Fagor QC-PDS - 5.7 Ballast resistor selection guide

 Selection criteria
5.
SELECTING CRITERIA
Ballast resistor selection guide
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198
Ref.2003
QC-PDS
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5.7 Ballast resistor selection guide
Calculate the value of:
Based on the following formulae:
where:
Wm Energy generated by the braking of each system motor.
Pe Rms power generated by all braking of all the motors throughout
a complete duty cycle.
Jt Total inertia of the servo system (mass of the mobile elements of
the motor and mechanics) with regard to the rotation axis in kg·m².
n Turning speed of the motor when the braking starts (in rpm).
Wmi Energy of each braking during a cycle of time T in Ws.
Wp Potential energy lost by the machine mass while braking (only on
non-compensated axes) (in Ws).
ti Braking time (in seconds) when the Wmi energy is generated.
T Time (in seconds) in a full cycle.
Dh Height (in m) lost while braking .
Wmx Maximum energy among all the Wm.
Pmx Maximum power generated by the braking, given by the maximum
value among all the (Wmi/ti) quotients of each braking (in kW).
W
m
W
p
1
2
---+ J
t
2 n

60
--------------
2
 Ws=
W
p
mgh=
P
e
W
mi
2
t
i
-----------
i

T
--------------------
W=
P
mx
W
mi
t
i
------------



max
kW=