Illustration 5.17: Mounting of bottom plate,frame size E1.
The bottom plate of the E1 can be mounted from either in- or outside of the enclosure, allowing flexibility in the installation process, i.e. if mounted from
the bottom the glands and cables can be mounted before the frequency converter is placed on the pedestal.
5.2.8 Fuses
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-circuit
and over-current protected according to the 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 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. Over current protection must always
be carried out according to national regulations. 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
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.
Over-current protection
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 frequency converter.
5 How to Install
VLT
®
HVAC Drive Design Guide
96
MG.11.B9.02 - VLT
®
is a registered Danfoss trademark
5
