greendriv

Dust on any electronic devices may cause mal-function or even failure. Dust absorbs moisture, which also contributes to failure. Periodically spraying air through the heat sink fan is a good PM measure. Discharging compressed air into a drive is a feasible option in some environments. But unfortunately typical plant air contains oil and water. To use compressed air for cooling, you must use air which is oil-free and dry. Otherwise you will do more harm than good.

How to maintain a frequency inverter (AC drive, variable frequency drive, VSD)? Is it a complex job? Challenging? Maintaining a frequency inverter (AC drive) is easier than you might think. By integrating some simple, logical steps into your preventative maintenance program, you can ensure that the drives provide many years of trouble-free service.

Gennerally up to 70% of the electricity consumed by injection molding machine is never used in the molding process. It's wasted. The wasted electricity (energy) by injection molding machine brings some problems: heating the machine's hydraulic oil, noise, and wear and tear on the machine's hydraulic system. The hydraulic oil in an injection molding machine gets hot, and would cook if not for a cooling tower.

40% of all energy consumed! The savings potential in heating, ventilation and air conditioning (HVAC) applictions is very, very big. And the rising energy cost and concerns about the CO2 levels and global warming make us to choose a better method. But the most effective way for saving energy in the building, to be exact, in HVAC applictions, is applying frequency inverters (variable speed drives).

In big motors, a slip ring with brush can be used to provide a bypass path for the bearing currents. Alternatively isolated bearings can be used. The 2.5 kHz and 5 kHz CSFs cause less motor bearing problems than caused by Carrier Switching Frequencies (CSF) at 20 kHz. Shorter cables are recommended at the higher Carrier Switching Frequency (CSF) of 20 kHz. The minimum CSF for synchronize tracking of multiple conveyors is 8 kHz.

The output voltage of a Pulse Width Modulation (PWM) variable frequency drive (VFD) consists of a train of pulses switched at the carrier frequency. Because of the rapid rise time of these pulses, transmission line effects of the cable between frequency inverter (vfd) and the motor must be considered. Since the transmission-line impedance of the cable and motor are different, pulses tend to reflect back from the motor terminals into the cable.

Reducing energy cost is well known for ac drives in motor control. But ac drives (variable speed drives) do more than we thought, including, but not limited: 1. reduce fan noise and duct rumble, thus reducing tenant complaints. 2. reduce amps during motor starting, lowering demand charges; That's another significant part of the electric bill. 3. less expensive to maintain, which is better than mechanical controls in the industry.

Medium voltage (3kv, 3.3kv, 6kv, 6.6kv, 10kv, 11kv and even higher) variable speed drives (frequency inverters) are widely applied in many fields in the industry.