035-19315-001-A-0603
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Unitary Products Group
15. If none of the above correct the error, replace the
UCB.
UNIT 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.
Current alarms or active restrictions are flashed on the
UCB LED. Pressing and releasing the ALARMS 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 approxi-
mately 2 seconds.
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 button once.
MAINTENANCE
NORMAL MAINTENANCE
FILTERS
Inspect once a month. Replace disposable or clean
permanent type as necessary. DO NOT replace per-
manent type with disposable. The dimensional size of
the replacement filter must be the same as the
replaced filter.
MOTORS
Outdoor fan motors are permanently lubricated and
require no maintenance.
Indoor Blower Motor and Drive - The indoor blower
motor features ball bearings that do not require
periodic lubrication. Periodic lubrication of the motor
and bearings can extend the life of components but is
optional.
On an annual basis, check the motor for accumulations
of dust, etc. that may block the cooling slots in the
motor shell. Check for loose, damaged or misaligned
drive components. Check that all mounting bolts are
tight. Replace defective parts as required.
TABLE 29: UNIT CONTROL BOARD FLASH CODES
Flash Code
Description
On Steady
Control Failure - Replace Control
Heart Beat
Normal Operation
1 Flash
Not Applicable
2 Flashes
Control waiting ASCD
1
1.
These flash codes do not represent alarms.
3 Flashes
HPS1 - Compressor Lock out
4 Flashes
HPS2 - Compressor Lock out
5 Flashes
LPS1 - Compressor Lock out
6 Flashes
LPS2 - Compressor Lock out
7 Flashes
FS1 - Compressor Lock out
8 Flashes
FS2 - Compressor Lock out
9 Flashes
Ignition Control Locked Out/
Ignition Control Failure / Limit Switch Trip / No
Jumper Plug in Heat Section
10 Flashes
Compressors Locked Out On Low
Outdoor Air Temperature
1
11 Flashes
Compressors Locked Out Because The
Economizer Is Using Free Cooling
1
12 Flashes
Fan Overload Switch Trip
13 Flashes
Compressor Held Off Due To Low Voltage
1
14 Flashes
EEPROM Storage Failure (Control Failure)
OFF
No Power or Control Failure
Prior to any of the following maintenance pro-
cedures, shut off all electric power to the unit to
prevent personal injury.
Damage can occur if the bearings are overlu-
bricated. Use grease sparingly.
Perform all maintenance operations on the
blower motor with electric power disconnected
from the unit. Do not attempt to lubricate bear-
ings with the unit in operation.
