Carrier 58MCA User Manual

Page 10

NOTE:

Leave blower access panel installed to maintain power to

control center to view current LED status.

4. BRIEFLY remove either wire from the main limit switch until

the LED goes out, then reconnect it.

Make sure limit switch wire does not contact any metallic
component such as the gas valve. If wire is shorted, 3-amp
fuse on control center will blow.

NOTE:

If wire to main limit is disconnected longer than 4 sec, the

control senses limit circuit is open. Main blower will start and
retrieval request will be ignored.

5. When above items have been completed, the component test

sequence will occur as described in the Component Test
Sequence section above.

NOTE:

Be sure to record the status code which is flashed 4 times

at start of component test for further troubleshooting.

6. 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.

INITIATING COMPONENT TEST AND RETRIEVING STA-
TUS CODE BY JUMPERING CONTROL TEST TERMINAL

1. Remove main furnace door.

2. Remove blower access panel.

3. Manually close blower access panel door switch. Use a piece

of tape to hold switch closed.

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
electrical shock, 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 C

terminal on thermostat connection block. (See

Fig. 13.)

NOTE:

If TEST to C

terminals are jumpered longer than 2 sec,

LED will flash rapidly, and retrieval request will be ignored.

5. When above items have been completed, the component test

sequence will occur as described in the Component Test
Sequence section above.

NOTE:

Be sure to record the status code which is flashed 4 times

at start of component test for further troubleshooting.

6. After component test is completed and furnace is operating

properly, release blower access panel door switch, replace
blower access panel, and replace main furnace door.

Step 9—Checking Heat Tape Operation
(If Applicable)

In applications where the ambient temperature around the furnace
is 32°F or lower, freeze protection measures are required. If this
application is where heat tape has been applied, check to ensure it
will operate when low temperatures are present.

NOTE:

Heat tape, when used, should be wrapped around the

condensate drain trap and drain line. There is no need to use heat
tape within the furnace casing. Most heat tapes are temperature

activated, and it is not practical to verify the actual heating of the
tape. Check the following:

1. Check for signs of physical damage to heat tape such as nicks,

cuts, abrasions, gnawing by animals, etc.

2. Check for discolored heat tape insulation. If any damage or

discolored insulation is evident, replace heat tape.

3. Check that heat tape power supply circuit is on.

Step 10—Winterizing

Freezing condensate left in the furnace will damage the
equipment.

If the furnace will be off for an extended period of time in a
structure where the temperature will drop to 32°F or below,
winterize as follows:

1. Turn off electrical supply to furnace.

2. Remove main furnace door.

3. Disconnect drain tube from inducer housing. (See Fig. 14.)

4. Insert funnel in drain tube and pour antifreeze, propylene

glycol (RV, swimming pool antifreeze, or equivalent) into
furnace until it is visible at point where condensate enters open
drain. (See Fig. 15.)

5. Reconnect drain tube to inducer housing.

6. Replace main furnace door.

Do not use ethylene glycol (Prestone II antifreeze/coolant or
equivalent automotive type). Failure of plastic components
will occur.

If this furnace is installed in an unconditioned space where
the ambient temperatures may be 32°F or lower, freeze
protection measures must be taken.

A93058

F MINIMUM INSTALLED

AMBIENT OR FREEZE
PROTECTION REQUIRED