers and starters and associated
equipment;
– the conditions with which a.c. semiconductor motor controllers and starters comply withreference to
a) their operation and behaviour;
b) their dielectric properties;
c) the degrees of protection provided by their enclosures where applicable;d) their construction;
– the tests intended for confirming that these conditions have been met, and the methods tobe adopted for these tests;
– the information to be given with the equipment, or in the manufacturer’s literature.
NOTE Forthe purpose ofthis standard, the term”controller” may be used instead of”a.c. semiconductor motor controller”.
2Normative references
The following referenced documents are indispensable for the application of this document.For dated references,only the edition cited applies.For undated references, the latest editionof the referenced document (including any amendments) applies.
IEC 60034-1:2010，Rotating electrical machines – Part 1: Rating and performance
IEC 60085:2007,Electrical insulation – Thermal evaluation and designation
lEC 60269-1:2006,Low-voltage fuses – Part 1: General requirementsAmendment 1 (2009)
IEC 60410:1973,Sampling plans and procedures for inspection by attributes
IEC 60664(all parts), Insulation coordination for equipment within low-voltage systems
IEC 60947-1:2007,Low-voltage switchgear and controlgear – Part 1: General rules
IEC 61000-4 (all parts)，Electromagnetic compatibility(EMC) – Part 4: Testing andmeasurement techniques
CISPR 11:2009，Industrial, scientific and medical equipment – Radio-frequency disturbancecharacteristics – Limits and methods of measurement
Amendment 1 (2010)
3.3.2
a.c. semiconductor motor controller
semiconductor switching device that provides the starting function for an a.c. motor and anOFF-state
NOTE 1 Because dangerous levels of leakage currents can exist in a semiconductor motor controller in the OFF-state, the load terminals should be considered as live parts at all times.
NOTE 2 In a circuit where the current passes through zero (alternately or otherwise), the effect of “not making”the current following such a zero value is equivalent to breaking the current.
3.3.3 semiconductor motor controller (form 1)
a.c. semiconductor motor controller，in which the starting function may comprise any startingmethod specified by the manufacturer， and that provides control functions which may includeany combination of manoeuvring, controlled acceleration, running or controlled deceleration ofan a.c. motor.A FULL-ON state may also be provided
NOTE See Figure 1 and Table 1.
3.3.4 semiconductor soft-start motor controller (form 2)
special form of a.c. semiconductor motor controller, in which the starting function is limited toa voltage and/or current ramp which may include controlled acceleration， and where theadditional control function is limited to providing FULL-ON
NOTE See Figure 1 and Table 1.