Low Ambient control
| Model Number: | Used With: |
|---|---|
FIALOAM001* |
3 to 25 tons T/Y models with Symbio™ controls |
FIALOAM002* |
3 to 25 tons W/D models with Symbio controls |
Installation Instructions
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Mounting location
For detailed instructions, please reference the installation manual.
Pressure Transducer
For detailed instructions, please reference the installation manual.
Temperature Sensor Installation
Important: The existing thermistor used by the unit's controls measures the outdoor ambient air temperature.
- 3 to 12.5 tons - the existing thermistor is mounted on the condenser base pan in front of the compressors.
- 12.5 to 25 tons - the existing thermistor is mounted in the lower, right corner of the main control box.
The low ambient controller requires a second thermistor. Both locations are factory-designed with a second hole for the controller temperature sensor.
Wiring
For detailed instructions, please reference the installation manual.
Controller Settings and Operation
For detailed instructions, please reference the installation manual.
Jumper Position
- For non-heat pump applications, the heat pump select jumper must be in the default normally open (N.O.) position, and the REV. VALVE terminal must not be connected.
- For heat pump applications, move the jumper to the normally closed (N.C.) position and wire the REV. VALVE terminal with the REV Valve harness included in the kit.
Default jumper position
Controller Operation
- The LOAM controller is used to maintain head pressure within an acceptable range when ambient temperature falls below 50ºF. It reads discharge pressures from refrigeration circuits
- It cycles outdoor fan motors on and off to maintain the highest of the two discharge pressures at the selected setpoint anytime one or more compressors are operating. Above 50ºF, fans will be energized continuously.
Pressure Setpoint
- Set the pressure setpoint to the recommended value of 245 psig.
- At ambient temperatures lower than 50ºF, the controller will maintain discharge pressures between 15 psig above and 15 psig below the dialed pressure setpoint.
Troubleshooting guide
| Problem | Possible Cause | Possible Solution |
|---|---|---|
| No fan operation | No 24 volt control voltage | Check for 24 Vac at control and verify correct wiring. If wired correctly, check voltage across the transformer. |
| No line voltage | Check voltage across the brown, orange, and yellow OD motor leads. If no line voltage is present, verify all wiring is correct. | |
| Improper fan operation | Heat pump jumper not configured correctly | Refer to the IOM or correct hook-up diagram and verify the heat pump jumper is configured correctly. |
| Control is not wired correctly | See wiring diagrams. Ensure that the 24 Vac power supply is connected in-phase with the motor power supply | |
| No fan modulation | No need to modulate the fan | If pressure is equal to or greater than the head pressure control setpoint, the fan will be operating at full speed. |
| No input pressure to control | Check for proper transducer and Tee installation. Schrader valve depressor must depress Schrader valve enough to allow refrigerant into pressure transducer. | |
| Miswired | Check that the 24 Vac signal and the transducer are wired up correctly into the controller. | |
| Erratic fan operation | Control is not wired correctly | See wiring diagrams. |
| Pressure transducer problem | Check for proper transducer and Tee installation. Schrader valve depressor must depress Schrader valve enough to allow refrigerant into pressure transducer. | |
| Dirty or blocked condenser coil | Clean condenser coil. | |
| Fan motor is cycling on thermal overload | Dirty or blocked condenser coil | Clean condenser coil. |
| Unit fails to start | Incorrect/No voltage present | Using an AC voltmeter, measure the voltage between the 24 Vac terminals. It should read approximately 24 volts. Measure line voltage between LINE1, LINE2 and LINE 3 to confirm that line voltage is present. |
| Transducer malfunction or not installed | If lights are flashing alternatively, then no probe is connected or the probe is malfunctioning. When using a pressure transducer, with power applied to the control, use a voltmeter to measure volts DC between COMM and P1 or P2, where the wire is connected. The reading should be according to Table 4, p. 10. | |
| The fuse is blown and/or signs of damage on the unit | Miswired | The unit has been mis-wired and may be permanently damaged. |
Pressure vs. voltage
| Pressure (psig) | Voltage (Vdc) |
|---|---|
0 |
0.5 |
50 |
0.9 |
100 |
1.3 |
150 |
1.7 |
200 |
2.1 |
250 |
2.5 |
300 |
2.9 |
350 |
3.3 |
400 |
3.7 |
450 |
4.1 |
500 |
4.5 |
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.