Short Circuit Current Rating (Sccr); Connection Tightening Torques - Danfoss VLT FC 100 Operating Instructions Manual

Specifications
For UL compliance, for units supplied without a contactor-
only option, the Bussmann 170M series fuses must be
used. See Table 10.9 for SCCR ratings and UL fuse criteria if
a contactor-only option is supplied with the frequency
converter.

10.3.3 Short Circuit Current Rating (SCCR)

If the frequency converter is not supplied with a mains
disconnect, contactor or circuit breaker, the Short Circuit
Current Rating (SCCR) of the frequency converters is
100,000 amps at all voltages (380–690 V).
If the frequency converter is supplied with a mains
disconnect, the SCCR of the frequency converter is 100,000
amps at all voltages (380–690 V).
If the frequency converter is supplied with a circuit
breaker, the SCCR depends on the voltage, see Table 10.8:
415 V 480 V
D6h frame 100,000 A 100,000 A
D8h frame 100,000 A 100,000 A
Table 10.8
If the frequency converter is supplied with a contactor-only
option and is externally fused according to Table 10.9, the
SCCR of the frequency converter is as follows:
415 V 480 V
1)
IEC UL
D6h frame 100,000 A 100,000 A
D8h frame (not 100,000 A 100,000 A
including the
N315T4)
D8h frame 100,000 A Consult
(N315T4 only) factory
Table 10.9
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.
®
VLT HVAC Drive D-Frame
Operating Instructions
600 V 690 V
65,000 A 70,000 A
42,000 A 30,000 A
600 V 690 V
2) 2) 1)
UL IEC
100,000 A 100,000 A
100,000 A 100,000 A
Not applicable
®
MG16D202 - VLT is a registered Danfoss trademark

10.3.4 Connection Tightening Torques

When tightening all electrical connections it is very
important to tighten with the correct torque. Too low or
too high torque results in a bad electrical connection. Use
a torque wrench to ensure correct torque. Always use a
torque wrench to tighten the bolts.
Frame Size Terminal
D1h/D3h/D5h/ Mains
D6h Motor
Load sharing
Regen
Earth (Ground)
Brake
D2h/D4h/D7h/ Mains
D8h Motor
Regen
Load sharing
Earth (ground)
Brake
Table 10.10 Torque for Terminals
Torque Bolt size
19-40 Nm
(168-354 in- M10
lbs)
8.5-20.5 Nm
M8
(75-181 in-lbs)
19-40 Nm
(168-354 in- M10
lbs)
8.5-20.5 Nm
M8
(75-181 in-lbs)
79
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