5.2.8 Fuses
A Adjustable frequency drive that works correctly limits the
current it can draw from the supply. Still, it is
recommended to use fuses and/ or circuit breakers on the
supply side as protection in case of component break-
down inside the Adjustable frequency drive (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
consequences of component breakdown internally in the
Adjustable frequency drive.
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 overcurrent 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 listed
in and to protect service personnel and property in case of
component break-down in the Adjustable frequency drive.
Overcurrent protection:
The Adjustable frequency drive provides overload
protection to limit threats to human life, property damage
and to avoid fire hazard due to overheating of the cables
in the installation. The Adjustable frequency drive is
equipped with an internal overcurrent 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 overcurrent
protection in the installation. Overcurrent protection must
always be provided in accordance with national
regulations.
How to Install
VLT
®
HVAC Drive Design Guide
MG11BB22 - VLT
®
is a registered Danfoss trademark
5-15
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