Overcurrent protection
Provide overload protection to avoid fire hazard due to overheating of the cables in the installation. Overcurrent protection must always
be provided in accordance with national regulations. The adjustable frequency drive is equipped with internal overcurrent protection
that can be used for upstream overload protection (UL applications excluded). See par. 4-18
Current Limit
in the VLT HVAC Drive
Programming Guide
. Fuses must be designed for protection in a circuit capable of supplying a maximum of 100,000 A
rms
(symmetrical),
500 V/600 V maximum.
If UL/cUL is not to be complied with, Danfoss recommends using the fuses mentioned in the table below, which will ensure compliance with EN50178.
In case of malfunction, not following the recommendation may result in unnecessary damage to the adjustable frequency drive.
UL compliance
Non-UL compliance fuses
Adjustable frequency
drive
Max. fuse size
Voltage
Type
200–240 V - T2
1K1-1K5
16A
1
200–240 V
type gG
2K2
25A
1
200–240 V
type gG
3K0
25A
1
200–240 V
type gG
3K7
35A
1
200–240 V
type gG
5K5
50A
1
200–240 V
type gG
7K5
63A
1
200–240 V
type gG
11K
63A
1
200–240 V
type gG
15K
80A
1
200–240 V
type gG
18K5
125A
1
200–240 V
type gG
22K
125A
1
200–240 V
type gG
30K
160A
1
200–240 V
type gG
37K
200A
1
200–240 V
type aR
45K
250A
1
200–240 V
type aR
380–480 V - T4
1K1-1K5
10A
1
380–500 V
type gG
2K2-3K0
16A
1
380–500 V
type gG
4K0-5K5
25A
1
380–500 V
type gG
7K5
35A
1
380–500 V
type gG
11K–15K
63A
1
380–500 V
type gG
18K
63A
1
380–500 V
type gG
22K
63A
1
380–500 V
type gG
30K
80A
1
380–500 V
type gG
37K
100A
1
380–500 V
type gG
45K
125A
1
380–500 V
type gG
55K
160A
1
380–500 V
type gG
75K
250A
1
380–500 V
type aR
90K
250A
1
380–500 V
type aR
1) Max. fuses - see national/international regulations to select an appropriate fuse size.
Table 4.3:
Non-UL fuses 200 V to 480 V
VLT
®
HVAC Drive Instruction Manual
4 Electrical Installation
MG.11.AB.22 - VLT
®
is a registered Danfoss trademark
4-5
4