Carrier 50JZ024 Installation, Start-Up And Service Instructions Manual Download Page 6

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and the wire tie on the right to be cut is located approximately
6 in. down the tube sheet.

Step 5—Select and Install Ductwork

The design and installation of the duct system must be in
accordance with the standards of the NFPA for installation of
non-residence type air conditioning and ventilating systems, NFPA
90A or residence-type, NFPA 90B and/or local codes and ordi-
nances.

Select and size ductwork, supply-air registers, and return air grilles
according to ASHRAE (American Society of Heating, Refrigera-
tion, and Air Conditioning Engineers) recommendations.

The unit has duct flanges on the supply- and return-air openings on
the side of the unit.

When designing and installing ductwork, consider the following:

For vertical supply and return units, tools or parts could drop
into ductwork and cause serious injury or death. Install a 90
degree turn in the return ductwork between the unit and the
conditioned space. If a 90 degree elbow cannot be installed,
then a grille of sufficient strength and density should be
installed to prevent objects from falling into the conditioned
space. Units with electric heaters require 90 degree elbow in
supply duct.

1. All units should have field-supplied filters or accessory filter

rack installed in the return-air side of the unit. Recommended
sizes for filters are shown in Table 1.

2. Avoid abrupt duct size increases and reductions. Abrupt

change in duct size adversely affects air performance.

IMPORTANT:

Use flexible connectors between duct-work and

unit to prevent transmission of vibration. Use suitable gaskets to
ensure weather tight and airtight seal. When electric heat is
installed, use fireproof canvas (or similar heat resistant material)
connector between ductwork and unit discharge connection. If
flexible duct is used, insert a sheet metal sleeve inside duct. Heat
resistant duct connector (or sheet metal sleeve) must extend 24-in.
from electric heater element.

1. Size ductwork for cooling air quantity (cfm). The minimum

air quantity for proper electric heater operation is listed in
Table 2. Heater limit switches may trip at air quantities below
those recommended.

2. Seal, insulate and weatherproof all external ductwork. Seal,

insulate and cover with a vapor barrier all ductwork passing
through conditioned spaces. Follow latest Sheet Metal and Air
Conditioning Contractors National Association (SMACNA)
and Air Conditioning Contractors Association (ACCA) mini-
mum installation standards for residential heating and air
conditioning systems.

3. Secure all ducts to building structure. Flash,weatherproof, and

vibration-isolate duct openings in wall or roof according to
good construction practices.

CONVERTING

HORIZONTAL

DISCHARGE

UNITS

DOWNFLOW (VERTICAL) DISCHARGE UNITS

Before performing service or maintenance operations on
system, turn off main power to unit. Turn off accessory heater
power switch if applicable. Electrical shock could cause
serious injury or death.

1. Open all electrical disconnects before starting any service

work.

Fig. 5—Unit Leveling Tolerances

C99065

MAXIMUM ALLOWABLE

DIFFERENCE (in.)

A-B

B-C

A-C

1/4

Fig. 6—Slab Mounting Detail

C99096