NEMA, IEC or Laminated Frames / 1/3 to 2,250 HP
ABB Baldor-Reliance variable speed motors are AC motors designed to run on a variable speed drive, holding torque across the speed range. The ABB Baldor-Reliance NEMA range covers V*S Master inverter and vector duty motors and RPM AC laminated frame motors for extruders, winders, machine tools, test stands, conveyors, cranes and hoists.
A standard motor run on a drive loses cooling at low speed and can suffer insulation and bearing damage from the drive output. Variable speed motors are designed for it, with an inverter duty insulation system, cooling that does not depend on shaft speed, and shaft grounding. There are two families:
RPM AC motors are also used to replace DC motors on existing variable speed machinery. They pair with an AC variable speed drive. For high efficiency on variable torque loads such as fans and pumps, see EC Titanium.
| Specification | V*S Master (inverter / vector duty) | RPM AC (laminated frame) |
|---|---|---|
| Power range | 1/3-300 HP (0.25-224 kW); custom 1/2-500 HP; severe duty vector 1-50 HP | 1-2,250 HP; extruder duty 25-1,000 HP |
| Frames | NEMA 56-449T | Square laminated, 280-5800 (NEMA or IEC mounting dimensions) |
| Constant torque range | Zero to base speed, full load torque (vector duty); TEFC Class B rise over 4:1 | 1000:1 standard; continuous to zero speed |
| Constant horsepower | To 1.5 × base speed | 2:1 above base speed on most ratings |
| Base speeds | 900, 1200, 1800 rpm | Any base speed to suit the application |
| Enclosures | TENV (small ratings), TEFC and TEBC (large ratings) | DPFV, TEBC, TENV, TEFC, TEAO; IP44-IP56 |
| Insulation | Inverter duty system exceeding NEMA MG1 Part 31; Class F or H | Class H, corona-free |
| Encoder | Mounting provisions standard | Mounting provisions standard |
| Bearings / grounding | See datasheet | Lubricated-for-life PLS system (280-5800); insulated bearings on larger frames; shaft grounding standard |
| Overload | See datasheet | Up to 200% torque for 1 minute, zero to base speed |
| Service factor | 1.0 | 1.0 [confirm] |
For technical information, brochures and further product details, visit our downloads page.
A variable speed motor is an AC motor designed to run on a variable speed drive. It has an insulation system that withstands drive output, cooling that works at low speed, and usually shaft grounding to protect the bearings. A standard motor may be drive-rated, but over a narrower speed range.
Inverter duty motors are designed for open-loop drive control over a limited constant torque speed range. Vector duty motors are built for closed-loop vector control with an encoder, and deliver full rated torque continuously from zero to base speed.
RPM AC is ABB Baldor-Reliance’s laminated frame AC motor. The square laminated steel frame gives high power density, up to three frame sizes smaller than a traditional motor, with a 1000:1 constant torque speed range as standard and ratings to 2,250 HP.
Yes. RPM AC motors are used to replace DC motors on extruders, winders and other constant torque machines. They give similar low-speed torque and speed control on an AC drive, without brushes or commutator maintenance.
It means the motor can deliver full rated torque continuously at speeds down to one thousandth of base speed, for example below 2 rpm on a 1750 rpm base speed motor, without overheating.
For open-loop speed control, no. For precise speed or position control, or full torque at very low speeds, closed-loop vector control with an encoder is used. V*S Master and RPM AC motors have encoder mounting provisions as standard.
Send us the catalogue number from the motor nameplate, or the horsepower, base speed, speed range, torque requirement, frame, voltage and enclosure, for a quote. Call 01924 411921 or email sales@betech.co.uk.
