Back to top

ST/SN Series AC Synchronous Motors

ST and SN Series synchronous motors provide high performance in three frame sizes, NEMA 23, 34 and 42 (60, 90 and 110 mm). Resistor-capacitor kits are also available. These motors are driven economically from standard AC line voltage and the synchronous speed is related to the line frequency.

Limited availability outside North America
ST/SN AC Synchronmotoren


  • ST models: NEMA 23 (60 mm), three stack length options with torque ratings to 131 N-cm (185 oz-in)
  • SN3 models: NEMA 34 (90 mm), three stack lengths with torque ratings from 198 to 636 N-cm (280 to 900 oz-in)
  • SN4 models: NEMA 42 (110 mm), three stack lengths with torque ratings from 500 to 1059 N-cm (715 to 1500 oz-in)
  • All models offer flying lead, terminal box, connector and shaft extension options
  • 72 rpm motor speed (with 60 Hz voltage)
  • Constant speed does not vary with load
  • 120 volt AC models
  • Fast starting, stopping and reversing
  • Can be stalled indefinitely without overheating
  • Standard connections include leaded, terminal box, MS connectors, rear shaft


Model NEMA Frame Sizes Rated Torque (oz-in) Max Load Inertia (oz-in-s1) Standard Options
ST Series 23 4 80-185 0.02 - 0.15 L, T, MS, RS
SN3 Series 34 4 280-900 0.19 - 0.46 L, T, MS, RS
SN4 Series 42 3 715-1,500 0.32 - 0.69 L, T, MS, RS

Get Started

Count on Kollmorgen support to help you design and build a successful machine and keep it reliably productive, anywhere in the world. Our co-engineering experts will work with you to tailor a perfect-fit solution for your motion requirements.

Talk to a motion expert
Title Language(s) Date Size
pdfKollmorgen EU Declaration of Conformity PowerPac K-N-SN English 25 May 2017 114.53 KB Copy URL
Title Language(s) Date Size
Kollmorgen Automation and Motion Control English 14 Jun 2021 15.53 MB Copy URL
Stepper and Synchronous Motors Catalog EN Rev C English 19 Feb 2014 7.96 MB Copy URL
Title Language(s) Date Size
pdfSuperior Stepper Connection Diagrams EN.pdf English 29 Sep 2011 142.25 KB Copy URL
pdfSuperior Synchronous Connection Diagrams en US.pdf English 29 Sep 2011 2.05 MB Copy URL
Trade Compliance Kollmorgen is committed to sourcing components and materials from companies that share our values regarding respect for human rights, integrity and environmental responsibility. Kollmorgen is also...
Normen und Richtlinien [toc] Allgemeines Struktur des Normenwesens am Beispiel der EN ISO 12100 Europäische Richtlinien New Legislative Framework Blue Guide: Leitfaden für die Umsetzung der...
Standards and Directives [toc] General Structures of standards with EN ISO 12100 as an example ISO Standards Safety of Machinery — General Principles for Design ISO 12100:2010 UL Standards...
Title Language(s) Date Size
Blue Guide English, German 29 Jun 2022 Copy URL