3.5.13. External Fan Supply
If the adjustable frequency drive is supplied by DC or if the fan must run independently of the
power supply, an external power supply can be applied. The connection is made to the power
card.
Terminal No.
Function
100, 101
102, 103
Auxiliary supply S, T
Internal supply S, T
The connector located on the power card provides the line voltage connection for the cooling fans.
The fans are factory-equipped to be supplied from a common AC line (jumpers between 100-102
and 101-103). If an external supply is needed, the jumpers are removed and the supply is con-
nected to terminals 100 and 101. A 5 Amp fuse should be used for protection. In UL applications,
this should be LittelFuse KLK-5 or equivalent.
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 overcurrent protected accord-
ing to national/international regulations.
Short-circuit protection:
The adjustable frequency drive must be protected against short circuit in order to prevent 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 drive. The adjustable frequency drive provides
full short-circuit protection in case of a short-circuit on the motor output.
Overcurrent protection
Provide overload protection to avoid fire hazard due to overheating of the cables in the installation.
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. Moreover, fuses or
circuit breakers can be used to provide the overcurrent protection in the installation. Overcurrent
protection 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).
3. How to Install
VLT
®
Automation Drive FC 300
Instruction Manual High Power
60
MG.33.U1.22 - VLT
®
is a registered Danfoss trademark.
3