The contract was to supply the controls for the new bridle and transport drives at the entry section of one of their annealing and pickling lines. This is the largest of a number of projects where Control Techniques’ drives are replacing older drives and a total of 19 drives have been supplied for the new entry section. The drive system panel suite was designed, built and commissioned by Control Techniques (Pty) SA. The scope of the system is to control 16 wringer roll motors, each 7 HP (5.5 kW), 4-pole, 525 volt geared motors, plus two 150 HP (110 kW), 525 volt bridle motors and a 40 HP (30 kW) exhaust fan.
Each of the ringer roll motors is controlled by a 10 HP (7.5 kW) panel-mounted AC drive and the larger bridle motors have 150 HP (110 kW) modular Unidrive units with regenerative mode for accuracy of tension control and maximum efficiency saving. Each drive is fitted with additional option modules for Profibus communications, as well as a powerful second processor module for distributed control.
A replacement for a complex and unreliable control system for the Static Cut-off machine has dramatically improved machine reliability and throughput at the works. The plant produces large steel pipes up to 24’’ in diameter.
The existing system was obsolete and unreliable, with no support, comments Dave Watt, Senior Electrical Project Engineer at the plant with responsibility for the project. “The reliability was poor with the software and documentation difficult to follow.
The overall plant efficiency is reliant on the operation of the Static Cut-Off machine which provides test samples of the finished pipe product for QA (Quality Assurance) purposes. So a replacement was needed urgently, and a solution featuring drives and servos from Control Techniques was recommended.
A leading manufacturer of sheet metal working machines, has standardized on AC drives from Control Techniques!
Unidrive AC drives are the drives of choice for a variety of applications, from open-loop control for material handling, closed loop control for slitting lines and servo control for high-precision feeding and cutting. As part of an upgrading process to meet market demands and produce a more competitive product the manufacturer switched to AC drives for all of its re-designed cut-to-length machines, straighteners and slitting lines. Unidrive AC drives met their requirements in every way with drives ranging from 1 HP (0.75 kW) right up to up to 2,000 HP (1.5 MW)!
The manufacturer is using the versatility of the Unidrive AC drives to the full, with drives being applied in different modes and using the plug-in SM applications modules to provide on the spot precision control and maximum dynamic performance to achieve the best possible control of speed, tension or positioning precision, depending on the task at hand. On-board programming has minimized and in some cases eliminated the use of additional PLCs. This has meant control cubicles can be reduced in size, enabling the whole machine size and footprint to be minimized. SyPTPro programming software allows the company to carry out its own programming reducing project time and start-up time.
For example the manufacturer utilizes Unidrive AC drives to provide servo positioning control on press feeding units and on cut-to- length lines, in closed loop AC mode for slitting lines and many in open-loop AC control mode on applications from conveyors to other materials handling tasks. In addition, the manufacturer likes the fact that each drive can, if required, be fitted with communication modules allowing communications with standard PLC and HMI systems, meeting the most demanding end-user specifications.