Mechanical Brake Control - Danfoss VLT AutomationDrive FC 300 Design Manual

Product Introduction

3.9 Mechanical Brake Control

For hoisting applications, controlling an electro-magnetic brake is necessary. For controlling the brake, a relay output (relay1
or relay2) or a programmed digital output (terminal 27 or 29) is required. Normally, this output must be closed for as long
3 3
as the adjustable frequency drive is unable to 'hold' the motor. In 5-40 Function Relay (array parameter), 5-30 Terminal 27
Digital Output, or 5-31 Terminal 29 Digital Output, select [32] mechanical brake control for applications with an electro-
magnetic brake.
When [32] mechanical brake control is selected, the mechanical brake relay remains closed during start until the output
current is above the level selected in 2-20 Release Brake Current. During stop, the mechanical brake will close when the
speed is below the level selected in 2-21 Activate Brake Speed [RPM]. If the adjustable frequency drive is brought into an
alarm condition, such as an overvoltage situation, the mechanical brake immediately cuts in. This is also the case during
safe torque off.
Start
term.18
Par 1-71
Start delay time
Shaft speed
Output current
Pre-magnetizing
current or
DC hold current
Par 2-23
Brake delay time
Relay 01
Mechanical brake
locked
Mechanical brake
free
Figure 3.33 Mechanical Brake Control in Open-loop
56
1=on
0=o
Par 1-74
Start speed
Par 1-76 Start current/
Par 2-00 DC hold current
on
o
Danfoss A/S © Rev. 2014-02-10 All rights reserved.
Design Guide
Par 2-20
Release brake current
Reaction time EMK brake
Par 2-21
Activate brake
speed
Time
MG34S222