Danfoss VLT Training Manual page 25

Hide thumbs Also See for VLT:

VLT Installation

4) Installation Checks

b. Environmental Concerns

Another variable that can derate the drive is elevation. The higher the location for

the drive, the thinner the air and the less cooling occurs. In the chart above, as the

altitude increases as shown on the bottom, the output of the drive is reduced.

Notice at 2km (6600 feet) the output of the VLT is approximately 93%.

Derating can also occur when the switching frequency is increased, larger than rated

cable sizes are used and when running the motors continually at slow speeds.

Contact the Danfoss Drives if there are questions about the mounting location and

environment of the drive and its ability to provide long term, reliable operation.

Rev.02

b. Environmental Concerns

Derating for Higher Elevation

Derating for High Switching Frequency

Derating for Larger than rated Cable Area

Derating for Running at Low Speeds

Confidential / Property of Danfoss Drives A/S

North America

Motion Controls

Table of Contents