Portable load banks typically offer manual control with toggle switches, so controlling multiple units from a single system significantly reduces manpower requirements, especially when testing multiple UPSs, and improves workflow.
The Avtron Sigma Control System, with advanced microprocessor-based control and instrumentation, is specifically developed for load bank applications. Every Sigma-controlled load bank has its own embedded control unit complete with high-accuracy voltage and current transformers, all located within the load bank. The instrumentation digitally processes raw data with high-speed sampling, providing full measurements and high update rates.
The Avtron Sigma 2 Control System is built on 20 years of power testing and control experience spanning a global installed base of more than 1500 load banks. Networking any combination of resistive, inductive and capacitive Avtron Sigma-controlled Load Banks provides the flexibility to achieve power testing capacities of more than 50 MW.
The Avtron Sigma 2 Intelligent Handheld Terminal (IHT) is the control interface for a range of load bank functions.
Before testing, for example, it automatically detects power supply voltage, frequency and phases, and phase rotation to verify the supply connection. A technician can set and verify supply details any time using the Supply on Test display. Besides supply ratings, the Avtron Sigma 2 IHT calculates rated line current and kilowatts. A load correction facility compensates for supply voltage drop.
Using an integrated test editor, a technician can easily set up load steps, including percent load, power factor and time. Entering supply-on-test capacity parameters, for example, determines load control, enables the terminal to protect the supply from accidental overloading, and gives a technician the choice of applying load either in percent load, or in kW and kVA. Fully adjustable leading and lagging power factor control ranges from 0.00 to 1.00.
Automatic load control provides up to 16 timed load steps, including manual override and cyclic testing. The Avtron Sigma 2 IHT permanently retains automatic test and system options. A technician also can manually control load by selecting such parameters as percent load, or kW, kVA and power factor, eliminating the need to calculate kW and kVAR. For transient-response testing, voltage and frequency of the last load change are captured and displayed on a dynamic graph, including maximum and minimum data.
The Avtron Sigma 2 IHT can operate load banks from distances of up to 3,000 feet. Multi-language support includes English, French, German, Spanish and Italian.