Emerson Control Techniques Epsilon Eb-202, Справочное руководство

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Epsilon Eb and E Series EN Drives Reference Manual
Motor Direction Polarity
The direction that the motor turns with a positive command can be changed with the Positive
Direction parameter. This can be accessed with PowerTools in the EZ Setup tab or Detailed
Setup tab. The positive direction by default causes the motor to turn CW as viewed looking
at the shaft.
Note
CW and CCW rotation is determined by viewing the motor from the shaft end.
Figure 29: Clockwise Motor Rotation
Positive direction is defined as the command which causes the internal position counter to
count "Up". They are:
• A positive analog velocity or torque command (i.e., a higher voltage on the (+)
differential input than on the (-) input).
• A positive direction (+) pulse command.
• A positive preset velocity or torque command.
Current Foldback
Current foldback is used to protect the motor and drive from overload. There are two levels
of current foldback: RMS Foldback and Stall Foldback.
RMS and Stall Foldback are displayed on the diagnostic display as a "C" and "c" respectively.
RMS Foldback
RMS foldback protects the motor from overheating. The RMS Foldback parameter models
the thermal heating and cooling of the drive and motor based on the commanded current and
the motor velocity. On power-up, the RMS Foldback level is zero and is continually updated.
When the RMS Foldback level reaches 100 percent, current foldback is activated and the
Foldback Active output function is active.
Each drive is designed to deliver up to 300 percent of the motor’s continuous torque for no
less the two seconds when running at 100 RPM or more. If only 150 percent of continuous
torque is required, several seconds of operation before RMS foldback is typical.
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