Danfoss VLT Pocket Guide

44 VLT
®
Soft Starter Pocket Guide
There are three diff erent types of soft starter which off er diff erent
features and control the motor in diff erent ways.
Torque controllers control only one phase during start. This reduces 1.
the torque shock at start but does not reduce start current. Torque
controllers must be used in conjunction with a direct on-line starter.
Soft starters which control two phases can reduce start current as 2.
well as eliminating torque transients, and are suitable for normal
and heavy duty loads, but not severe loads. The start current on the
uncontrolled phase is slightly higher than the two controlled phases.
Soft starters which control all three phases provide the maximum 3.
level of soft start control and are the only soft start solution that is
suitable for severe duty applications.
Types of Soft Starter: What are the diff erent types
of soft starters?

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)