Low- and medium-voltage motor control equipment specialist CHI Control Components is unveiling a group of new soft starters and variable-speed drives, designed to make the management and maintenance of motor applications easier.
CHI Control Components marketing director Rob Hare says that the company’s new soft starter, the EMX-3, has a special feature called XLR-8, which gives the operator different starting and stopping profiles for various motor applications.
“The distinguishing factor of this new soft starter is that with its XLR-8 feature it takes most of the guesswork out of the application of the soft starter.
The XLR-8 is different from other soft starters because it speeds up or stops the motor in a controlled manner. By using intuitive starting, which allows the soft starter to apply the last starting parameters on the latest start, the XLR-8 accelerates the motor in the most favourable way for its particular application.
This means that the more times the motor gets started, the better the start becomes for the particular application,” Hare explains.
The XLR-8 feature allows the motor to be stopped in a linear current way, or in a linear time way. The difference is that the motor can be stopped by ramping the current down, or by programming the EMX-3 to stop the motor over a certain period.
The soft starter intelligence also allows it to assume variables in the adjustability of the device that is being started, with the operator only required to input a few criteria, such as the current used on the motor, while the XLR-8 feature does the rest.
The soft starters are available from 23 A to 1600 A and are rated for 380-V to 690-V applications.
“The soft starter is not rated by kilowatt, but rather by a current rating so that the application can be sized as needed,” Hare comments.
The soft starter comes with an event logging and performance monitoring feature as well. Should an event occur, such as a trip-out on an overload relay, the event log feature will record this, allowing the operator to determine the fault that caused the trip. The information can be stored about 99 times and is tamper-proof.
The soft starter also has an extensive motor protection relay. Depending on the application, resistance thermal detection devices (RTDs) can be placed on the hot spots of an electric motor, and are used to measure the temperature in the motor, sending this information to the overload relay. The overload relay then manipulates the adjustability and the tripping curves in the starter, so that the motor will always have a favourable trip characteristic.
“The RTDs monitor the heat in the motor, and put the information into the algorithm of the overload relay, which will judge the thermal capacity left in the motor, before shutting down. The EMX-3 also has an alarm system, which will warn the operator of imminent tripping in the motor,” Hare comments.
The EMX-3 can be operated with a removable, multilingual keypad. This means that the starter can be set up and the keypad removed, so that tampering cannot occur.
Hare says that the EMX-3 soft starter will be launched in May 2008, and has been tested on Beta sites around the world, in as many applications as possible.
“Because of South Africa’s 525-V voltage, which is exclusive to the country, the soft starters also needed to be tested locally. It is for this reason that two EMX-3s have been tested on a crusher and a conveyor in the Rustenburg area. They have been in operation for 18 months, and are performing very well,” Hare says.
New Zealand soft starter specialist Aucom, which also developed the XLR-8 feature on the soft starter, manufactures the EMX-3. CHI Control is the local distributor of the EMX-3 soft starter range.
CHI Control is also launching a new variable-speed drive from Finish variable-speed drive manufacturer Vacon.
CHI Control markets variable-speed drives up to 690 V, and stocks the parts accordingly.
“We can control motors of up to 3 MW, with the largest motors in South Africa currently at 1,2 MW. Because of the country’s 525-V power supply, the variable-speed drives are rated to manage up to 690 V, leaving a fair amount of headroom, should a power spike occur,” Hare explains.
The Vacon variable-speed drives are also programmed using a keypad which can be removed and used to programme additional variable-speed drives with the same parameters.
Hare says that the variable-speed drives from CHI Control differ from other variable-speed drives, in that the Vacon range is manufactured with standard line filters already installed.
Line filters trap harmonics and disturbances coming from the power distribution system, smoothing out the power feed and are usually optional on variable-speed drives.
The variable-speed drives also have an intuitive intelligence capability, much like the soft starters. The variable-speed drive will programme itself according to the last start, and should the current start not be in line with the previous start’s parameters, the variable-speed drive can be programmed to shut the system down, if so desired.
The variable-speed drive can also be programmed to abort an operation, such as a crusher, if the start is not consistent with the previous start, which could potentially save a company from total equipment breakdown.
It also has analogue and digital inputs and outputs, so that the drive’s performance can be monitored.
CHI Control will be launching a new range of micro variable-speed drives from Vacon, in July. The system will be based completely on customers’ requirements for their specific applications, allowing them to build up their own variable-speed drives, with the versatility of adding multiple types of application software that can be used.
“The option on the microdrives is that customers will only pay for what they get,” Hare explains.
The versatility of the micro variable- speed drive means that customers can buy variable-speed drives suited to their particular operations.