e.
Variable torque volts per Hertz curve.
f.
Starting voltage level.
g.
Starting frequency level.
h.
Display speed scaling.
i.
Enable/disable auto-restart feature.
j.
Enable/disable soft stall feature.
k.
Motor overload level.
l.
Motor stall level.
m.
Jump frequency and hysteresis band.
n.
PWM carrier frequency.
2.8.7
Protective Circuits and Features
a.
An electronic adjustable inverse time current limit with
consideration for additional heating of the motor at frequencies
below 45Hz, for the protection of the motor.
b.
An electronic adjustable soft stall feature, allowing the
VFD to
lower the frequency to a point were the motor will run at
FLA when
an overload condition exists at the requested frequency.
The VFD
will automatically return to the requested frequency when
load
condition permit.
c.
The VFD will have a separate electronic stall at 110% VFD rated
current and a separate hardware trip at 190% current.
d.
The VFD shall have ground fault protection that protects output
cables and motor from grounds during both starting and continuous
running conditions.
e.
The VFD shall have the ability to restart after the following
faults:
(1)
Overcurrent (drive or motor).
(2)
Power outage.
(3)
Phase loss.
(4)
Overvoltage/Undervoltage.
e.
The VFD shall restart into a rotating load without tripping or
damaging the VFD or the motor.
f.
The VFD shall keep a log of a minimum of four previous fault
conditions, indicating type and time of occurrence in descriptive
text.
g.
The VFD shall be able to sustain 110% rated current for 60 sec.
SECTION 15910N
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