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HEATINC VENTILATING AIR CONDITIONING CUIDE 1940
CUBRENT
Table 1. Classification of Motors
type
Speed
Charac teristic!}
Full Voltage
Starting Torque
Starting Current
Hp Range
Ttpb OP
Application See Footnote*
1. Shunt
Direct
2. Compound
3. Series
Constant Speed Drives Constant Medium Medium All
Constant Tigh Dr Variable
Variable High
Vledium Ml Vledium Small
a) Fans and c) Centrifugal 5umps
(c) (e) Recipro:ating Pumps and freijuentorhand starting
[d) Fans direct connected
Poly
phase
4. Squirrel Cage Constant Normal General Purpose
High
All
6-8 Times
(o) Fans and (c) Centrifugal
Pumps
5. Squirrel Cage Constant Normal Medium Torque
6. Squirrel Cage. Constant High High Torque
Medium Medium (o) Fans and 5-6 Times Small Centrifugal Pumps
Medium Medium (ft) Reciprocating
5-6 Times Small
Pumps (e) and Compressors
started loaded
7. Automatic Start Constant High High Torque
Low 3 Times
Medium
(ft) Reciprocating
Pumps (e) and Compressors
started loaded
8. Slip Ring Wound Rotor
9. Synchronous High Speed
10. Synchronous Low Speed
Constant High
Low
All '
1-3 Times
with sec
ondary
control
() and Hoists () Reciprocating
Pumps (c) and Frequent (e) or Hand Start
Constant Medium
Medium Medium 5-7 Timess Large
(a) Fans and Cen trifugal Pumps
Constant Low
Low
Medium (a) Reciprocating
3-4 Time.> Large Compressors start
ing unloaded
Single
phase
11. Capacitor
Constant High
Normal Medium (6) Pumps and Small Compressors
v a. Drives having medium or low starting torque and inertia (PFR*) such as fans and centrifugal pumps or reciDprroivceastinhgavpiunmg phsigahnsdtacortminpgretsosroqrusesst,asrtuecdh uansloraedceipdr.ocating pumps and compressors started loaded.
c. Similar to (<*) except where frequent or hand starting (large WR*) requires a higher starting and
accelerating torque.' d. Fans direct connected. e. Stoker drives.
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CHAPTER 39. MOTORS AND CONTROLS
Current
Table 1. Classification of Motors--(Continued)
TYPE
Speed Charac
teristics
Full Voltage
Starting Torque
Starting Current
I j
Hp Range
Application See Footnote*
Single PHASE
12. Capacitor Fan Constant High
Medium Medium (a) Fans--belted Small
13. Capacitor Fan Constant Low
Medium Medium (d) Fans;--direct Small
14. Capacitor Start Induction Run
15. Repulsion Induction
16. Repulsion Start Induction Run
17. Split Phase
Constant Any
Constant High
Constant High
Constant Medium and Adjusttable
Medium Medium () Fans Small () Pumps and
Compressors
Medium Medium (a) Fans Small (A) Pumps and
Compressors
Medium Medium (a) Fans Small (ft) Pumps and
Compressors
Medium Frac tional
(a) Fans (A) Pumps and Compressors
Adjustable Speed Drives
Direct
18. Shunt Field Adjustment
Constant Medium Medium All
19. Shunt Armature Variable Resistor
Vledium
Medium All
[a) Fans and [e) Centrifugal Pumps
'a) Fans and fi) Centrifugal ?umps
Poly
phase
20. Squirrel Cage Variable High Slip, Tapped Winding
Medium
Medium Medium Small
a) Fans
21. Squirrel Cage 1Variable High Slip, Trans
former Adjust ment
Medium
Medium Medium <small
a) Fans
5'2. Squirrel Cage < 'onstant 1 Medium ] -X)W Separate Wind- ] Multi- c r High ingor Regrouped 5Speed Poles
iMl
a) Fans ft) Pumps and c) Compressors
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