Adjustable drives:
fixed-pitched sheaves are standard on motors 25 HP and larger. An adjustable-pitch motor sheave is provided in lieu of the standard fixed-pitch sheave.
Casing insulation:
adds 1", 1.5 lb density insulation to inner surface of unit's walls and ceiling, casing liners are standard with this option.
Casing liners with insulation:
prevents insulation fibers from being drawn into air stream and discharged into conditioned space, and prevents physical abuse and moisture damage to insulation. Made of galvanized steel.
Extended grease lines:
lubrication lines from blower bearings to a common point on the unit's exterior. Units with permanently lubricated bearings to be changed to pillow block-type.
Floor-mounted spring isolators:
box-type lifting points replace standard lifting eyes; 1-inch deflection spring mounts shipped loose for field installation.
Hanging spring isolators, 1-inch:
shipped loose for field installation.
Painted casings:
one coat of beige air-dried enamel over a vinyl wash primer.
Pillow-block bearings, 100,000 hr:
standard on all units ordered with an industrial blower, and are rated at 100,000 to 200,000 hours; available on smaller units with standard, permanently lubricated ball bearings.
Spring-isolated blower and motor:
mounted on a 1" deflection spring isolated base. A flexible duct connects the fan outlet to the unit's casing.
Two-speed damper package:
provides burner-profile dampers that automatically maintain the correct burner velocity. Also dual airflow switches and rate-limiting control are included to prevent over-firing on low speed.