UL 1008A-2017 pdf download

UL 1008A-2017 pdf download.Transfer Switch Equipment, Over 1000 Volts.
16.3 Location and protection of transfer control circuits
16.3.1 When a transfer switch is marked for service equipment use,and the control circuit is connectedon the line side of the service disconnecting means, the control circuit shall have short-circuit protectionand a disconnecting means suitable for the available current of the supply.
16.3.2 Control circuits may extend from a transfer switch to an external engine-generator set,when amarking indicates that the control circuit wiring is to be in conduit. See 56.7.
16.3.3 Other control circuits that are depended upon for the proper operation of a transfer switch shall belocated wholly within the transfer switch enclosure and shall not have overload protective devicesconnected in them, but may have short-circuit and ground-fault protection. In a transfer switch consistingof multiple vertical sections, the control circuits may be in any vertical section of a continuous lineup ofsections.
16.3.4 When an electrical motor on a transfer switch drive mechanism is provided with overloadprotection,the motor shall be protected against locked-rotor burnout only.
16.3.5 To be in compliance with 16.3.4,the overload protector shall not open during the MechanicalEndurance Tests,40.
16.4 Transfer switches for emergency use
16.4.1 The operating mechanism and control circuit shall be such that the load cannot remainsimultaneously disconnected from both the normal and alternate supplies when either or both supplies areavailable with voltage and frequency sufficient to permit proper operation. When intended for use withparalleled engine generator sets,transfer to the generator source or sources may be inhibited untilsufficient power for the connected load is available. See 56.4.5.
16.4.2 The mechanism of a transfer switch intended for use with paralleled engine-generator sets asind icated in 16.4.1 may be arranged to disconnect from the alternate source(generators) in the event ofshutdown of one or more of the paralleled engine-generator sets.
16.4.3 The operating mechanism of the normal and emergency contacts of an automatic transfer switchfor use in emergency systems shall be electrically operated.
16.4.4 The normal and emergency contacts of an automatic transfer switch intended for use inemergency systems shall be mechanically held in a closed position.
16.4.5 At least one manually operated dead front test switch shall be provided to simulate loss of thenormal supply, or provision shall be made for the connection of a remote test switch or switches.
16.4.6 Circuits for the remote test switches required in 16.4.5 for automatic transfer switches shall bearranged so that shorting or opening of the circuit or test switch does not reduce the possibility of transferto the alternate source in the event of loss of the normal source.
C3.2 All tests shall be conducted on enclosed samples.One sample shall complete the overload,temperature，endurance，and dielectric voltage-withstand tests,in that order.Alternatively，thetemperature test may be perfomed following the overload and endurance tests. A previously untestedsample may be used for withstand and closing tests. When multiple specific load uses are specified,additional samples may be used.
c4 Normal Operation
C4.1 Bypass switches shall be capable of operating acceptably for all conditions of their intendedperformance.
C4.2 A bypass switch shall be operated in each intended position and the effectiveness of all interlocksshall be determined by attempting to place the mechanism in positions intended to be prevented by theinterlock.
c5 Overload
C5.1 A bypass switch employing load-break contacts shall perform acceptably when subjected to anoverload test in accordance with Overload Test,37.
c6 Temperature
C6.1 A bypass switch shall perform acceptably when subjected to a temperature test in accordance withTemperature Test,39.
C6.2 lf the configuration and ampacity of the bus bars and switching components used in various modesdiffer, more than one temperature test could be required.
C7 Endurance
C7.1 A bypass switch shall pertorm acceptably when subjected to an endurance test in accordance withMechanical Endurance Test,4O.
c8 Dielectric Voltage-Withstand
C8.1 A bypass switch shall perform acceptably when subjected to the dielectric voltage-withstand test inaccordance with Dielectric voltage-Withstand Test,41.
c9 Short-Circuit withstand
C9.1 Both the bypass contacts and the isolating means contacts shall comply with the short-circuitwithstand test requirements specified in 44.
c10 Short-Time Current Rating Test(Optional)
C10.1 A bypass switch shall comply with the requirements in Short-Time Current Rating Test, 46, andDielectric voltage-Withstand Test,41.
c11 Short-Circuit Closing
C11.1 A bypass switch employing load-break contacts shall perform acceptably when subjected to ashort-circuit closing test in accordance with Closing, 45.