Danfoss VLT HVAC Drive Instruction Manual page 23

In this lab, you will set up a VLT HVAC drive to simulate an air handler application. The drive will be
set up in an Open Loop configuration. In an open loop configuration, a speed reference signal fed
into the drive determines the speed it will run at. The drive will receive the control signals by
means of a Building Management System (BMS). The BMS will provide the VFD with an enable
command, a start/stop command and a 0‐10 Vdc speed reference. The drive itself will have two
relay outputs programmed to indicate when it is running, and another to indicate an alarm
situation. For this lab, you will use the control box provided to you to simulate the BMS I/O signals.

Identify the drive's power connections and control card terminals

Program the necessary drive parameters for basic open loop control

Use the drive's data readouts to verify that the control signals are working correctly

Upload a working set of parameters to the LCP
VLT HVAC Drive Lab # 2
Open Loop Speed Control
Introduction
Behavioral Objectives
22