Appendix D Rack Build Standard

Engineering Division Electronic Equipment Build Standard Appendix D, Rack Build Standard V1
Revision 1

D.1 Scope
This document provides the requirements for racks installed at LBNL for R&D and experimental use. This document incorporates requirements commonly required to be applied from UL standards for electrical safety. Additional requirements may apply. Refer to section 7 for the references used in this document.
These standards provide requirements from the UL standards for Industrial Control Equipment (UL508) and Industrial Control Panels (UL508A). For grounding and bonding requirements refer to the LBNL Electrical Equipment Build Standard or the Electrical Standard for Industrial Machinery (NFPA 79).

D.2 Construction
D.2.1 General
D.2.1.1 An enclosure shall be constructed so as to reduce the risk of unintentional contact with enclosed electrical devices, and to provide internal devices with protection from external conditions.
D.2.1.2 A part of an enclosure, such as a door or a cover, shall be provided with a means (such as latches, locks, mechanical interlocks, or screws) for firmly securing it in place.
D.2.1.3 A door more than 48 inches (1.2 m) long on the hinged side shall be provided with one of the following:
a) A multipoint latch operated by a single knob or handle; b) Two or more snap latches or captive fasteners; or
c) One knob-operated latch and one snap latch or captive fastener. D.2.1.4 A door giving access to a fuse or any portion of a circuit breaker other than the operating handle shall shut closely against a 1/4-inch (6.4-mm) rabbet as illustrated in Figure 1 or the equivalent.

Engineering Division Electronic Equipment Build Standard Appendix D, Rack Build Standard V1
Revision 1

Figure 1, Overlapping rabbet

D.3 Power outlets
D.3.1 Power Outlets on the Equipment
D.3.1.1 Power outlets should be designed for the intended load plus a headroom factor of an additional 80%. The expected load, due to future changes to the system, should not exceed 80% of the design capacity.
D.3.1.2 A receptacle located inside a rack provided for the permanent connection of a load shall be oriented to reduce the risk of electric shock when removing or inserting plugs.
Power strips located inside a rack should be mounted at a right angle if this orientation does not obstruct the sight line and the ability for personnel to see exposed prongs. D.3.1.3 If any standard power supply outlet in the equipment is accessible to personnel, a marking shall be placed in the vicinity of the outlet to show the maximum