Carrier 58MVP Troubleshooting Manual page 18

Fault Code 23
INVALID BLOWER AIRFLOW SELECTION—This fault indicates improper A/C or CF switch setting. The -14
units can deliver sufficient airflow for 1-1/2 to 3-1/2 tons A/C and 600 to 1400 CFM for continuous fan. The -20
unit can deliver sufficient airflow for 2 to 5 tons A/C and 800 to 2000 CFM for continuous fan. If fault code is
flashing, unit still operates, but it defaults to closest allowable airflow.
NOTE: Boards with date codes of 9506 or later will flash fault code and set continuous fan airflow to same airflow as A/C if continuous fan
is adjusted to a higher airflow than A/C setting.
STEP
1. Turn power off and remove blower access panel.
2. Are air conditioning select switches A/C set properly? (See Table 2.)
Set air conditioning select switches A/C for proper tonnage as required by con-
3.
densing unit.
Go to page number indicated in Index for CLEANUP AND START-UP
4.
INSTRUCTIONS.
5. Are continuous fan select switches CF set properly? (See Table 3.)
Set continuous fan select switches CF for desired airflow. This setting should
6. normally be set to DEFAULT position unless a 2-speed AC/HP is part of sys-
tem. Use Table 4 for reference on 2-speed AC/HP airflow requirements.
Are continuous fan select switches CF set to a higher airflow than air condition-
7.
ing select switches A/C? (See Tables 2 and 3.)
8. Is furnace a 100 size?
The problem is in the A/C or CF selection circuit. The maximum cooling or con-
9.
tinuous fan airflow for this unit will be delivered.
Jiggle A/C and CF switches back and forth. If fault code continues to flash, re-
10.
place furnace control board.
The problem is in the A/C or CF selection circuit. The minimum cooling or con-
11.
tinuous fan airflow for this unit will be delivered.
Jiggle A/C and CF switches back and forth. If fault code continues to flash, re-
12.
place furnace control board.
AIR CONDITIONER AIRFLOW
(TONS)
1200 or
Default
1-1/2
2
2-1/2
3
3-1/2
4
5
X—Indicates allowable selection.
CONTINUOUS FAN
(CFM)
Default
600
800
1000
1200
1400
1600
2000
* Add 15% additional CFM when Bypass Humidifier switch SW-3 on control board is used.
X—Indicates allowable selection.
Table 2—Air Conditioning (A/C) Airflow Setup Switch Position
A/C SWITCH POSITION
(CFM)
A/C-1 A/C-2
OFF OFF
2000
600 ON OFF
800 OFF ON
1000 ON ON
1200 OFF OFF
1400 ON OFF
1600 OFF ON
2000 ON ON
Table 3—Continuous Fan (CF) Airflow Setup Switch Position
CF SWITCH POSITION
CF-1 CF-2
OFF OFF
ON OFF
OFF ON
ON ON
OFF OFF
ON OFF
OFF ON
ON ON
ALLOWABLE FURNACE MODEL SETUP
A/C-3 040-14
3 Tons
OFF
1200 CFM
OFF X
OFF X
OFF X
ON X
ON X
ON —
ON —
ALLOWABLE FURNACE MODEL SETUP
CF-3 040-14
OFF 565*
OFF X
OFF X
OFF X
ON X
ON X
ON —
ON —
18
YES NO
— —
5 3
— —
— —
7 6
— —
6 8
11 9
— —
— —
— —
— —
060-14 080-14
3 Tons 3 Tons
1200 CFM 1200 CFM
X X
X X
X X
X X
X X
— —
— —
060-14 080-14
515* 690*
X X
X X
X X
X X
X X
— —
— —
GO TO
2
—
4
INDEX
—
4
—
—
10
4
12
4
100-20
5 Tons
2000 CFM
—
X
X
X
X
X
X
100-20
860*
—
X
X
X
X
X
X