Danfoss VLT Pocket Guide

VLT
®
Soft Starter Pocket Guide 3
Soft Starter Selection Guide
Warnings ............................................................................................................................................. 5
Common Applications ................................................................................................................... 6
MCD Soft Starter Features and Specifi cations ...................................................................... 8
Current Ratings ............................................................................................................................... 10
Soft Starter Sizing .......................................................................................................................... 12
FAQs
AC53 Utilisation Codes ................................................................................................................ 13
Auto-Transformer Starters ......................................................................................................... 14
Bypass Contactor ........................................................................................................................... 15
Cabling ............................................................................................................................................... 16
Extreme Conditions ...................................................................................................................... 18
Fault fi nding .......................................................................................................................................19
Flying Loads ..................................................................................................................................... 20
Harmonics ........................................................................................................................................ 21
Inside delta Connection ...............................................................................................................22
IP Ratings .......................................................................................................................................... 23
Nema Ratings .................................................................................................................................. 24
Key Benefi ts ..................................................................................................................................... 25
Line Contactor ................................................................................................................................ 26
Minimum Start Current ............................................................................................................... 27
Motor Thermal Capacity ............................................................................................................. 28
Multiple Motors .............................................................................................................................. 29
Power factor correction .............................................................................................................. 31
Primary Resistance Starters ....................................................................................................... 32
Reversing .......................................................................................................................................... 33
Sealed Enclosures .......................................................................................................................... 34
Short Circuit Protection, Type 1 ................................................................................................ 35
Short Circuit Protection, Type 2 .................................................................................................36
Semiconductor Fuse Selection, Type 2 .................................................................................. 37
Slip-Ring Motors ............................................................................................................................ 38
Soft Braking ..................................................................................................................................... 39
Star/Delta Starters ......................................................................................................................... 40
Thermal Model Protection ......................................................................................................... 42
Two Speed Motors ........................................................................................................................ 43
Types of Soft Starter ..................................................................................................................... 44
Contents

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)