Rockwell 70-602, Technical Manual

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24 VOLT LVC LOW VOLTAGE CONTROL
MAGNETIC MOTOR CONTROL SYSTEMS
I N T R O D U C T I O N - 2 4 V O L T L V C ( L O W V O L T A G E
C O N T R O L ) M A G N E T I C M O T O R C O N T R O L S Y S -
T E M S
T h e s i n g l e a n d t h r e e p h a s e d e f i n i t e p u r p o s e L o w
Voltage Control (LVC) motor starters have been de-
signed exclusively for use on stationary power tools.
The basic function of a definite purpose starter is to
provide ON-OFF motor control. In addition to pro-
viding ON-OFF control, every motor starter offers the
following features:
M O T O R O V E R L O A D P R O T E C T I O N - A l l s t a r t e r s
are supplied with thermal overload relays which pro-
tect the power tool motor from burnouts due to ex-
cessive heat resulting from a sustained motor over-
load, extended motor cycling, or stalled rotor.
N O V O L T A G E O R L O W V O L T A G E P R O T E C T I O N
( L V P ) - N o v o l t a g e o r l o w v o l t a g e p r o t e c t i o n p r e -
vents the dangerous restarting of a power tool follow-
ing a temporary power failure. Upon a loss of voltage
or a reduction of voltage, the magnetic contactor in
the starter will open. When power is restored, the
m o t o r w i l l n o t a u t o m a t i c a l l y r e s t a r t , b u t m u s t b e
manually restarted by pushing the start button of the
ON-OFF switch.
L O W V O L T A G E C O N T R O L ( L V C ) - T h e d e f i n i t e
purpose motor starters provide low voltage control
as a unique safety feature. The pushbutton ON-OFF
switch operates at a 24 volt level, not at line voltage.
The 24 volt low voltage control eliminates the possi-
bility of electrical shock to the operator.
S A F E T Y R U L E S
1. Installing and servicing should always
plished by qualified electrical personnel.
be accom-
2 . R e a d t h e i n s t r u c t i o n m a n u a l b e f o r e w i r i n g a n d
o p e r a t i n g t h i s m o t o r s t a r t e r . F a i l u r e t o f o l l o w i n -
structions can cause injury.
3. A l w a y s d i s c o n n e c t t h e e l e c t r i c a l p o w e r b e f o r e
removing the cover of the starter.
4. Operate the motor starter only with the cover of
the starter in place.
5. D o n o t o p e r a t e t h e m a c h i n e u n l e s s t h e m o t o r
starter is properly grounded as specified in the in-
structions.
6. Follow national and local electrical codes when
wiring the motor starter.
7. Always use proper heater coils as specified in the
heater coil chart located on the inside of the starter
cover.
8. Make sure the motor starter is disconnected from
the electrical power source before the primary con-
n e c t i o n s o f t h e c o n t r o l t r a n s f o r m e r a r e c h a n g e d .
9. Occasionally inspect the starter to ensure that it
is securely mounted, clean and dry.
This section includes a description of the basic LVC
motor starters, instructions for wiring the starters to
the power source, and instructions for changing the
voltage of a LVC motor starter.
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