Carrier 48MA/50ME016-040 - Manual (Page 9)

Condensate Drains — Pipe nipples covered with foam
rubber insulation are shipped in unit return air filter section
(6 nipples in units 48MA, 4 nipples in units 50ME). Install
a nipple in each drain connection on both sides of unit. See
Fig. 1 and 2 for drain locations. Be sure foam rubber seals
space between nipple and base rail opening to prevent rain
leaks.
Connect a drain line to drain connection under outdoor air
inlet grilles on both sides of unit. These drains need not be
trapped.
Install a trapped drain line on remaining connections on
lowest side of unit depending on unit pitch. If unit is level,
a trapped drain may be installed at each connection if de-
sired. Cap or plug unused connections on high side of unit
to prevent airflow between unit interior and outdoors.
Do not interconnect drains. Make each trap a minimum of
4 in. deep. Insulate trap against freeze-up or use flexible
material.
Gas Piping (48MA) — Unit is equipped for use with
type of gas shown on nameplate. Refer to latest edition of
ANSI Z223.1. Unit main gas connection and alternate gas
connection locations are shown in Fig. 1, 4, and 8. Do not
use gas supply pipe smaller than unit gas connection. Maxi-
mum allowable natural gas supply pressure is 10.0 in. wg;
minimum allowable natural gas supply pressure for full rate
input is 5.0 in. wg.
Pitch pipe 1 ⁄
4
in. per 15 ft. Pitch all horizontal pipe runs
upward to risers and from risers upward to meter. Install a
dirt and moisture pocket (drip leg) at each section of vertical
pipe run. Use only ground joint unions to ensure leakfree
joints. Use only pipe joint compounds that are resistant to
the action of liquefied petroleum gases.
OUTDOOR AIR INLET
(ONE ON EACH SIDE OF UNIT)
SHIPPING SHIELD
(BEHIND LOUVERS)
FLUE OUTLET
COVER
(48MA ONLY)
Fig. 6 — Shipping Shield Locations
(016-030 Units Shown)
NOTE: Dimension to suit job requirements. Twelve inches will bring
duct plenum to bottom of roof curb.
DIMENSIONS (in.)
UNIT
48MA,50ME
016,024 028,030 034,040
A* 7 5 ⁄ 8 7 5 ⁄ 8 7 5 ⁄ 16
B* 7 5 ⁄ 8 7 3 ⁄ 4 5 3 ⁄ 4
*Typical; both ends.
Fig. 7 — Field-Fabricated Zone Duct Plenum Detail
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