AQLA FAN SPEED CONTROLLER
FITTING AND CALIBRATION INSTRUCTION FOR
AQLA CONDENSER FAN SPEED CONTROLLER
MAXIMUM 3A OUTPUT
WARNING
Main voltage is present; care must be exercised when setting potentiometers.
METHOD OF OPERATION
The function of the AQLA low ambient control is to maintain an adequate evaporating temperature in an
Expansion Device feed air conditioning system in the cooling mode. The unit consists of a Control
Module and a Sensor which is fitted to one of the convenient liquid line exit from the condenser to
measure the temperature of the condensing refrigerant. The fan motor and its power supply are connected
to the controller, and the fan will then be automatically controlled to maintain a constant condensing
temperature-and therefore a constant head pressure.
When the power is turned on, the fan runs at full speed for approximately 10 seconds, then the sensor
measures the coil temperature and adjusts the fan speed to match the coil temperature to the set point,
which can be set between 20°C and 40°C. As the ambient air temperature rises and falls, the fan speed
increases and slows down, to produce the variable cooling effect needed to give constant pressure.
If the ambient temperature drops far enough to require a fan speed lower then the set minimum speed,
the fan will stop completely and the condenser is cooled by natural convection only. As the condensing
temperature rises again, the fan will restart with a "hard start"of full speed for 10 seconds, and then the
speed is again controlled by the sensor.
Before fixing, check that the package contents are correct.
Quantity
Package contents
1
AQLA Fan Speed Controller
1
Sensor Assembly
3
Buckle-clip
1
Adhesive Insulation (20mm X 80mm)
2
Tie Wrap(100mm)
1
Instruction Manual
3
Screw
FIXING
The controller should be mounted on the control panel within the condensing unit using 2 screws supplied.
Fasten it to any holes on control panel as long as there is enough space to install. If necessary, drill holes
to install on proper position.
When drilling, ensure that metal swarf does not foul any electronic components.
P/No.: 3828A20096C
Using Low-Ambient Control
for
High Efficiency Air Conditioner
SAFETY FIRST!
1. Disconnect All power supplies before starting installation or maintenance work.
2. The controller and sensor are to be safely enclosed within the condensing unit.
3. All electrical wiring must be carried out by a competent person, and must comply
with all National and Local electrical parts.
ELECTRICAL CONNECTIONS
It is essential that correct wiring connections are made. Read this instruction thoroughly before
proceeding and follow exactly in conjunction with the wiring diagrams.
Some condensing units are equipped with two fans. In that case, connect the leadwire of each motor to
terminal numbers 3 and 4 .
Some condensing units may require a separate controller with each fan. (Refer to Maxium Output)
Each controller and fan will be a separate electrical circuit.
Heat Pump Models
Where the Low Ambient Controller is to be used with a Heat Pump, the condenser fan needs to run at full
speed during the heating mode, and is only modulated during the cooling mode.
When fitted to a Heat Pump, terminal numbers 6 and 7 should be wired directly to the reversing solenoid
valve; in all cases both live and neutral side of solenoid valve be connected to the controller.
Cooling Only Models
On cooling units only, where a reversing solenoid valve is not fitted, terminal numbers 6 and 7 should be
left unconnected.
FITTING THE SENSOR
It is important that the sensor is correctly fixed.
1.Locate a return bend, two or three bends above a convenient liquid line exit from the condenser. This
should ideally be chosen with its temperature closest to that of discharge saturation temperature. The
discharge saturation temperature can be directly read from your gauges or with the aid of a touch probe
thermometer.
This signal is then fed into the Controller which alters the voltage supplied to the fan motor, to keep
the condensing temperature properly.
Note; If the sensor needs to be moved once fitted, it can be released by gently inserting the blade of a
small screwdriver into the clip.
2. Fit the sensor head, bead side, to the pipe with a smear of the white thermal compound. Reinforce
an appropriate buckle-clip with one of the tie wraps supplied and use the other to secure the cable to
the adjacent pipe. It is important to have a good thermal contact between the sensor and the condenser
tube, as this gives the controller its rapid yet damped response time, to give accurate control without
"hunting". Finally, insulate the area of the bend with the insulation provided. Incorrect operation will
result if the sensor is not adequately insulated and applied without thermal compound.
HEATING MODE
Fan speed control should not be used in the Heating mode; when heating, all fan(s) should operate at full
speed.
SETTING THE CONTROL
Final adjustments are best carried out in low ambient temperature. The controller has been factory set at
approximately 25°C, though this should always be verified at site. Should it be necessary to adjust the
controller, proceed as follows.
Adjustments should always be carried out with the condensing unit covers in place, so that no air is
short-circuited through the condenser coil.