shall be held in place by tack welding, brazing, or one-way screws.
2.4.11.3
Ventilation
Ventilation openings in enclosures and cabinets shall conform to the
requirements of UL 1610.
2.4.11.4
Mounting
Unless otherwise indicated, sheet metal enclosures shall be designed for
wall mounting with top hole slotted. Mounting holes shall be in positions
which remain accessible when major operating components are in place and
the door is open, but shall be inaccessible when the door is closed.
2.4.11.5
Enclosure Locks
Locks and key-lock-operated switches required to be installed on component
enclosures shall be UL listed, round-key type with three dual, one
mushroom, and three plain pin tumblers, or shall have a pick resistance
equal to a lock having a combination of five cylinder pin and five-point
three-position side bar in the same lock. Keys shall be stamped "U.S.
GOVT. DO NOT DUP." Key-lock-operated switches shall be keyed differently
and shall be two-position, with the key retractable from either position.
Furnish two keys for each switch. Maintenance locks shall be of the
one-way key-pull type arranged so that the key can be withdrawn only when
the lock is in the locked position. Locks on components for maintenance
access shall be keyed alike; furnish only two keys for such locks. Deliver
keys, tagged with metal tags, accompanied by a manufacturer's certificate
which records the number of each key made.
2.4.12
Detection Sensors
Sensors shall detect penetration of the facility perimeter and protected
zones by unauthorized personnel or intruders, and shall conform to UL 634
or UL 639, as applicable. Unless otherwise specified, required sensor
power shall be plus 12 volts DC.
2.4.12.1
Interior Point Sensors
**************************************************************************
NOTE: If a high level of security is required such
as DCID 1/21, specify balanced magnetic switches
(BMS) in Section 13703, "Commercial Intrusion
Detection Systems."
**************************************************************************
a.
Door and window open detection
(1) Balanced Magnetic Switches (BMS): Switches shall be [surface
mounted] [recessed]. Switches shall have a balanced magnetic
field with a high probability of alarm if an external magnet is
introduced in defeat attempts. Provide each BMS with an
overcurrent protective device, rated to limit current to 80
percent of switch capacity. BMS shall be rated for a minimum
lifetime of one million operations. House BMS components in
enclosures made of nonferrous materials.
(2) Surface mounted BMS: House components used in outdoor
applications in weatherproof enclosures. The switch mechanism
SECTION 13702N
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