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HEATINC VENTILAtlNC AIR CONDITIONING GUIDE 1944
Table 1. Classification of Motors
Speed CharacTERISTICS
' Full Voltage l-----------------
Torque Curhrnt
Hp Range '
4
Type of
Application See Footnote*
1. Shunt
Direct
2. Compound
3. Series
Constant Speed Drives
I Normal j All Constant Normal
Constant or Variable
High
Variable. High
Normal All
Normal
Small
(ff) Fans and (c) centrifugal pumps
and centrifugal compressors
(&) (fi) (e) Redprocat ing pump9 and frequent or hand starting
(d) Fans direct con nected
4. Squirrel-Cage Constant General Purpose Normal Torque
Normal' 0.8-1.5. : times -
High 6-8 times
AU
5. Squirrel-Cage Constant Normal Torque
Normal 0.8-1.5
times
Normal
Medium
5-6`times Small
6. Squirrel-Cage High Torque
Poly
phase
7. Wound Rotor
8. Synchronous High Speed.
Constant
High 2-2.6
times.
Normal Medium 5-6 times Small
Constant High ' or 1-2.5 Variable times
Low
1--3 times with sec ondary control
AU
Constant
Normal
0.75-1.75 times '
Normal
Medium
5-7 times ~ Large
9. Synchronous Low Speed
Constant
Lew
0.3-0.4 times
Low
Medium
3--4 times Large
(a) Fans and (c) centrifugal pumps
and centrifugal compressors
(a) Fans and centri-- fugal pumps and centrifugal com pressors
(5) Reciprocating pumps
() and compressors started loaded
<p) Hoists (5) reciprocating.,
pumps and com pressors (e) and frequent (*)-or hand start
(a) Fans and cen trifugal pumps and centrifugal com pressors
(a) Reciprocating compressors .start ing unloaded.
Single
phase
10. Capacitor L Capacitor Fan
^Applications:.
Constant. Constant
High / . Normal
Normal Small - Normal . Small
'
[6) Pumps.and compressors
iff) Fans, centrifugal pumps
a. Drives having medium or low starting torque and Inertia (FFi?*) 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. accec.leSraitminiglatrotroqu(ea.) except where frequent or hand starting (large WR*) requires a higher starting and
d. Fans direct connected. '' Stoker drives.
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Current
CHAPTER 36. MOTORS AND MOTOR CONTROLS
Table 1. Classification of Motors--(Concluded)
------------------------------------- -
Type
Full Voltage'
Charac
teristics
Starting Torque
Starting Current
Hr . Range
Type op See Footnote*
12. Capacitor Start Constant High Induction Run
Single
13. Repulsion
phase
Induction
Constant High
14. Split. Phase -
Constant
and Adjust able
Normal
Normal Normal Normal
SraaU
() Fans
Fractional () pumps and
compressors
Medium Small
(a) Fans
(p) pumps and
compressors
Fractional
() Fans () pumps and
compressors
(d) fans--direct
Adjustable Speed Drives
Direct
15.. Shunt Field Adjustment
Constant
16. Shunt Armature . Variable Resistor
17. Variable Voltage Variable Control
formal formal Normal
'formal formal Normal
&11 AU AU
a) Fans and (e) centrifugal pumps
a) Fans and V) centrifugal pumps
(d) Fans and . centrifugal pumps
PHASE
18. Squirrel-Cage
. High Slip. Transformer Adjustment
Variable
19. Squirrel-Cage
Constant
Separate Wind- Multi-
ing or Regrouped Speed
Pols
20. Wound Rotor, External Secondary Resistance
Variable
Normal
Normal or High
High
Normal
Normal or Low
Low.
Medium SmaU
AU
AU
(o) Fans
() Fans () pumps and (c) compressors
(6) centrifugal pumps and compressors
21. Repulsion
Variable Hlgfi
Phase
?*>, Capacitor Low Torque Tapped Winding
23. Capacitor Low Torque Trans former Adjust ment
Variable Two Speed
Variable
24. Sollt Phase
Constant
Regrouped Poles
Low .Low
Normal
Normal Normal Low Normal
Low and () Fans--centrifugal
Fractional
pumps
() compressors
Fractional (d) Fans, direct
Fractional (d) Fans
Fractional (d) Fans
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