UL 1066:2016 pdf free download – STANDARD FOR SAFETY Low-Voltage AC and DC Power Circuit Breakers Used in Enclosures.
SUPPLEMENT SC – INTEGRALLY MOUNTED, REMOTELY OPERATED RACKING MECHANISMS
FOR USE WITH LOW VOLTAGE POWER CIRCUIT BREAKERS
INTRODUCTION
SC1 Scope
SC1 .1 These requirements cover integrally mounted, remotely operated racking mechanisms intended to mechanically move (rack) a withdrawable circuit breaker into or out of the connected position, while allowing the operator to stand a distance from the equipment.
Sd .2 The requirements do not cover externally mounted remote racking devices.
Sd .3 These requirements cover control powered, cord-connected, and battery powered remotely operated racking mechanisms with a supply voltage rating of 600 V or less.
Sd .4 These requirements cover equipment intended for use in ordinary locations in accordance with the National Electrical Code, ANSI/NFPA 70.
CONSTRUCTION
SC2 General
SC2.1 Remotely operated racking mechanisms shall comply with the interlock requirements of IEEE
C37.20.1.
SC2.2 Remotely operated racking mechanisms shall demonstrate the proper sequential operation for drawout circuit breakers as outlined for Mechanical Endurance Tests in IEEE C37.20.1 (see cycles of operation in IEEE C37.20.1).
SC2.3 Remotely operated racking mechanisms shall have provision for manual operation and shall be located so that when in use the wiring space and live parts are not exposed. Means shall be provided to prevent remote operation from functioning during manual operation.
SC2.4 A remotely operated racking mechanism shall be provided with an acceptable means for grounding all exposed accessible metal parts.
SC2.5 If any part of the remotely operated racking mechanism, when installed, interferes with the intended venting of the circuit breaker or reduces the distance to grounded dead metal, the overload, endurance, and short-circuit interrupting tests are to be performed on the circuit breaker with the remotely operated racking mechanism installed.
SC2.6 The time to complete each cycle shall be specified by the manufacturer in the instructions. See 5C8.6.
SC2.7 A means shall be provided to indicate to the operator the position of the circuit breaker and that the operating command has been completed successfully.
SC3 Control Powered Racking Mechanisms
SC3.1 Racking mechanisms that are powered by the control power of the circuit breaker or switchgear in which the circuit breaker is installed shall comply with SC3.2 through SC3.4.
SC3.2 The control power connection shall be automatically engaged when the circuit breaker is inserted into the disconnect position.
SC3.3 Grounding continuity shall be established when the power connection is engaged.
SC3.4 Control powered remote racking mechanisms shall be marked in accordance with SC8.4.
SC4 Cord-Connected Racking Mechanisms
SC4.1 Racking mechanisms that are cord-connected to the power supply shall be provided with a hard-service or junior hard-service flexible cord, such as Type S, SJ, or the equivalent, that is rated for the temperature and voltage involved or with a rated inlet (motor attachment plug).
SC4.2 The cord ampacity, as specified in Table SC1, shall not be less than the ampacity required for the racking mechanism.