Furnish Rolling Grilles, series 250 as manufactured by “ADT” complete with curtain, hood, guides, counterbalance and options as specified.

Curtain construction shall be ADT brick pattern or straight pattern with all exposed metal to be galvanized or aluminum. Continuous horizontal solid rods 2 1/4″ o.c. are to be covered with tubular spacers. Spacer to be vinyl. Links to be aluminum. Rods to be bright basic or galvanized wire. End links to be furnish to prevent grille from exiting guides. Each curtain shall receive a bottom bar to maintain grille alignment and posture.

Bottom bar shall consist of two steel shop primed angles a minimum 1/8″ thick.

Spring counterbalance is to be housed in a steel pipe of the appropriate diameter and wall thickness as to support curtain. Deflection shall be limited to a maximum of .03″ per ft. of door width. Springs are to consist of helical torsion types designed to meet a 25% load factor. Safety factor allows for safe operation, ease of use, and longer spring life. Springs are to be grease packed and anchored, using a cast iron anchor, to a cold rolled steel inner shaft. Spring tension shall be fully adjustable from outside of end bracket plate. To insure smooth operation end bracket plates shall contain sealed ball bearings to minimize wear of pipe shaft.

End bracket plates shall consist of steel plate no less than 3/16″ thick. Bracket plates are to house pipe shaft and counterbalance assembly. Shaft is attached to plate by sealed ball bearings fitted onto plate.

Guides shall consist of structural steel angles a minimum 3/16″ thick. The guide depth shall be of a length adequate to provide for proper slat penetration and specified windloading.

Hoods shall consist of a minimum of #24 U.S. gauge steel. Hoods are designed to protect and house counterbalance assembly. To prevent hood sag intermediate supports shall be furnished as required.
Locking for manual and chain operated doors to be slidebolts mounted on bottom bar with provisions for padlocks. Gearing within motors to be self locking.

Finish all non-galvanized surfaces shall receive a shop coat of rust inhibiting primer. Field painting not included in this section.

Installation to be by ADT or by an authorized dealer.

Options:

• XT 2000 Operating System
• Sloping bottom bar
• Kick plate
• Security panel
• Bottom bar with rubber astragal
• Designer Hood
• Remote control*
• Safety edge*
• Timer to close*

* Available only with motorized units.