Danfoss VLT HVAC Design Guide

5.2.12 Electrical Installation, Control Cables
Illustration 5.20: Diagram showing all electrical terminals. (Terminal 37 present for units with Safe Stop Function only.)
Very long control cables and analog signals may in rare cases and depending on installation result in 50/60 Hz earth loops due to noise from mains supply
cables.
If this occurs, you may have to break the screen or insert a 100 nF capacitor between screen and chassis.
The digital and analog in- and outputs must be connected separately to the frequency converter common inputs (terminal 20, 55, 39) to avoid ground
currents from both groups to affect other groups. For example, switching on the digital input may disturb the analog input signal.
NB!
Control cables must be screened/armoured.
VLT
®
HVAC Drive Design Guide 5 How to Install
MG.11.B9.02 - VLT
®
is a registered Danfoss trademark 103
5

Danfoss VLT HVAC Specifications

General

Enclosure Rating	IP20, IP21, IP54, IP55, IP66
Storage Temperature Range	-25°C to +70°C
Output Voltage Range	0-100% of supply voltage
Communication Protocols	Modbus RTU, BACnet, Ethernet/IP, Profibus DP
Ambient Temperature Range	-10°C to +50°C (without derating)
Relative Humidity	5% to 95% non-condensing
Altitude	Up to 1000 m without derating
Cooling Method	Air cooled
Application	HVAC systems, Pumps, Fans, Compressors
Voltage Range	200-240 V, 380-500 V, 525-600 V
Frequency Range	0 Hz to 590 Hz