9.7 Connection Tightening Torques
Make sure to use the right torques when tightening all electrical connections. Too low or too high torque may cause
electrical connection problems. Use a torque wrench to ensure that correct torques are applied.
Torque [Nm]
Enclosure
type
Power [kW] (hp)
Line power
Motor
DC connection
Brake
Ground
Control/Relay
K1
0.37–2.2 (0.5–3)
0.8
0.8
0.8
0.8
3
0.5
K2
3.0–5.5 (4–7.5)
0.8
0.8
0.8
0.8
3
0.5
K3
7.5 (10)
0.8
0.8
0.8
0.8
3
0.5
K4
11–15 (15–20)
1.2
1.2
1.2
1.2
1.6
0.5
K5
18.5–22 (25–30)
1.2
1.2
1.2
1.2
1.6
0.5
Table 9.3 Tightening Torques
9.8 Fuses and Circuit Breakers
Use fuses and/or circuit breakers on the supply side to protect service personnel and equipment from injuries and damage
in case of component breakdown inside the adjustable frequency drive (first fault).
Branch circuit protection
All branch circuits in an installation (including switch gear and machines) must be protected against short circuit and
overcurrent according to national/international regulations.
NOTICE!
The recommendations do not cover branch circuit protection for UL.
lists the recommended fuses and circuit breakers that have been tested.
WARNING
PERSONAL INJURY AND EQUIPMENT DAMAGE RISK
Malfunction or failing to follow the recommendations may result in personal risk and damage to the adjustable
frequency drive and other equipment.
•
Select fuses according to recommendations. Possible damage can be limited to be inside the adjustable
frequency drive.
NOTICE!
Using fuses and/or circuit breakers is mandatory to ensure compliance with IEC 60364 for CE.
Danfoss recommends using the fuses and circuit breakers in
on a circuit capable of delivering 5000 A
rms
(symmetrical) 380–480 V depending on the adjustable frequency drive voltage rating. With the proper fuses and/or circuit
breakers, the adjustable frequency drive short circuit current rating (SCCR) is 5000 A
rms
.
Specifications
VLT
®
Midi Drive FC 280
54
Danfoss A/S © 11/2015 All rights reserved.
MG07A122
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