Metal and Air Conditioning Contractors National Association
(SMACNA) and Air Conditioning Contractors of America
(ACCA) minimum installation standards for heating and air
conditioning systems. Secure all ducts to building structure.
14. Flash, weatherproof, and vibration-isolate all openings in
building structure in accordance with local codes and good
building practices.
Step 8—Install Electrical Connection
The unit cabinet must have an uninterrupted, unbroken
electrical ground to minimize the possibility of personal
injury if an electrical fault should occur. This ground may
consist of an electrical wire connected to the unit ground lug
in the control compartment, or conduit approved for electrical
ground when installed in accordance with NEC (National
Electrical Code) ANSI/NFPA (latest edition) and local elec-
trical codes. In Canada, follow Canadian Electrical Code
CSA (Canadian Standards Association) C22.1 and local
electrical codes. Failure to adhere to this warning could result
in personal injury or death.
Failure to follow these precautions could result in damage to
the unit being installed:
1. Make all electrical connections in accordance with NEC
ANSI/NFPA (latest edition) and local electrical codes
governing such wiring. In Canada, all electrical connec-
tions must be in accordance with CSA standard C22.1
Canadian Electrical Code Part 1 and applicable local
codes. Refer to unit wiring diagram.
2. Use only copper conductor for connections between
field-supplied electrical disconnect switch and unit. DO
NOT USE ALUMINUM WIRE.
3. Be sure that high-voltage power to unit is within operating
voltage range indicated on unit rating plate.
4. Do not damage internal components when drilling through
any panel to mount electrical hardware, conduit, etc. On
3-phase units, ensure phases are balanced within 2 percent.
Consult local power company for correction of improper
voltage and/or phase imbalance.
HIGH-VOLTAGE CONNECTIONS
The unit must have a separate electrical service with a field-
supplied, waterproof, disconnect switch mounted at, or within
Fig. 7—Condensate Trap
C99013
1” (25mm) MIN.
2” (50mm) MIN.
TRAP
OUTLET
Table 3—Minimum Airflow for Safe Electric Heater
Operation (Cfm)
SIZE
018
024
030
036
042
048
060
700
800
1000
1200
1400
1600
2000
Fig. 8—Supply and Return Duct Opening
C99011
SUPPLY
DUCT
OPENING
RETURN
DUCT
OPENING
Fig. 9—Vertical Duct Cover Removed
C99012
DUCT COVERS REMOVED
9