Variable Speed Controls Sensorless Vector Drive for HVAC with Low
Take central air conditioning system for example.
Central air conditioning system consists of chillers, cooling
systems, chilled water system, cooling tower fan coil system and
the composition of the chiller refrigerant compressed by the
compressor into the liquid evacuation evaporator heat exchange with
chilled water, chilled water cooling, chilled water pump chilled
water to each fan coil cooling wind, the cold air from the fan
blowing up cooling purposes. The evaporated refrigerant in the
condenser releases heat, and cooling circulating water heat
exchange, heat from the cooling water pump will bring the cooling
water pump to the cooling tower of its conduct by the spray cooling
tower fans, and between the atmosphere heat exchanger, the heat
emitted to the atmosphere.
- Quick response
- Low noise
- Terminals control
Features of 303 series HVAC application
flexible input methods
1. Speed input-Take running speed of the motor as the control
Speed input consists of the main speed input, auxiliary speed input
and inching speed input, etc. The actual effective combined speed
input can be either of the three or the combination of either of
2. Torque input-Take output torque of the motor as the control
Set output torque of the motor directly, particularly suited to
application fields requiring tension control.
Terminal-Peripheral equipment control
Control start/stop with the contact or button to simply realize the
automation control of the entire equipment system.
S curve acceleration/deceleration mode
S curve acceleration/deceleration can reduce impact to the machine
at start/stop time, and suitable for the start/stop process for
loads of handling and transmission categories.
Power range of 303 VFD
Voltage: 3 phase 380VAC(304VAC – 460VAC)
Power: 0.75kw/1HP – 400kw/535HP
Specification of 303 VFD
150% rated current 1min., 180% 2 sec.
sensor-less vector control(SVC), V/F control
150% 1Hz (SVC 150% 0.5Hz)
Given Frequency Resolution
Digital given: 0.01Hz, analog given: 0.05Hz
Keyboard, control terminal (two-line control, three-line control),
Output Voltage self-adjustment
When AVR function is enabled, the input voltage changes, while the
output voltage almost remains unchanged
Frequency setting signal
Short circuit, overcurrent, overload, overvoltage, undervoltage,
default phase, overheating, and external fault, etc.
forced air cooling
Less than 0.5g
Ambient temperature / Humidity
-10 Degrees~+40 Degrees / 20~90%Rh (no condensation)
A variable-frequency drive (VFD) is a system for controlling the
rotational speed of an alternating current (AC) electric motor by
controlling the frequency of the electrical power supplied to the
motor. A variable frequency drive is a specific type of
adjustable-speed drive. Variable-frequency drives are also known as
adjustable-frequency drives (AFD), variable-speed drives (VSD), AC
drives, microdrives or inverter drives. Since the voltage is varied
along with frequency, these are sometimes also called VVVF
(variable voltage variable frequency) drives.