Danfoss VLT AutomationDrive FC 302 - Page 166

Motor cable length, m (ft)
dv/dt (kV/µs)
0
100
(328)
200
(656)
0.50
1.00
1.50
2.00
2.50
3.00
3.50
300
(984)
e30bu006.10
1
2
3
4
1 Shielded cable with no lter
2 Unshielded cable with no lter
3 Unshielded cable with dU/dt lter
4 Shielded cable with dU/dt lter
Illustration 10.19 Peak Voltages at Motor Terminals for
Enclosures E2h/E4h, 380–500 V
Motor cable length, m (ft)
Vpp/Vline
0
100
(328)
200
(656)
0.50
1.00
1.50
2.00
2.50
3.00
300
(984)
e30bu007.10
1
2
3
4
1 Unshielded cable with dU/dt lter
2 Shielded cable with dU/dt lter
3 Shielded cable with no lter
4 Unshielded cable with no lter
Illustration 10.20 Peak Voltages at Motor Terminals for
Enclosures E2h/E4h, 380–500 V
Test results for 525–690 V
NEMA does not provide dU/dt results for 690 V.
Power size [kW (hp)] Cable [m (ft)] Mains voltage [V]
Rise time [µs]
Peak voltage [V]
dU/dt [V/µs]
355–560 (400–600) 30 (98) 690 0.37 1625 3494
50 (164) 690 0.86 2030 1895
630–710 (650–750) 5 (16) 690 0.25 1212 3850
20 (65) 690 0.33 1525 3712
50 (164) 690 0.82 2040 1996
Table 10.35 IEC dU/dt Test Results for E1h–E4h with Unshielded Cables and No Output Filter, 525–690 V
Power size [kW (hp)] Cable [m (ft)] Mains voltage [V]
Rise time [µs]
Peak voltage [V]
dU/dt [V/µs]
355–560 (400–600) 5 (16) 690 0.23 1450 5217
48 (157) 690 0.38 1637 3400
150 (492) 690 0.94 1762 1502
630–710 (650–750) 5 (16) 690 0.26 1262 3894
48 (157) 690 0.46 1625 2826
150 (492) 690 0.94 1710 1455
Table 10.36 IEC dU/dt Test Results for E1h–E4h with Shielded Cables and No Output Filter, 525–690 V
Illustration 10.21–Illustration 10.24 show the typical rate of rise voltage and peak voltages at the motor terminals for both
shielded and unshielded cables in various congurations.
These values are true to steady state operation and at RMS input voltage range of the drive V
line
. When the drive operates in
braking mode, the intermediate DC-link voltage increases by 20%. This eect is similar to increasing the mains voltage by
20%. Consider this voltage increase when performing motor insulation analysis for braking applications.
Electrical Installation Con... VLT® AutomationDrive FC 302
164 Danfoss A/S © 01/2018 All rights reserved. MG38C202
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