TABLE 15—FUNCTION LIGHT CODE AND DISPLAY LOCATION
CODE | T’STAT | UNIT | DEFINITION | * | POSSIBLE CAUSE | |
Constant flash | — | X | No demand | 9 | — | |
No pause | Stand by | |||||
|
|
|
| |||
1 flash | — | X | 8 | — | ||
w/pause | ||||||
|
|
|
|
| ||
2 flashes | — | X | 7 | — | ||
w/pause | ||||||
|
|
|
|
| ||
3 flashes | X | X | Ambient thermistor failure | 6 | — | |
w/pause | ||||||
|
|
|
|
| ||
4 flashes | X | X | Coil thermistor failure | 5 | — | |
w/pause | ||||||
|
|
|
|
| ||
3 flashes |
|
|
|
| Thermistor drift, wrong location | |
|
|
|
| Incorrect wiring | ||
pause | X | X | Thermistor out of range** | 4 | ||
Incorrect refrigerant charge | ||||||
4 flashes |
|
|
|
| ||
|
|
|
| Dirty indoor/outdoor coil | ||
|
|
|
|
| ||
5 flashes |
|
| Pressure switch trip |
| Dirty outdoor coil | |
X‡ | X | 3 | Refrigerant overcharge | |||
w/pause | (LM1/LM2) | |||||
|
|
| Wrong indoor coil | |||
|
|
|
|
| ||
6 flashes |
|
|
|
| Low refrigerant charge | |
X | X | Compressor PTCs out of limit | 2 | Compressor mechanical problem | ||
w/pause† | ||||||
|
|
|
| Dirty indoor/outdoor coil | ||
|
|
|
|
| ||
Constant light |
|
|
|
| Equipment or electrical service | |
No pause | X | X | Board failure | 1 | ||
not grounded | ||||||
No flash |
|
|
|
| ||
|
|
|
|
|
*Function light signals order of importance; in case of
†Signal at thermostat will occur after 3 consecutive attempted restarts and lockout has occurred.
‡ Will be energized if pressure switch remains open for 1 hr. **Check both thermistors to determine which is faulty.
| 70 |
|
|
|
|
|
|
|
|
| 60 |
|
|
|
|
| HIGH SPEED |
| |
| HIGH |
|
|
|
|
|
| ||
| SPEED | CAPACITY |
| BALANCE POINT | |||||
|
|
| |||||||
| 50 |
|
|
|
| ||||
(1000'S) |
|
|
|
|
|
| |||
|
|
|
|
|
|
| |||
40 |
|
|
|
|
|
|
|
| |
LOW |
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
| |
BTU | SPEED | CAPACITY |
|
|
| STRUCTURE | |||
30 |
|
|
|
| BALANCE POINT | ||||
|
|
|
|
| |||||
| 20 |
|
|
|
| LOW SPEED |
|
| |
|
|
|
|
|
|
|
| ||
|
|
|
|
|
| BALANCE POINT |
| ||
| 10 |
|
|
|
|
|
|
|
|
| 50 | 60 |
| 70 | 80 | 90 | 100 | 110 | 120 |
TEMPERATURE (°F)
A91282
Fig. 35—Typical Cooling Balance Points
DEFROST
The
2)or less, and the selected defrost time (interval) has been accumulated during unit operation. Termination occurs when the coil thermistor reaches 80°F (± 5) or the defrost period reaches a maximum of 10 minutes.
Defrost always occurs in high speed unless the
By placing a jumper across the speedup terminals for a minimum of 5 sec and then removing it, the unit initiates a defrost cycle. (See Fig. 34.) The cycle occurs only if the outdoor ambient is less than 50°F, regardless of outdoor coil temperature. The cycle terminates when the coil thermistor reaches 80°F ( ± 5) or the defrost period reaches a maximum of 10 minutes.
FURNACE INTERFACE
This feature provides a
When the option is selected, the heat pump will be locked out of operation any time there is a thermostat demand for W2 or the outdoor ambient is below the
BALANCE POINT
This feature can be used in 2 different options: furnace interface or
When using this option to stage electric heat, first stage is energized by a W2 demand, and second stage is energized by a W3 demand. Select the W3 desired temperature by rotating the
If the system is operating in