Technical Data 12-3MN448
12.7 Motor Overload Summary
The EC Titanium Drive features both hardware and software protection of the output stage to prevent damage. In addition,
an I x t system is used to monitor motor overload condition and prevent damage to the motor due to operation for prolonged
periods at high load. I x t protection is software based, using the value for motor rated current programmed in 9906. An
internal accumulator register is used to estimate the point at which damage may occur to the motor, and operates as
follows:
Motor Current < 9908 The accumulator value reduces towards zero. The time
required depends on the actual load current as explained
further below.
Motor Current = 100% P-08
Motor Current > 100% P-08 < 150% P-08 The accumulator value increases at a rate proportional to
the overload level, e.g. (Motor Current / Rated current) –
100%. If the overload limit is reached, the drive will trip,
displaying it.trp. to protect the motor.
Motor Current > 150% P-08 For high current levels, the accumulator operates 16 times
faster than for current levels below 150% of 9906.
Peak over current trip levels are shown in the table below.
Drive Rated
Supply Voltage
Frame
Size Drive Type
DC Bus Voltage Level (Volts DC)
Brake
Chopper
On
Brake
Chopper
Off
Under
Voltage
Trip
Minimum
Operating
(Inrush
Disabled)
Over
Voltage
Trip
100 – 115 VAC 1 Voltage Doubler N/A N/A 160 239 418
110 – 240 VAC 1 PFC N/A N/A 160 239 418
200 – 240 VAC 1 All N/A N/A 160 239 418
380 – 480 VAC 1 All N/A N/A 320 478 835
380 – 480 VAC 2 All 780 756 320 478 835
12.8 Automatic Switching Frequency Reduction
The switching frequency selected in 2606 will be automatically reduced based on the heatsink temperature. In addition,
switching frequency is reduced under the following conditions:
Output Frequency based Effective Switching Frequency Reduction
At low output frequency, Effective Switching Frequency is automatically reduced. Hysteresis is applied to prevent continuous
switching. The operation is according to the following table:
2606 32kHz 24kHz 16kHz 12kHz 8kHz 4kHz
Effective Switching Frequency increases
when Output Frequency exceeds
9.0Hz 7.0Hz 5.0Hz 3.0Hz N/A N/A
Effective Switching Frequency reduces
when Output Frequency reduces below
7.0Hz 5.0Hz 3.0Hz 1.0Hz N/A N/A
Output Current Based Effective Switching Frequency Reduction
Effective Switching Frequency is automatically reduced based on motor load current as follows:
If 2606 = 12kHz, 16 kHz, 24 kHz, Effective switching frequency is reduced to 8 kHz when motor current exceeds 10.45A
(110% of the drive rated current). Switching frequency will return to the value set in 2606 when motor current reduces below
7.6A (80% of drive rated current)
If 2606 = 32kHz, Effective switching frequency is reduced to 8 kHz when motor current exceeds 10.45A (110% of drive
rated current). Switching frequency changes to 24 kHz when motor current reduces below 7.6A (80% of drive rated current).
Switching frequency will return to the value set in 2606 when motor current reduces below 6.7A (70% of drive rated current)
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