Carrier 48VL-E Installation Instructions Manual page 10

48VL-(E, F): Installation Instructions
OUT
3˝ MIN
Fig. 8 – Sediment Trap
NOTE: Pressure test the gas supply system after the gas supply piping
is connected to the gas valve. The supply piping must be disconnected
from the gas valve during the testing of the piping systems when test
pressure is in excess of 0.5 psig. Pressure test the gas supply piping
system at pressures equal to or less than 0.5 psig. The unit heating
section must be isolated from the gas piping system by closing the
external main manual shutoff valve and slightly opening the
ground-joint union.
WARNING
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury, death
and/or property damage.
- Connect gas pipe to unit using a backup wrench to avoid
damaging gas controls.
- Never purge a gas line into a combustion chamber. Never test
for gas leaks with an open flame. Use a commercially available
soap solution made specifically for the detection of leaks to
check all connections. A fire or explosion may result causing
property damage, personal injury or loss of life.
- Use proper length of pipe to avoid stress on gas control
manifold.
- If a flexible connector is required or allowed by authority
having jurisdiction, black iron pipe shall be installed at furnace
gas valve and extend a minimum of 2 in. (51 mm) outside
furnace casing.
- If codes allow a flexible connector, always use a new connector.
Do not use a connector which has previously serviced another
gas appliance.
8. Check for gas leaks at the field-installed and factory-installed gas
lines after all piping connections have been completed. Use a
commercially available soap solution (or method specified by local
codes and/or regulations).
Step 9 – Install Duct Connections
The unit has duct flanges on the supply- and return-air openings on the
side and bottom of the unit. For downshot applications, the ductwork
connects to the roof curb (See Fig. 3
locations).
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
IN
TEE
NIPPLE
CAP
C99020
and Fig. 4 for connection sizes and
Configuring Units for Downflow (Vertical) Discharge
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury or death.
Before installing or servicing system, always turn off main power to
system and install lockout tag. There may be more than one disconnect
switch.
1. Open all electrical disconnects before starting any service work.
2. Remove horizontal (metal) duct covers to access vertical
(downflow) discharge duct knockouts in unit basepan. (See
!
PROPERTY DAMAGE HAZARD
Failure to follow this caution may result in property damage.
Collect ALL screws that were removed. Do not leave screws on rooftop
as permanent damage to the roof may occur.
3. For single-phase models only, on the discharge side only, remove
the insulation covering the downshot (plastic) knockout. Insulation
is held in place with aluminum tape. Please note that large chassis
units have 2 pieces of insulation, and only the piece over the
downshot knockout needs to be removed. Discard insulation.
4. To remove the downshot (plastic) knockouts for both supply and
returns, break front and right side connecting tabs with a
screwdriver and hammer. Push cover down to break rear and left
side tabs. These plastic knockouts are held in place with tabs
similar to an electrical knockout. Discard plastic knockout covers.
5. Set unit on roof curb.
6. Verify that the downshot ducts are aligned with the downshot
knockout areas.
7. Re-install horizontal (metal) covers as needed to seal unit. Ensure
openings are air and watertight.
NOTE: The design and installation of the duct system must be in
accordance with the standards of the NFPA for installation of
nonresidence-type air conditioning and ventilating systems, NFPA 90A
or residence-type, NFPA 90B; and/or local codes and ordinances.
10
WARNING
CAUTION
Fig. 9.)