Start-Up Procedures; General; Prime Condensate Trap With Water; Purge Gas Lines - Carrier 58MXA Installation, Start-Up, And Operating Instructions Manual

6. When above items have been completed, the following will
occur:
a. LED flashes a fault code 4 times. Record this fault code for
further troubleshooting.
b. Inducer motor operates for 10 sec, then turns off,
c. Hot surface ignitor is energized for 15 sec, then de-
energized.
d. Main blower operates at cooling speed for 10 sec, then
turns off.
e. Main blower operates at heating speed for 10 sec, then
turns off.
7. After component test is completed and LED is ON continu-
ously indicating the furnace is ready to operate when a signal
from the thermostat is received, replace main furnace door.
JUMPERING CONTROL TEST TERMINAL
1. Remove main furnace door.
2. Remove blower access panel.
3. Manually close blower access panel door switch.
→
Blower access panel door switch opens 115-v power to
control center. No component operation can occur. Caution
must be taken when manually closing this switch for service
purposes. Failure to follow this warning could result in
personal injury or death.
4. BRIEFLY short (jumper) TEST, 1/4-in. quick-connect termi-
nal on control center (adjacent to the LED diagnostic light)
and the Com terminal on thermostat connection block. (See
Fig. 14.)
NOTE: If TEST to Com terminals are jumpered longer than 2 sec,
LED will flash rapidly, and retrieval request will be ignored.
5. Component Test will function as described above.
6. After component test is completed and furnace is operating
properly, remove device used to manually close blower access
panel door switch, replace blower access panel, and replace
main furnace door.

START-UP PROCEDURES

Step 1—General
1. Furnace must have a 115-v power supply properly connected
and grounded. Proper polarity must be maintained for correct
operation.
NOTE: Proper polarity must be maintained for 115-v wiring. If
polarity is incorrect, control center fault indicator light will flash
rapidly and furnace will not operate.
2. Thermostat wire connections at terminals R, W, G, and Y
must be made at 24-v terminal block on control center.
3. Natural gas service pressure must not exceed 0.5 psig (14-in.
wc), but must be no less than 0.16 psig (4.5-in. wc).
4. Blower access door must be in place to complete 24-v
electrical circuit to furnace.
These furnaces are equipped with a manual reset limit switch
in burner box. This switch will open if an overheat condition
(rollout) occurs in burner enclosure. Correct inadequate
combustion-air supply or improper venting condition and
reset switch. DO NOT jumper this switch.
Before operating furnace, check each manual reset switch for
continuity. If necessary, press button to reset switch.
Step 2—Prime Condensate Trap with Water
Condensate trap must be PRIMED or proper draining may not
occur. The condensate trap has 2 internal chambers which can
ONLY be primed by pouring water into the inducer drain side
of condensate trap.
1. Remove upper inducer housing drain connection cap. (See
Fig. 43.)
2. Connect field-supplied 1/2-in. ID tube to upper inducer
housing drain connection.
3. Insert field-supplied funnel into tube.
4. Pour 1 quart of water into funnel/tube. Water should run
through inducer housing, overfill condensate trap, and flow
into open field drain. (See Fig. 44.)
5. Remove funnel and tube from inducer housing and replace
drain connection cap and clamp.
Step 3—Purge Gas Lines
If not previously done, purge lines after all connections have been
made and check for leaks.
Never purge a gas line into a combustion chamber. Never use
matches, candles, flame, or other sources of ignition for
purpose of checking leakage. Use a soap-and-water solution
to check for leakage. Failure to follow this warning could
result in fire, explosion, personal injury, or death.
Step 4—Adjustments

SET GAS INPUT RATE

Measured gas input must be within ±2 percent of gas input on unit
rating plate. (0-2000 ft altitude.)
There are 2 methods of adjusting gas input rate. The preferred
method is by using Table 7 and following instructions in item 1.
The second method is by clocking gas meter as outlined in item 2.
Item 2 must be used for altitudes above 2000 ft.
1. Determine natural gas orifice size and manifold pressure for
correct input by using Table 7, then adjust manifold pressure
per item 3.
a. Obtain average yearly heat value for local gas supply.
b. Obtain average yearly specific gravity for local gas supply.
c. Verify furnace model. Table 7 can only be used for model
58MXA furnaces.
d. Find natural gas heat value and specific gravity in Table 7.
e. Follow heat value line and specific gravity line to point of
intersection to find orifice size and manifold pressure
settings for proper operation and given natural gas condi-
tion.
EXAMPLE:
Heating value = 1010 Btu/cu ft
Specific gravity = 0.62
Therefore: Orifice No. 44*
Manifold pressure 3.3-in. wc
* Furnace is shipped with No. 45 orifices. In this example
all main burner orifices must be changed and manifold
pressure adjusted.
Check and verify orifice size in furnace. NEVER ASSUME
ORIFICE SIZE; ALWAYS CHECK AND VERIFY.
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