11.3 Fuse Specifications
11.3.1 Protection
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 short-circuited and over-
current protected according to national/international
regulations.
Short-circuit Protection:
The frequency converter must be protected against short-
circuit to avoid electrical or fire hazard. Danfoss
recommends using the fuses mentioned below to protect
service personnel and equipment in case of an internal
failure in the frequency conveter. The frequency converter
provides full short-circuit protection in case of a short-
circuit on the motor output.
Over-current Protection:
Provide overload protection to avoid fire hazard due to
overheating of the cables in the installation. The frequency
converter is equipped with an internal over-current
protection that can be used for upstream overload
protection (UL-applications excluded). See
4-18 Current
Limit
. 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.
11.3.2 Non UL Compliance
If UL/cUL is not to be complied with, we recommend using
the following fuses, which will ensure compliance with
EN50178. In case of malfunction, not following the
recommendation may result in unnecessary damage to the
frequency converter.
N110 - N250
380 - 500 V
type gG
N315
380 - 500 V
type gR
Table 11.3
Specifications
VLT® Refrigeration Drive 110-250 kW Operating Instructions
MG16F102 - VLT® is a registered Danfoss trademark
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