Emerson Epsilon Eb Series Reference Manual page 56

Example 1:
If the Motor Type is an MG-316, the maximum motor speed of the MG-316 is 4000 RPM. If
the Line Voltage parameter is set to 230 VAC and the Velocity Limit is equal to 112.5 percent
of 4000 RPM or 4500 RPM.
Example 2:
If the Motor Type is an MG-316, the maximum motor speed of the MG-316 is 4000 RPM. If
the Line Voltage parameter is set to 115 VAC, the Velocity Limiting Active output will never
come on.
Overspeed Velocity Parameter
Motor speed is continuously monitored against the Overspeed Velocity parameter whether
the drive is enabled or not and when the motor speed exceeds the limit, or Overspeed Velocity
Limit, a fault is issued. The default value for Overspeed Velocity Limit is 13000 RPM.
The drive has an internal overspeed velocity limit. This limit is the maximum of the
Overspeed Velocity parameter and 150% of the motor maximum operating speed. For
example, an MG-316 with 4000 RPM maximum speed the internal limit is 6000 RPM.
The Overspeed fault will be activated when either one of these two conditions are met:
1. When the actual motor speed exceeds the Overspeed Velocity Limit parameter.
2. If the combination of command pulse frequency and Pulse Ratio can generate a motor
command speed in excess of the fixed limit of 13000 RPM. In Pulse mode operation and
any Summation mode which uses Pulse mode, the input pulse command frequency is
monitored and this calculation is made. For example: with a Pulse Ratio of 10 pulses per
motor revolution, the first pulse received will cause an Overspeed fault even before there
is any motor motion.
In Motion Velocity
The In Motion Velocity parameter defaults to a value of 10 RPM. If the motor Velocity
Feedback is above the In Motion Velocity value, the In + Motion or In - Motion output
function is active. When the motor velocity falls below one half of the In Motion Velocity,
the In + Motion or In - Motion output function is inactive.
The maximum value for In Motion Velocity is 100 RPM and is intended to be used to indicate
"in motion" not "at speed".
Note
The In Motion Velocity detect is monitored every 400 µs so machine jitter and torque
ripple could cause flicker in this signal if the commanded velocity is near the In Motion
Velocity parameter value.
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Operational Overview
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