Document 6R9gzdXQ796NaMVy2kno0zRZ6

Heating Ventilating Air Conditioning Guide 1939 CURRENT TYPE Table 1. Classification of Motors Speed Charac teristics FuU. VOLTAOE Starting Torque Starting Current Hp Range Ttpb op ,, Application See Footnote* 1. Shunt Direct 2. Compound Constant Speed Drives Constant Medium Medium All Constant High or Variable Medium All (a) Fans and (c) Centrifugal Pumps ' (6) _ (c) (e) Recipro cating Pumps and frequent orhand starting 3. Series Variable High Medium Small (d) Fans direct connected Poly phase 4. Squirrel Cage Constant Normal High All General Purpose 6-8 Times (a) Fans and (c) Centrifugal Pumps 5. Squirrel Cage Constant Normal Medium Medium (a) Fans and Medium Torque 5-6 Times Small Centrifugal Pumps 6. Squirrel Cage High Torque Constant High Medium Medium (4) Reciprocating 5-6 Times Small Pumps () and Compressors started loaded 7. Automatic Start Constant High High Torque Low 3 Times Medium (4) Reciprocating Pumps () and Compressors started- loaded 8. Slip Ring Constant High Wound Rotor Low All 1-3 Times with sec ondary control (a) and Hoists (i) Reciprocating Pumps (c) and Frequent (e) or Hand Start 9. Synchronous High Speed Constant Medium Medium Medium (o) Fans and Cen \ 5-7 Times Large trifugal Pumps 10. Synchronous Low Speed Constant Low Low Medium (o) Reciprocating 3-4 Times Large Compressors Start ing Unloaded Single 11. Capacitor PHASE Constant High Normal Medium (6) Pumps and Small Compressors * "Applications: a. Drives having medium or low starting torque and Inertia (WR*) such as fans and centrifugal pumps or reciprocating pumps and compressors started unloaded. b. Drives having high starting torques, such as reciprocating pumps and compressors started loaded. c. Similar to (o) except where frequent or hand starting (large WR*) requires a higher starting and accelerating torque. d. Fans direct connected. e. Stoker drives. 724 Chapter 38. Motors and Controls Current Table 1. Classification of Motors--(Continued) . TYPE Charac teristics Fuu, Voltage &TAR7TN0 Torque Starting Current Hp Range Ttpb op . Application See Footnote* Single phase 12. Capacitor Fan Constant High Medium Medium (a) Fans--belted Small 13; Capacitor Fan Constant Low Medium Medium (<f) Fans--direct Small 14. Capacitor Start Constant Any Induction Run Medium Medium (a) Fans Small (4) Pumps and Compressors 15. Repulsion Induction Constant High Medium Medium (a) Fans Small (4) Pumps and Compressors 16. Repulsion Start Constant High Induction Run Medium Medium (a) Fans Small (b) Pumps and Compressors 17. Split Phase Constant Medium Medium Frac and tional Adjust- table (a) Fans (4) Pumps and Compressors Adjustable Speed Drives 18. Shunt Field Adjustment Constant Medium Medium All Direct 19. Shunt Armature Variable Medium Medium All Resistor (o) Fans and (e) Centrifugal Pumps (a) Fans and (e) Centrifugal Pumps Poly phase 20. Squirrel Cage Variable Medium Medium Medium (a) Fans High Slip, Small Tapped Winding 21. Squirrel Cage Variable High Slip, Trans former Adjust ment Medium Medium Medium Small (a) Fans 22. Squirrel Cage Constant Medium Low Separate Wind Multi- or High ing or Regrouped Speed Poles All (a) Fans (4) Pumps and (e) Compressors