UL 60950-23-2016 pdf download

UL 60950-23-2016 pdf download.lnformation Technology Equipment – Safety – Part 23: Large Data Storage Equipment.
Opening of the interlocked access door into any compartment of a WORK CELL containing hazardous moving parts, or an access door between a compartment containing hazardous moving parts and one that has been disabled, shall automatically remove drive power from those moving parts arid fully stop them without the need of software control within 3 5.
Except as permitted in 5,1 it shall not be possible to start or restart the system until all relevant access doors are closed and latched.
Where it is possible to enter a WORK CELl. completely, an automatically activated mechanical interlock shall be provided so that the door cannot be closed inadvertently, it this closure would allow the system to be restarted. It shall be possible to open any door from inside the WORK CELL without the use of a key or Toot. The means of opening the door from inside the wo CELL shall be readily identifiable and visible, whether the door is open or dosed, irrespective of the operating status of the equipment.
Compliance is checked by inspection.
5 Interlock override
5.1 General
If t is necessary for a SERVEE PERSON to override a SAFETY WTTRLOCI( for access to a WORK CELl, or compartment, an override system complying with 2.8.6 of IEC 60950-1 shall be provided. In addition, when an override system is used, an emergency stop system shall be provided in accordance with Clause 6. and shall comply with the operational endurance requirements of Clause 7.
Compliance is checked by inspection.
5.2 VIsual Indicator
A set of two or more bright flashing indicators complying with IEC 60073 shall operate under the fdlowing conditions:
a) for a wo cau. or compartment that can be entered completely, to indicate the
equipment is being restored to normal operation and motion is pending, or
b) for any equipment. when the interlock is overridden and drive power is available to hazardous moving parts.
The indicators shell be readily visible at any point within the WORK CELI. or relevant compartment. arid at the point of entry. For condition a), the indicators shall operate for a minimum of 10 s prior to movement of a hazardous moving part along the most significant axis. If condition a can occur while condition b) is in effect, there shall be a change of light sequencing such that the change in status will be obvious to persons in er at the point of entry to the WORK CELL.
Compliance Is checked by inspection and test.
Restarting of the mechanical system shall only be possible by initiating a start control procedure after the emergency stop control has been manually reset.
For equipment where a person may completely enter the WORK CELL, the emergency stop system shall include a minimum of Iwo emergency stop controls, one outside the CELL and one within the WORK CELl. The system start up procedure shall include a non-hazardous method to ensure no person is present in the WORK CtLL. II it can be shown, after application of the 7.1 single fault tests to the movement control circuitry or other sensing means, that such tests do not by-pass the non-hazardous start up procedure, the emergency stopping distance test of this subclause is not required
For equipment where a person may only partially enter a WORK CELL or compartment, a minimum of one emergency stop control shall be provided outside of the woii< c€i.t. The emergency stop system shall be operable by the person needing to have access to the woiix cEu.. An emergency stop control provided outside the WORK CELL shall be readily visible and shall be located on the equipment such that the person operating it can see it the WORK cru is occupied. The installation instructions shall require that space be provided around the control so that an OPERATOR Of 5ERVCE PERSON can easily reach and activate it. An emergency stop control provided inside the WORK cu. shall be readily accessible from anywhere inside the K cat and shall be provided with lighting to permit easy identification. It shall consist of a red palm or mushroom head button or be provided with an indirect arrangement, such as an easily identifiable red safety cable, that activates the emergency stop system.