UL 347:2016 pdf free download – STANDARD FOR SAFETY Medium-Voltage AC Contactors, Controllers, and Control Centers.
4.102 Rated duties
[Vacant]
4.103 Rated making and breaking capacities
A contactor shall be capable of making and breaking the maximum current at which the overload relays alone cause current interruption (take -over current) The rating is determined by the make and break capacity test described in Clause 6.102.
4.104 Utilization category
[Vacant]
4.105 Mechanical endurance (standard and optional)
With respect to its endurance against mechanical wear, a contactor or starter is characterized by the number of noload operating cycles (i.e.. without current on the main contacts) that can be made before it becomes necessary to replace any parts.
The minimum number of operations for the required standard rating is 10 000 and shall be verified in accordance with the test described in Clause 6.101.2.
An optional rating above 10 000 may be provided. The preferred optional ratings, expressed in millions of operations, are 0.03, 0.1, 0.3, 1 and 3.
4.106 Electrical endurance
[Vacant]
4.107 Coordination with medium-voltage fuses
Class E2 controllers are characterized by the type, ratings, and characteristics of the power fuses. Current-limiting fuses, to be used to provide overcurrent delineation between the contactor(s) and medium-voltage fuses, shall be coordinated with the contactor. The contactor interrupting rating and breaking time shall be coordinated with the medium-voltage fuses such that the contactor does not attempt to interrupt currents above its breaking capacity.
The medium-voltage fuses shall preferably be located on the supply side of the controller, and shall have a short-circuit breaking capacity not less than the prospective current (symmetrical) under short-circuit conditions at its location.
The medium-voltage fuses shall not operate in place of the contactor for currents up to the maximum overload levels in normal service (including stalled current of the motor).
For additional coordination information, refer to Clauses 4.201 and 4.202.
4.108 Types and characteristics of automatic change-over devices and automatic acceleration
control devices
(Vacant)
4.109 Types and characteristics of autotransformers or reactors
Autotransformers or reactors shall be characterized by:
a) the supply voltage:
b) the number of taps available for adjusting the starting torque and current:
C) the rated starting voltage (see Clauses 4.2.102 and 4.2.103);
d) the current they can carry for a specified duration:
e) the rated starting duty (see Clause 4.204 and 4.204.1); and
f) the method of cooling (e.g., free air, forced air, oil immersion).
The autotransformer or reactor may be either built into the controller or provided separately.
4.110 Types and characteristics of the starting resistors for rheostatic motor starters
(Vacant)
4.111 Characteristics dependent on starter type
[Vacant]
4.112 Rated capacitive switching currents
A capacitive switching current rating is optional. The rating of a switching device for capacitive currer switching shall include one or both of the following, where applicable:
a) Rated single capacitor bank breaking current and inrush making current.
b) Rated back-to-back capacitor bank breaking current and inrush making current. The values of rated capacitive switching currents shall be given by the manufacturer.