VFDs provides flexible motor control and energy savings

Control and efficiency

VFDs are used to control the speed and torque of AC motors so users can optimise system performance by running equipment at just the speed required to meet the demand of the load. Furthermore, VFDs are configurable to accelerate and decelerate to commanded speed smoothly, reducing the wear and tear on associated mechanical components. Among the greatest of VFD benefits is the energy savings realised by running a motor at any speed below maximum, so long as the equipment needs are met.

Control options

IDEC VF1A Doesa VFDs are suitable for speed control of variable and constant torque applications ranging from fans and pumps to specialised equipment. The VFD is capable of driving an induction motor (IM) or a permanent magnet synchronous motor (PMSM). IMs can be driven in open loop or closed loop, while PMSMs can be driven in open loop only

The product family features a compact form factor in a UL open-type construction, with nickel- and tin-plated bus bars and conformal coatings for corrosion protection. The VFD is designed for a long operating life and provides a maintenance alarm signal.

Electrical input is nominally rated as three-phase low voltage AC 400V (with an allowable input voltage range of 380-480V AC), and the VFDs come in 14 models with a capacity range of up to 139A. Each VFD is quadruple rated for varying duties – normal or heavy overload, and mild 40^oC or high 50^oC temperatures – so users can minimise the number of models needed to handle a wide range of applications.

Other advanced functionality includes control of mechanical brakes, a built-in braking transistor, regeneration avoidance, and low-voltage ride through. Safe torque off (STO) capability ensures the VFD fulfils functional safety standard requirements while eliminating the need for external circuit breakers required by conventional VFDs.

Logic programming with 55 functions, different calculations and sequences, and fast processing intervals lets designers eliminate other small controllers and adapt the VFD to meet special requirements. The logic is configured via easy-to-use graphical software, enabling users to create customised automation applications of up to 200 steps, including PID control. Online logic, value, and trace monitoring helps users optimise and diagnose applications. Password protection is included.

The VFD also includes seven digital inputs, two analogue inputs, three digital outputs, and two analogue outputs for added control functionality. A standard option port and RS-485 terminals are included, and the VFD accepts removable terminal cards for standard, 5V, and 12V/15V operation. Optional communication cards are available for simple integration of the VFD with PLCs and other intelligent devices.

An on-board keypad provides convenient status and diagnostic monitoring, along with local configuration and control capability. An optional external keypad makes it easy to set and save parameters in a convenient location – using a PC and software if desired – and then later connect this keypad locally at the VFD for downloading the configuration.

The IDEC portfolio of VF1A Doesa VFDs provide cost-effective, high-performance control for a wide variety of motor applications. As with all its products, IDEC offers free tech support for the VFDs, with no service or support contract required.