10.3 Fuse
Tables
It is recommended to use fuses and/ or Circuit Breakers on
the supply side as protection in case of component break-
down inside the frequency converter (first fault).
NOTE
This is mandatory in order to ensure compliance with IEC
60364 for CE or NEC 2009 for UL.
WARNING
Personnel and property must be protected against the
consequence of component break-down internally in the
frequency converter.
Branch Circuit Protection
In order to protect the installation against electrical and fire
hazard, all branch circuits in an installation, switch gear,
machines etc., must be protected against short-circuit and
over-current according to national/international regulations.
NOTE
The recommendations given do not cover Branch circuit
protection for UL!
Short-circuit protection:
Danfoss recommends using the fuses/Circuit Breakers
mentioned below to protect service personnel and property
in case of component break-down in the frequency
converter.
Over current protection:
The frequency converter provides overload protection to
limit threats to human life, property damage and to avoid
fire hazard due to overheating of the cables in the instal-
lation. The frequency converter is equipped with an internal
over current protection (
4-18 Current Limit
) that can be used
for upstream overload protection (UL-applications excluded).
Moreover, fuses or Circuit Breakers can be used to provide
the over current protection in the installation. Over current
protection must always be carried out according to national
regulations.
10.3.1 Recommendations
WARNING
In case of malfunction, not following the recommendation
may result in personnel risk and damage to the frequency
converter and other equipment.
The following tables list the recommended rated current.
Recommended fuses are of the type gG for small to medium
power sizes. For larger powers, aR fuses are recommended.
For Circuit Breakers, Moeller types have been tested to have
a recommendation. Other types of circuit breakers may be
used provide they limit the energy into the frequency
converter to a level equal to or lower than the Moeller types.
If fuses/Circuit Breakers according to recommendations are
chosen, possible damages on the frequency converter will
mainly be limited to damages inside the unit.
For further information please see Application Note
Fuses
and Circuit Breakers
, MN.90.TX.YY
Specifications
VLT
®
AutomationDrive Operating
Instructions
76
MG.33.AJ.02 - VLT
®
is a registered Danfoss trademark
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