D-Frame Short Circuit Current Rating (Sccr); Recommendations - Danfoss VLT AutomationDrive FC 300 Design Manual

Electrical Installation

7.2.2 D-frame Short Circuit Current Rating (SCCR)

If the adjustable frequency drive is not supplied with a line power disconnect, contactor, or circuit breaker, the Short Circuit
Current Rating (SCCR) of the adjustable frequency drives is 100,000 A at all voltages (380–690 V).
If the adjustable frequency drive is supplied with a line power disconnect, the SCCR of the adjustable frequency drive is
100,000 amps at all voltages (380–690 V).
If the adjustable frequency drive is supplied with a circuit breaker, the SCCR depends on the voltage. See Table 7.27.
415 V
D6h frame 120,000 A
D8h frame 100,000 A
Table 7.27 Adjustable Frequency Drive Supplied
with a Circuit Breaker
If the adjustable frequency drive is supplied with a contactor-only option and is externally fused according to Table 7.28, the
SCCR of the adjustable frequency drive is as follows:
D6h frame
D8h frame (not including the N250T5)
D8h frame (N250T5 only)
Table 7.28 Adjustable Frequency Drive Supplied with a Contactor
1)
With a Bussmann type LPJ-SP or Gould Shawmut type AJT fuse. 450 A max fuse size for D6h and 900 A max fuse size for D8h.
2)
Must use Class J or L branch fuses for UL approval. 450 A max fuse size for D6h and 600 A max fuse size for D8h.

7.2.3 Recommendations

WARNING
In case of malfunction, failure to follow these recommendations may result in personnel risk and damage to the
adjustable frequency drive and other equipment.
Danfoss recommends the fuses from the following tables. Selecting the proper fuses and circuit breakers minimizes damage
due to an overcurrent condition within the adjustable frequency drive. If fuses/circuit breakers are chosen according to
recommendations, possible damages are limited mainly to inside the unit.
For further information, see Application Note for FC 100, FC 200 and FC 300 Fuses and Circuit Breakers.
MG34S222
Design Guide
480 V
100,000 A
100,000 A
415 V 480 V
IEC 1) UL
100,000 A 100,000 A
100,000 A 100,000 A
100,000 A Consult factory
Danfoss A/S © Rev. 2014-02-10 All rights reserved.
600 V 690 V
65,000 A 70,000 A
42,000 A 30,000 A
600 V
2) UL 2)
100,000 A
100,000 A
Not applicable
7 7
690 V
IEC 1)
100,000 A
100,000 A
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