Warning, Caution – Carrier 50HCQA User Manual

Page 7

A-B

0.5” (13)

B-C

1.0” (25)

A-C

1.0” (25)

MAXIMUM ALLOWABLE

DIFFERENCE IN. (MM)

C06110

Fig. 4 -- Unit Leveling Tolerances

Step 5 — Field Fabricate Ductwork

Cabinet return-air static pressure (a negative condition)

shall not exceed 0.35 in. wg (87 Pa) with economizer or

0.45 in. wg (112 Pa) without economizer.

For vertical ducted applications, secure all ducts to roof

curb and building structure. Do not connect ductwork to
unit.

Insulate and weatherproof all external ductwork, joints,

and roof openings with counter flashing and mastic in

accordance with applicable codes.

Ducts passing through unconditioned spaces must be

insulated and covered with a vapor barrier.

If a plenum return is used on a vertical unit, the return

should be ducted through the roof deck to comply with

applicable fire codes.

For Units with Accessory Electric Heaters —

Horizontal applications require a minimum clearance to

combustible surfaces of 1--in (25 mm) from duct for first

12--in (305 mm) away from unit. Vertical applications do not

require a minimum clearance.

Minimum clearance is not required around ductwork.

Outlet grilles must not lie directly below unit discharge.
NOTE: A 90--degree elbow must be provided in the

ductwork to comply with UL (Underwriters Laboratories)
code for use with electric heat.

PERSONAL INJURY HAZARD
Failure to follow this warning could cause personal

injury.
For vertical supply and return units, tools or parts

could drop into ductwork and cause an injury. 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. Due to

electric heater, supply duct will require 90--degree

elbow.

WARNING

Step 6 — Rig and Place Unit

Keep unit upright and do not drop. Spreader bars are not

required if top crating is left on unit. Rollers may be used to

move unit across a roof. Level by using unit frame as a

reference. See Table 1 and Fig. 5 for additional information.

Lifting holes are provided in base rails as shown in Fig. 5.

Refer to rigging instructions on unit.

UNIT DAMAGE HAZARD
Failure to follow this caution may result in

equipment damage.
All panels must be in place when rigging. Unit is not

designed for handling by fork truck.

CAUTION

Before setting the unit onto the curb, recheck gasketing on

curb.

50H