3.5.14. Fuses
Branch circuit protection:
In order to protect the installation against electrical and fire hazard, all branch circuits in an in-
stallation, switch gear, machines etc., must be short-circuited and over-current protected accord-
ing 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 equip-
ment in case of an internal failure in the drive. 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 par. 4-18. Moreover, fuses or circuit
breakers can be used to provide the over-current protection in the installation. Over-current pro-
tection must always be carried out according to national regulations.
Fuses must be designed for protection in a circuit capable of supplying a maximum of 100,000
A
rms
(symmetrical).
Fuse Tables
Size/
Type
Buss-
mann
E1958
JFHR2*
*
Buss-
mann
E4273
T/
JDDZ**
SIBA
E180276
RKI/JDDZ
LittelFuse
E71611
JFHR2**
Ferraz-
Shawmut
E60314
JFHR2**
Buss-
mann
E4274
H/
JDDZ**
Bussmann
E125085
JFHR2*
Internal
Option
Bussmann
P90K
FWH-
300
JJS-
300
2028220-
315
L50S-300
A50-P300
NOS-
300
170M3017
170M3018
P110
FWH-
350
JJS-
350
2028220-
315
L50S-350
A50-P350
NOS-
350
170M3018
170M3018
P132
FWH-
400
JJS-
400
206xx32-
400
L50S-400
A50-P400
NOS-
400
170M4012
170M4016
P160
FWH-
500
JJS-
500
206xx32-
500
L50S-500
A50-P500
NOS-
500
170M4014
170M4016
P200
FWH-
600
JJS-
600
206xx32-
600
L50S-600
A50-P600
NOS-
600
170M4016
170M4016
Table 3.5: D enclosures, 380-500 V
*170M fuses from Bussmann shown use the -/80 visual indicator, -TN/80 Type T, -/110 or TN/
110 Type T indicator fuses of the same size and amperage may be substituted for external use
**Any minimum 500 V UL listed fuse with associated current rating may be used to meet UL
requirements.
Size/Type
Bussmann
E125085
JFHR2
Amps
SIBA
E180276
JFHR2
Ferraz-Shawmut
E76491
JFHR2
P110
170M3017
315
2061032.315
6.6URD30D08A0315
P132
170M3018
350
2061032.35
6.6URD30D08A0350
P160
170M4011
350
2061032.35
6.6URD30D08A0350
P200
170M4012
400
2061032.4
6.6URD30D08A0400
P250
170M4014
500
2061032.5
6.6URD30D08A0500
P315
170M5011
550
2062032.55
6.6URD32D08A550
Table 3.6: D enclosures, 525-690 V
VLT
®
Automation Drive FC 300
Operating Instructions High Power
3. How to Install
MG.33.U1.02 - VLT
®
is a registered Danfoss trademark
57
3