Carrier 50MQ - Manual (Page 2)

MOUNTING PAD
Step 3 — On the Ground: Mount Unit on a Solid,
Level Concrete Pad. See Fig. 2 for pad dimensions.
Ensure pad does not obstruct coil slots in unit base
pan. (Slots drain water during heating cycle).
Construct pad a minimum of 6 in. thick to provide
clearance under base pan coil slots for drainage and
ice buildup. In areas where prolonged subfreezing
temperatures, drifting or heavy snows occur, in­
crease clearance to 12 to 18 inches. If climatic
conditions dictate, construct an angle iron frame to
support unit 12 to 18 in. off concrete base. Cross
angle of frame must not obstruct base pan coil
slots. Extend a 24-in. gravel apron around pad for
condensate and defrost water drainage field.
Step 4 — On the Roof: Mount Unit on a Level
Platform or Frame.
Unit must be elevated for
proper clearance as described under ground in­
stallation above. Roof design and water drainage
must be planned to prevent unit and its duct
flashing from sitting in water.
for system air duct design. When designing and
installing ductwork, consider the following.
a. When connecting ductwork to unit, do not drill
holes in area shown below. Coil may be
damaged.
b. All units should have field-supplied filters in­
stalled in return air ductwork. Recommended
sizes for filters are shown in Table 1.
c Avoid abrupt duct size increases and reductions.
d. Use flexible connectors between ductwork and
unit to prevent transmission of vibration. When
electric heater is installed, use fireproof asbes-
• tos (or similar heat resistant material) con­
nector between ductwork and unit discharge
connection. Heat resistant duct connector must
extend 24 in. from electric heater element.
e. Size ductwork for cooling air quantity (cfm).
The minimum air quantity for safe electric
heater operation is;
INDOOR ELECTRIC HEATER KW
UNIT FAN 5.0 7.5 1 10.0 j 15.0 20.0
SPEED Cfm
50MQ022 Med-Lo 733 733 1 733 j
50MQ027 Med = H i 900 900 I 900 -
50MQ032 Med-Lo ]068 1068 1 1068 Í 1068 -
50MQ037 Med-Lo 1230 1230 ' 1230 j 1230 1230
m
Fig. 2 — Concrete Pad Dimensions
DUCTWORK
Step 5 — Connect Supply and Return Air Ductwork
to unit supply and return air duct connections. Refer
to Fig. 1 and Table 1 for unit supply and return air
connection sizes and locations.
Flanges are provided on unit for rectangular
duct connections. Fig. 3 shows a typical duct
system with 50MQ installed. Do not operate unit
longer than 5 minutes without ductwork. If neces­
sary, refer to Carrier System Design Manual, Part 2,
Heater limit switches may trip at air quantities
below those recommended.
f. All external ductwork must be insulated and
weatherproofed. Ducts passing thm uncondi­
tioned space must be insulated and covered
with vapor barrier in accordance with the latest
issue of SMACNA’s (Sheet Metal and Air
Conditioning Contractors National Association)
and NESCA’s (National Environmental Systems
Contractors Association) minimum installation
standards for residential heating and air condi­
tioning systems.
g. Secure all ducts to building structure. Weather­
proof duct openings in wall or roof according
to good construction practices.