10.3 Fuse Tables
10.3.1 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 converter. 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.
10.3.2 Fuse Selection
Danfoss recommends 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.
The fuses below are suitable for use on a circuit capable of
delivering 100,000 Arms (symmetrical).
N110-N315
380–500 V
type aR
N75K–N400
525–690 V
type aR
Table 10.5
Power
Size
Fuse options
Bussman
PN
Littelfuse PN Littelfuse
PN
Bussmann
PN
Siba PN
Ferraz-Shawmut
PN
Ferraz-Shawmut PN
(Europe)
Ferraz-Shawmut PN
(North America)
N110
170M2619 LA50QS300-4 L50S-300
FWH-300A 20 610
31.315
A50QS300-4
6,9URD31D08A0315
A070URD31KI0315
N132
170M2620 LA50QS350-4 L50S-350
FWH-350A 20 610
31.350
A50QS350-4
6,9URD31D08A0350
A070URD31KI0350
N160
170M2621 LA50QS400-4 L50S-400
FWH-400A 20 610
31.400
A50QS400-4
6,9URD31D08A0400
A070URD31KI0400
N200
170M4015 LA50QS500-4 L50S-500
FWH-500A 20 610
31.550
A50QS500-4
6,9URD31D08A0550
A070URD31KI0550
N250
170M4016 LA50QS600-4 L50S-600
FWH-600A 20 610
31.630
A50QS600-4
6,9URD31D08A0630
A070URD31KI0630
N315
170M4017 LA50QS800-4 L50S-800
FWH-800A 20 610
31.800
A50QS800-4
6,9URD32D08A0800
A070URD31KI0800
Table 10.6 Fuse Options for 380-480 V Frequency Converters
OEM
Fuse options
VLT Model
Bussmann PN
Siba PN
Ferraz-Shawmut European PN
Ferraz-Shawmut North American PN
N75k T7
170M2616
20 610 31.160
6,9URD30D08A0160
A070URD30KI0160
N90k T7
170M2619
20 610 31.315
6,9URD31D08A0315
A070URD31KI0315
N110 T7
170M2619
20 610 31.315
6,9URD31D08A0315
A070URD31KI0315
N132 T7
170M2619
20 610 31.315
6,9URD31D08A0315
A070URD31KI0315
N160 T7
170M2619
20 610 31.315
6,9URD31D08A0315
A070URD31KI0315
N200 T7
170M4015
20 620 31.550
6,9URD32D08A0550
A070URD32KI0550
N250 T7
170M4015
20 620 31.550
6,9URD32D08A0550
A070URD32KI0550
N315 T7
170M4015
20 620 31.550
6,9URD32D08A0550
A070URD32KI0550
N400 T7
170M4015
20 620 31.550
6,9URD32D08A0550
A070URD32KI0550
Table 10.7 Fuse Options for 525-690 V Frequency Converters
Specifications
VLT
®
AQUA Drive D-Frame
Operating Instructions
78
MG21A202 - VLT
®
is a registered Danfoss trademark
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