Application
1. Supply and exhaust ventilation systems for commercial, office and other public or industrial premises.
2. For premises with high requirements to noise level we offer units in low-noise modification
Design
The fan casing is made of galvanized steel.
Mounting
1. Mounting at any angle to wall or ceiling is performed with fastening brackets supplied with the unit.
2. The fan is powered by means of the external terminal box.
3. Electric connection and mounting shall be performed in compliance with the manual and wiring diagram on the terminal box.
Motor
1. The impeller with backward curved blades is powered by the single phase motor with external rotor and overheating protection with automatic restart.
2. Some standard sizes are available with high-powered motors.
3. The motor is equipped with ball bearings for long service life designed for at least 40000 hours.
4. For precise features, safe operation and low noise, each turbine is dynamically balanced while assembly.
5. Motor protection rating is IP44.
Speed Control
1. Smooth or step speed control with a thyristor or autotransformer speed controller.
2. Several fans may be connected to one speed controller provided that the total power and operating current do not exceed the rated speed controller parameters.
Operation Logic
1. Set the desired air temperature (set point of the thermostat) with the thermostat control knob. Set the required minimum impeller speed (air flow) with the speed control knob. The motor switches to maximum speed (maximum air flow) as the temperature reaches and exceeds the set temperature set point. The motor switches to the pre-set speed as the temperature drops down below the set temperature point.
2. To avoid the frequent motor switching, e.g. when the temperature in the supply air duct is equal to the threshold value, the switching delay time is activated.
There are two switch delay patterns for various cases:
1. The temperature sensor-based switch delay (U option): the motor switches to higher speed as the air temperature exceeds 2°C above the set thermostat set point. The motor revers to the pre-set lower speed as the air temperature drops below the thermostat set point. This pattern is used to keep air temperature to within 2°C. In this case the fan switches are rare.
2. The timer-based switch delay (U1 option): as the air temperature exceeds the set thermostat set point, the motor switches to higher speed and the switch delay timer is activated for 5 min. The motor reverts to lower speed as the air temperature drops down below the thermostat set point and only after the timer countdown.This pattern is used for exact air temperature control. The fan changes its speed more often as compared to the temperature sensor-based switch delay, however the minimum timer interval is 5 minutes.
