Yaskawa i80M Connecting Manual - Manual (Page 308)

A4. CHARACTERISTICS
A4. 1 OVERLOAD CHARACTERISTICS
The overload protective circuit built in YASNAC prevents the motor and Servopack from over-
load and restricts the allowable conduction time of Servopack.(See Fig. A4. 1.)
The overload detection level is determined precisely with the hot start conditions of
ambient temperature 55°C and cannot be changed.
NOTE
Hot start is the overload characteristics
when the Servopack is operating at the
rated load and thermally saturated.
MOTOR RATED CURRENT(%)
Fig. A4. 1 Overload Characteristics
A4. 2 STARTING AND STOPPING TIME
T h e s t a r t i n g t i m e a n d s t o p p i n g t i m e o f s e r v o m o t o r u n d e r a c o n s t a n t l o a d i s s h o w n
by the formula below. Viscous or friction torque of the motor is neglected.
Starting Time: 104. 7x
(L/~+
Stopping Time :
N R ( J
M
+
‘ i n s )
Where,
N
R
: Rated motor speed ( rpm)
Motor moment of inertia
J
L
( = Load moment of inertia
Torque constant of motor (N. m/A= lb in/A)
Motor rated current (A)
a
Acceleration/deceleration
constant
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