Medium Voltage Variable Frequency Converter AC Drive for HVAC
A compressor is a mechanical device that takes in a medium and
compresses it to a smaller volume. Compressors can either increase
or decrease a given mass to a lower or higher pressure. A
mechanical or electrical drive is typically connected to a pump
that is used to compress the medium.
Compressors have many everyday uses, such as:
· Air conditioners, (car, home)
· Air pumps
· Home and industrial refrigeration
· High pressure car washes
· Hydraulic compressors for industrial machines
· Air compressors for industrial manufacturing
Compressors are used by many industries that depend on the power of
compressed gas or fluid to power manufacturing processes of all
kinds.
There are several different compressor types:
· Rotary screw compressor
Two helical rotors force gas into a chamber that decreases in size,
thereby increasing the pressure of the gas. The screws in the
rotary screw compressor can be lubricated with oil or
non-lubricated. Oil-free compressors are used for gas that must
remain clean and uncontaminated. Rotary screw compressors are
typically sized from 30-200 horsepower.
· Reciprocating compressor
One or more pistons are moved inside a cylinder to increase the gas
pressure. This is similar to a combustion engine without the
ignition of fuel. Just like a car, the pistons generate much heat
so the reciprocating compressor is typically cooled by air or
water. Multi-stage reciprocating compressors pass the compressed
gas from one cylinder to another, increasing the pressure in each
stage. Most industrial compressors are multi-stage, ranging from
one to 500 or more horsepower.
· Centrifugal compressor
Centrifugal compressors speed up and compress gas via a rotor with
blades. Centrifugal force is used to force the air or gas to an
outer chamber under higher pressure. Centrifugal compressors are
designed to operate above 75-80% speed. Surging can occur below
these speeds. This makes the centrifugal compressor ideal for
continuous high duty operation.
Power range of G11 VFD
Voltage: 1140VAC (959VAC – 1311VAC)
Power: 45kw/60HP – 400kw/535HP
Specification of G11 VFD
Item | Specification |
Input frequency | 50/60Hz |
Output frequency | 0-400Hz |
Overload current | 150% rated current 1min., 180% 10 sec. |
Control mode | sensor-less vector control, V/F control |
Starting torque | 150% 0.5Hz |
Control precision | ±0.2% |
Torque precision | ±5% |
Setting frequency menthod | Plastic Extruder Machines, multi-step speed, simple PLC and PID. |
Output frequency resolution | 0.01Hz |
Frequency setting signal | 0~+10V; 2~+10V; 4~20mA, 0~20mA |
Protection function | Over voltage, under voltage, over load, relay, overheat speed
stall, grounding, instant power cut compensation( within 2 sec for
operation mode. Continue to operate after the power is available),
Charging protection( not to display when the dc voltage of main
circuit is less than 50v), up to 29 ways. |
Enclosure | IP20 |
Cooling mode | forced air cooling |
Vibration | Less than 0.2g for 20hz |
Ambient temperature / Humidity | -10 Degrees~+40 Degrees / 20~90%Rh (no condensation) |
Tips:
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.
