Instruction manual

use flexible connectors between ductwork and unit to prevent transmission of vibration. When electric heater is installed, use heat-resistant material
for flexible connector between ductwork and unit at discharge connection. Ductwork passing through unconditioned space must be insulated and
covered with vapor barrier.
Units equipped with 20-30kw electric heaters require a 1-in. clearance to combustible materials for the first 36 in. of supply duct.
Ductwork Acoustical Treatment
Metal duct systems that do not have a 90° elbow and 10 ft of main duct to first branch takeoff may require internal acoustical insulation lining.
As an alternative, fibrous ductwork may be used if constructed and installed in accordance with the latest edition of SMACNA construction
standard on fibrous glass ducts. Both acoustical lining and fibrous ductwork shall comply with National Fire Protection Association as tested by
UL Standard 181 for Class 1 air ducts.
PROCEDURE 3—ELECTRICAL CONNECTIONS
All products from the factory utilize a printed-circuit board (PCB) which has a low voltage circuit protective fuse (5 amp), fan motor speed tap
selection terminal (SPT), and time delay relay (TDR) jumper. To disable the TDR feature, sever the jumper wire JW1. (See Fig. 8.)
When a factory-approved accessory control package has been installed, check all factory wiring per unit wiring diagram and inspect factory wiring
connections to be sure none were loosened in transit or installation. If a different control package is required, see unit rating plate.
CAUTION:
If a disconnect switch is to be mounted on unit, select a location where drill or fastener will not contact
electrical or refrigerant components.
Before proceeding with electrical connections, make certain that supply voltage, frequency, phase, and ampacity are as specified on the unit rating
plate. See unit wiring label for proper field high- and low-voltage wiring. Make all electrical connections in accordance with the NEC and any
local codes or ordinances that may apply. Use copper wire only.
The unit must have a separate branch electric circuit with a field-supplied disconnect switch located within sight from and readily accessible from
the unit.
Fig. 3—Removal of Brackets on Modular Units
A95293
2 SCREWS
2 SCREWS
REAR CORNER
BRACKET
BLOWER BOX
COIL BOX
2 SCREWS
—4—