7.2 Connection Tightening Torques
When tightening electrical connections, it is important to tighten with the correct torque. Using too little or too much
torque results in a bad electrical connection. Always use a torque wrench to ensure that the bolts are correctly torqued.
Mains
Motor
Regen
Load sharing
Ground
Brake
Bolt size
M10
M10
M10
M10
M8
M8
Torque [Nm (in-
lbs)]
19–40 (168–354)
19–40 (168–354)
19–40 (168–354)
19–40 (168–354)
8.5–20.5 (75–
181)
8.5–20.5 (75–181)
Table 7.15 Tightening of Terminals
7.3 Fuses and Circuit Breakers
Use recommended AC fuses or circuit breakers (or both) as protection against component breakdown inside the drive
system (first fault). DC fuses are provided with the VLT
®
Parallel Drive Modules basic kit.
NOTICE
The use of fuses on the supply side is mandatory for IEC 60364 (CE) compliant installations.
The use of recommended fuses and circuit breakers ensures that possible damage to the drive system is limited to damage
inside the unit. With the proper fusing, the drive system's short circuit current rating (SCCR) is 100000 A
rms
(symmetrical).
7.3.1 Protection
WARNING
Overheated cables are a fire hazard. Failure to use overload protection when installing cables can result in equipment
damage.
Branch circuit protection
To protect the installation against electrical and fire hazards, all branch circuits in an installation, switch gear, and machines
must be protected against short circuits and overcurrent according to national or international regulations.
Short-circuit protection
Avoid electrical or fire hazards by protecting the drive system against short circuits. To protect service personnel and
equipment against an internal failure in the unit, Danfoss recommends using the fuses described in
. The drive system provides full short-circuit protection against a short circuit on the motor output.
Overcurrent protection
To avoid fire hazards due to overheating of cables in the installation, use overload protection. The drive system is equipped
with an internal overcurrent protection that can be used for upstream overload protection. See
parameter 4-18 Current Limit
.
Moreover, fuses or circuit breakers can be used to provide the overcurrent protection in the installation. Overcurrent
protection must always be carried out according to national regulations.
7.3.2 Fuse Selection
Recommended AC fuses are listed in
chapter 7.3.2.1 Recommended Fuses for CE Compliance
and
.
NOTICE
Danfoss recommends using the appropriate AC fuses to ensure CE and UL compliance. If a malfunction occurs, not
following these recommendations can result in unnecessary damage to the drive system.
Specifications
VLT
®
Parallel Drive Modules
68
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MG37L202
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