These VFDs provide flexible motor control, energy savings
A new line of VF1A Doesa variable frequency drives (VFDs; photo) offer versatile control and efficient operation of electrical motors for a wide range of applications. VF1A Doesa VFDs are suitable for speed control of variable- and constant-torque applications, ranging from fans and pumps to specialized 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 a.c. 400 V (with an allowable input voltage range of 380–480 V a.c.), and the VFDs come in 14 models with a capacity range of up to 139 A. Each VFD is quadruple rated for varying duties — normal or heavy overload, and mild (40°C) or high (50°C) temperatures — so users can minimize the number of models needed to handle a wide range of applications. Other 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 fulfills functional safety standard requirements while eliminating the need for external circuit breakers required by conventional VFDs. — IDEC Corp., Sunnyvale, Calif.