Unit Control Board Flash Codes - York 20 Series Installation Manual

349215-JIM-B-1008

UNIT CONTROL BOARD FLASH CODES

Various flash codes are utilized by the unit control
board (UCB) to aid in troubleshooting. Flash codes are
distinguished by the short on and off cycle used
(approximately 200ms on and 200ms off). To show
normal operation, the control board flashes a 1 second
on, 1 second off "heartbeat" during normal operation.
This is to verify that the UCB is functioning correctly.
Do not confuse this with an error flash code. To prevent
confusion, a 1-flash, flash code is not used.
Alarm condition codes are flashed on the UCB lower
left Red LED, See Figure 28. While the alarm code is
being flashed, it will also be shown by the other LEDs:
lit continuously while the alarm is being flashed. The
total of the continuously lit LEDs equates to the number
TABLE 27: UNIT CONTROL BOARD FLASH CODES
FLASH CODE
On Steady This is a Control Failure
1 Flash Not Applicable
2 Flashes
Control waiting ASCD
3 Flashes HPS1 Compressor Lockout
4 Flashes HPS2 Compressor Lockout
5 Flashes LPS1 Compressor Lockout
6 Flashes LPS2 Compressor Lockout
7 Flashes FS1 Compressor Lockout
8 Flashes FS2 Compressor Lockout
9 Flashes Ignition Control Locked Out / Ignition Control Failure
10 Flashes
Compressors Locked Out on Low Outdoor Air Temperature
Compressors locked out because the Economizer is using free
11 Flashes
1
Cooling
12 Flashes Unit Locked Out due to Fan Overload Switch Failure
13 Flashes
Compressor Held Off due to Low Voltage
14 Flashes EEPROM Storage Failure
OFF No Power or Control Failure
1.
Non-alarm condition.
64
DESCRIPTION
1
1
of flashes, and is shown in the table. Pressing and
releasing the LAST ERROR button on the UCB can
check the alarm history. The UCB will cycle through the
last five (5) alarms, most recent to oldest, separating
each alarm flash code by approximately 2 seconds. In
all cases, a flashing Green LED will be used to indicate
non-alarm condition.
In some cases, it may be necessary to "zero" the
ASCD for the compressors in order to perform trouble-
shooting. To reset all ASCDs for one cycle, press and
release the UCB TEST/ RESET button once.
Flash codes that do and do not represent alarms are
listed in Table 27.
GREEN RED
LED LED
16
-
-
Flashing Off
Off Off
Off Off
Off Off
Off Off
Off Off
Off On
Off On
1
Flashing On
Flashing On
Off On
Flashing On
Off On
Off Off
Johnson Controls Unitary Products
RED RED
LED LED
8 4 2
- - -
- - -
Off On
Off On
On Off
On Off
On On
On On
Off Off
Off Off
Off On
Off On
On Off
On Off
On On
Off Off
RED
LED
1
-
-
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
Off