Schneider Electric 58 TRX manual Protection, 227

Class 8998 Motor Control Centers

Sample Specifications

2.09 Protection

a.The AC drive controller unit shall be protected against fault currents up to and including 100,000 A rms symmetrical at 480 Vac and shall be UL 845 listed as verification.

b.Upon power-on, the AC inverter shall automatically test for a valid operation of memory, option module, loss of analog reference input, loss of communication, dynamic brake failure, DC to DC power supply, control power, and the pre-charge circuit.

c.The AC drive controller unit shall be protected against short circuits between output phases, between output phases and ground, on the internal power supplies, and on the logic and analog outputs.

d.The AC drive controller unit shall have a minimum AC undervoltage power loss ride-through of 200 milliseconds (12 cycles). The AC inverter shall have the user-defined option of frequency fold-back to increase the duration of the power-loss ride-through.

e.The AC inverter will have a selectable ride through function which will allow the logic to maintain control for a minimum of one second (60 cycles) without faulting.

f.For a fault condition (other than ground fault, short circuit, or internal fault), an auto restart function shall provide up to six restart attempts. The time delay before restart attempts shall be 30 seconds.

g.The deceleration mode of the AC inverter shall be programmable. The stop modes shall include freewheel stop, fast stop, and DC injection braking.

h.Upon loss of the analog process follower reference signal, the AC inverter shall be programmable to fault or operate at the user-defined low speed setting.

i.The AC inverter shall have solid-state I2t protection that is UL Listed, meets UL 508C as a Class 10 overload protection, and meets IEC 60947. The minimum adjustment range shall be from 0.45% to 1.05% of the nominal current rating of the AC drive controller unit.

j.The AC inverter shall have a programmable skip frequency with a bandwidth of 2.5 Hz.

k.The AC inverter shall have a programmable fold-back function that will anticipate drive overload condition and fold back the frequency to avoid a fault condition.

l.The output frequency shall be software enabled to foldback when the motor is overloaded.

2.10 Adjustments and Configurations

a.The AC inverter motor and control parameters will be factory preset to operate most common applications. Necessary adjustments for factory-supplied unit operator controls and sequencing shall be pre-programmed and tested by the manufacturer.

b.A choice of two types of acceleration and deceleration ramps will be available in the AC inverter software, linear or S-curve.

c.The acceleration and deceleration ramp times shall be adjustable from 0.05 to 999.9 seconds.

d.The volts/frequency ratios shall be user selectable to meet variable torque loads for normal and high- torque machine applications.

e.The memory shall retain and record the last fault for operator review.

f.The software shall have an Energy Economy (no load) function that will reduce the voltage to the motor when selected for variable torque loads. A constant volts/hertz ratio will be maintained during acceleration. The output voltage will then automatically adjust to meet the torque requirement of the load.

g.The AC inverter shall have an output signal with a user-selectable threshold that can be used to signal motor overtemperature before a motor overload fault.

h.The AC inverter shall offer programmable DC injection braking that will brake the AC motor by injecting DC current and creating a stationary magnetic pole in the stator.

09/2003

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