NSK M-EGA-15A2301, User Manual

Page: 38 / 237

2.Specifications Dynamic brake
2-10
2.6 Specifications for dynamic brake
1) Allowable frequency, instantaneous tolerance, decreasing the rotation angle of the dynamic
brake
■
Allowable frequency of the dynamic brake (main circuit power ON/OFF)
Limit the positioning operation to a range within 360 [°] within the allowable load moment of inertia.
■
Operation intervals
In basic terms, operation of the dynamic brake in six (6) minute intervals is acceptable. If the brake is to
be operated more frequently, the motor speed must be reduced sufficiently.
Refer to the following expression to find a standard of operation:
■
If/When load inertia moment (J
L
) substantially exceeds allowable load inertia moment or if/when
rotation through an angle exceeding 360 [°] is made, abnormal heat can generate due to
dynamic brake resistance. Take precautions against (Overheat alarm of the dynamic break) or
(failure of dynamic brake resistance). Please consult us if such a situation is evident.
■
Instantaneous tolerance of dynamic brake
E
RD
[J]
360
The consumption of energy E
RD
by dynamic brake resistance in one dynamic brake operation is as
follows:
J
M
：
Moment of inertia of motor rotor [kg
・
m
2
]
J
L
：
Load inertia moment [kg
･
m
2
]
N
：
Rotational speed [s
-1
]
E
RD
=
1
2
×
(J
M
+J
L
) ×
(2
π
N)
2
6[min]
(Rated rotation speed/maximum rotation speed in use)
2