Communication And Status Function Lights - Carrier Infinity 25VNA0 Service Manual

Communication and Status Function Lights

Infinity Control, Green Communications (COMM)Light
A green LED (COMM light) on the outdoor board (see Fig. 2)
indicates successful communication with the other system
products. The green LED will remain OFF until communication is
established. Once a valid command is received, the green LED will
turn ON continuously. If no communication is received within 2
minutes, the LED will be turned OFF until the next valid
communication.
Amber Status Light
Amber colored STATUS light indicates operation and error status.
See Table 4 and Table 6 for 24VNA0 definitions and Table 5 and
Table 7 for 25VNA0 definitions.
S Two minute time delay to return to standby operation from last
valid communication.
S One minute time delay of outdoor fan at termination of cooling
mode when outdoor ambient is greater than or equal to 100_F
(37.8_C).
S Fifteen second delay at termination of defrost before the
auxiliary heat is de- -energized.
1
RED BRN
SEC2
SEC1
CC
PL3
HPS
PL2
RVS
PL1
COMM STATUS
C LS Y
UTIL
A B C NO
USE
Fig. 2 – Variable Speed Control Board
IMPORTANT: Though the 24VNA0 and 25VNA0 circuit
boards appear similar, they are not interchangeable. Use only
approved replacement parts for the model being serviced. The
software number and revision level are unique between type of
product.
YEL
BLU
EXV
PWM2 PWM1
PL4
SPT
PL11
CB
OST
PL6
OCT
OAT
J2
O
PL8
FORCED
DEFROST
MODEL
Defrost (25VNA0)
This user interface (UI) offers 5 possible defrost interval times: 30,
60, 90, 120 minutes, or AUTO. The default is AUTO.
Defrost interval times: 30, 60, 90, and 120 minutes or AUTO are
selected by the Infinity Control User Interface (dip switches are not
used.)
AUTO defrost adjusts the defrost interval time based on the last
defrost time as follows:
S When defrost time <3 minutes, the next defrost interval=120
minutes.
S When defrost time 3- -5 minutes, the next defrost interval=90
minutes.
S When defrost time 5- -7 minutes, the next defrost interval=60
minutes.
S When defrost time >7 minutes, the next defrost interval=30
minutes.
The control board accumulates compressor run time. As the
accumulated run time approaches the selected defrost interval time,
the control board monitors the coil temperature sensor for a defrost
demand. If a defrost demand exists, a defrost cycle will be initiated
at the end of the selected time interval. A defrost demand exists
when the coil temperature is at or below 32_F (0_C) for 4 minutes
during the interval. If the coil temperature does not reach 32_F
(0_C) within the interval, the interval timer will be reset and start
over.
S Upon initial power up the first defrost interval is defaulted to 30
minutes. Remaining intervals are at selected times.
S Defrost is only allowed to occur below 50_F (10_C) outdoor
ambient temperature.
The defrost cycle is terminated as described below.
S When OAT is > 25F (- -3.9 C), defrost terminates if outdoor
coil temperature (OCT) > 60F (+15.6C) (min. 4.5 minutes)
S When OAT is </= 25F (- -3.9C), defrost terminates if outdoor
coil temperature (OCT) > 45 F (+7.2C) (min. 3.25 minutes)
S Or 10 minutes has passed.
At the defrost termination, the outdoor fan output (ODF) will turn
on 15 seconds before the reversing valve switching.
NOTE: Compressor speed during defrost varies based on outdoor
conditions.
A11139
6