Accessories; Direct Venting; Removal Of Existing Furnaces From Common Vent Systems; Combustion-Air And Vent Piping - Carrier 58MXA Operating And Instruction Manual

Step 3—Accessories
1. Electronic Air Cleaner (EAC)
Two spring clamp terminals (for 12 gage maximum, solid or
stranded wire), marked EAC-1 and EAC-2, are provided for
EAC connection. (See Fig. 25.) These terminals are energized
with 115v (1.5-amp maximum) during blower motor opera-
tion. To connect EAC power leads to furnace control center,
strip approximately 1/8 in. of insulation from wire. Open
terminal by depressing switch arm with a screwdriver or
finger, and insert wire as shown in Fig. 26.
Fig. 26—EAC Terminals on Control Center
2. Humidifier (HUM)
Screw terminals (HUM and C
humidifier connection. (See Fig. 24.) HUM terminal is ener-
gized with 24v (0.5-amp maximum) after inducer motor
prepurge period.
NOTE: A field-supplied, 115-v controlled relay connected to
EAC terminals may be added if humidifier operation is desired
during blower operation.

DIRECT VENTING

The 58MXA Furnaces require a dedicated (one 58MXA furnace
only) direct-vent system. In a direct-vent system, all air for
combustion is taken directly from outside atmosphere, and all flue
products are discharged to outside atmosphere.
Step 1—Removal of Existing Furnaces from
Common Vent Systems
If furnace being replaced was connected to a common vent system
with other appliances, the following steps shall be followed with
each appliance connected to the venting system placed in opera-
tion, while any other appliances connected to the venting system
are not in operation:
1. Seal any unused openings in the venting system.
2. Inspect the venting system for proper size and horizontal pitch
as required in the National Fuel Gas Code, ANSI Z223.1 or
the CAN/CGA B149 Installation Codes and these instructions.
Determine that there is no blockage or restriction, leakage,
corrosion, and other deficiencies which could cause an unsafe
condition.
3. In so far as is practical, close all building doors and windows
and all doors between the space in which the appliance(s)
connected to the venting system are located and other spaces
of the building. Turn on clothes dryers and any appliance not
connected to the venting system. Turn on any exhaust fans,
such as range hoods and bathroom exhausts, so they shall
operate at maximum speed. Do not operate a summer exhaust
fan. Close fireplace dampers.
EAC1
EAC2
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) are provided for 24-v
OM
4. Follow the lighting instructions. Place the appliance being
inspected in operation. Adjust thermostat so appliance shall
operate continuously.
5. Test for draft hood equipped appliance spillage at the draft
hood relief opening after 5 minutes of main burner operation.
Use the flame of a match or candle.
6. After it has been determined that each appliance connected to
the venting system properly vents when tested as outlined
above, return doors, windows, exhaust fans, fireplace damp-
ers, and any other gas-burning appliance to their previous
conditions of use.
7. If improper venting is observed during any of above tests, the
venting system must be corrected.
Vent system or vent connectors may need to be resized. For any
other appliances when resizing vent systems or vent connectors,
system or connector must be sized to approach minimum size as
determined using appropriate table found in the NFGC or NSC-
NGPIC.
Step 2—Combustion-Air and Vent Piping
GENERAL
Combustion-air and vent pipe fittings must conform to American
National Standards Institute (ANSI) standards and American
Society for Testing and Materials (ASTM) standards D1785
(schedule-40 PVC), D2665 (PVC-DWV), D2241 (SDR-21 and
SDR-26 PVC), D2661 (ABS-DWV), F628 (schedule-40 ABS), or
F891 (PVC-DWV cellular core). Pipe cement and primer must
conform to ASTM standards D2564 (PVC) or D2235 (ABS). See
Table 5 for maximum pipe lengths and Fig. 31, 32, 33, 34, and 35
for exterior piping arrangements.
In Canada construct all combustion-air and vent pipes for this unit
of CSA or ULC certified schedule-40 PVC, PVC-DWV or
ABS-DWV pipe and pipe cement. SDR pipe is NOT approved in
Canada.
NOTE: Furnace combustion-air and vent pipe connections are
sized for 2-in. pipe. Any pipe size change should be made outside
furnace casing in vertical pipe. (See Fig. 27.) This allows proper
drainage of vent condensate.
NOT IN
HORIZONTAL
SECTION
Fig. 27—Combustion-Air and Vent Pipe Diameter
Transition Location and Elbow Configuration
Combustion-air and vent pipes must terminate together in same
atmosphere pressure zone, either through roof or sidewall (roof
termination preferred), using accessory termination kit. See Table
4 for required clearances.
20
FURNACE
PIPE DIAMETER
TRANSITION IN
VERTICAL SECTION
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