Danfoss VLT Pocket Guide

36 VLT
®
Soft Starter Pocket Guide
Type 2 protection requires that in the event of a short circuit on the
output of a soft starter the fault must be cleared without risk of injury
to personnel or damage to the soft starter.
Type 2 protection is provided by semiconductor fuses, which must be
able to carry motor start current and have a total clearing I2t less than
the I
2
t of the soft starter SCRs.
Semiconductor fuses for Type 2 circuit protection are additional to HRC
fuses or MCCBs that form part of the motor branch circuit protection.
Refer to the soft starter’s Design Guide for semiconductor fuse
recommendations.
Short Circuit Protection: What is required for Type 2
short circuit protection of a soft starter?

Danfoss VLT Specifications

General

Frequency	50/60 Hz
Enclosure	IP20, IP21, IP55, IP66
Series	VLT
Control Technique	Flux Vector Control
Output Voltage	0-Vinput
Control Method	Fieldbus
Communication Interface	PROFIBUS, CANopen
Protection Features	Overload, Overvoltage, Undervoltage, Short Circuit, Ground Fault
Cooling Method	Liquid Cooled
Storage Temperature	-25°C to +70°C
Relative Humidity	5-95% non-condensing
Altitude	Up to 1000m (3280ft) without derating, up to 4000m (13120ft) with derating
Operating Temperature	-10°C to +50°C (14°F to 122°F)