Brochure

160 www.usmotors.co
m
†
All marks shown within this document are properties o
f
their respective owners.
T
ERM
S
&
CO
NDITI
O
N
S
T
ERMIN
O
L
OGY
GU
ID
E
M
O
T
O
R
S
ELE
C
TI
O
N
GU
ID
E
INDE
X
TERMINOLOGY
GUIDE
E
nclosure
(
Encl
)
. The motor
’
s housin
g
. T
y
pes:
O
p
en
.
Ventilation openin
g
s in the shell and
/
or end
s
hields which permit passa
g
e o
f
external air over and
around the windin
g
s of the motor. Used indoors, in fairl
y
c
l
ea
n l
oca
ti
o
n
s
.
Open Air Over
(
OAO
).
M
o
t
o
r
s
int
e
n
ded
fo
r
fa
n
a
n
d
b
l
o
w
e
r
se
rvi
ce
. M
us
t
be
l
oca
t
ed
in th
e
a
ir
s
tr
ea
m t
o
p
rovide motor coolin
g
.
Open Drip-Proof
(
ODP
).
V
en
t
i
l
a
tion ope
n
in
g
s in end
s
hields and shell placed so drops o
f
liquid
f
allin
g
within
an an
g
le of 15° from vertical will not touch
the windin
g
s.

T
otall
y
Enclosed
(
TE
).
N
o
v
en
t
i
l
a
tion ope
n
in
g
s in motor
h
ousin
g
(
but not airti
g
ht
)
. Used in l
o
ca
ti
o
n
s
whi
c
h
a
r
e
dirt
y
, damp, oil
y
, etc. Includes
:
-
T
otall
y
Enclosed, Fan-Cooled
(
TEFC
).
I
n
c
l
udes
a
n
e
xternal
f
an, in a protective shroud, to blow coolin
g
air
o
v
e
r th
e
m
o
t
o
r fr
a
m
e
.
-
T
otall
y
Enclosed, Non-Ventilated
(
TENV
).
D
e
p
ends
on convection air
f
or coolin
g
.
-
T
otall
y
Enclosed, Air Over
(
TEAO
).
D
e
p
ends on
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avoid overheatin
g
, these motors must not be used in
applications where there is no air over.
Hazardous Location
.
A totall
y
enclosed motor d
e
s
i
g
ned
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to escape.
Full-Load Amps
(
F
/
L Amps
).
Lin
e
cu
r
r
ent drawn b
y
a motor when operatin
g
at rated load and vol
t
age
.
S
hown on motor nameplate alon
g
with service fact
o
r
amps if other than 1.0. Important for proper wire size
se
l
ec
ti
o
n
a
n
d
m
o
t
o
r
s
t
a
rt
e
r h
ea
t
e
r
a
n
d
o
v
e
r
cu
rr
e
nt
p
rotector s
e
lec
ti
o
n.
Frame
.
Usuall
y
re
f
ers to the NEMA s
y
stem o
f
standardized
motor mountin
g
dimensions, which
f
acilitates replacement.
H
ertz
(
Hz
)
. Frequenc
y
, in c
y
cles per second, of AC pow
er
;
u
suall
y
60 Hz in USA, 50 Hz overseas.
Horsepower
(
HP
).
The unit o
f
output power usuall
y
applied to electric motors in North America.
O
ne
h
orsepower is equiv
a
l
ent to 746 watts. Motor output power
c
an also be rated in terms o
f
watts. A
9
watt motor is
0
.012 or 1
/
80 horsepower.
M
otor S
p
eeds
S
y
nchronous
.
The theoretical maximum speed at which
an induction-t
y
pe motor can operate.
Syn
c
hr
o
nous
s
peed is determined b
y
the power line fr
e
q
u
en
cy
and
motor desi
g
n
(
number of poles
)
, and can be cal
cu
lat
ed
usin
g
the formula
:
R
PM =
Frequency in Hz x 120
qy
No. o
f
poles
Full-load
.
The nominal speed at which an i
n
duc
ti
o
n
motor operates under rated input and load co
n
di
ti
o
n
s
.
This will alwa
y
s be less than the s
yn
c
hr
o
n
ous speed
and will var
y
d
e
p
en
d
in
g
on the ratin
g
and characteristics
of the particular motor. For e
x
am
p
le, four pole 60 Hz
fr
ac
ti
o
n
a
l h
o
r
se
po
w
er
mo
tors have a s
yn
c
hr
o
n
ous speed
o
f
1800 RPM, a nom
i
n
al
f
ull load speed
(
as shown on the
nameplate
)
o
f
1725 RPM, and an actual
f
ull load speed
t
yp
i
ca
ll
y
ran
g
in
g
f
rom 1715 to 1735 RPM.
M
otor T
y
pes
.
Except where noted all t
y
pes require si
n
g
le
p
hase A
C
power.
Shaded
p
ole
.
Low startin
g
torque, low cost. Usuall
y
used in direct drive fans and blowers, and in small pumps.

P
ermanent split capacitor
(
PSC
).
P
e
r
fo
r
mance
and applications similar to shaded pole but more
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c
apabilities
.
Split phase start-induction run
(
or simpl
y
split
p
hase
).
Moderate startin
g
torque, hi
g
h brea
k
do
wn
torque, hi
g
h startin
g
cur
r
ent. Used on eas
y
-startin
g
e
quipment, such as belt driven
f
ans and blow
ers
,
g
rinders, centri
f
u
g
al pumps,
g
ear motors, etc.
S
p
lit
p
hase start-ca
p
acitor run
.
P
e
r
fo
r
ma
n
ce
a
n
d
applications similar to split phase start-induction run,
H
[FHSWKDYHKL
J
KHUH
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FLHQF
\

Capacitor start-induction run
(
or simpl
y
capacitor
start or capacitor
).
Hi
g
h startin
g
and brea
k
do
wn
torque, medium startin
g
cur
r
ent. Used on hard startin
g
applications; com
pres
sors
,
pos
i
tive displacement pumps,
f
arm equi
p
ment, etc.
Capacitor start-capacitor run
(
two-value
).
Per
f
ormance and applications similar to ca
pac
i
t
o
r
s
t
a
rt-
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J
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*H
Q
HU
D
OO
\
used in hi
g
her sin
g
le phase HP ratin
g
s.

T
hree Phase
.
O
perate on three phase power onl
y
.
+
L
J
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J
DQGEUHD
N
GRZQWRUTXHKL
J
KH
I
¿
F
L
HQ
F\

me
di
um startin
g
current, no startin
g
switch or auxiliar
y
windin
g
, simple, ru
gg
ed d
e
s
i
g
n, lon
g
li
f
e. For all t
y
pes
of
i
n
dus
tr
i
a
l
uses
.
M
otor Terminolo
gy
Guid
e