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
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
1=on
0=off
Shaft speed
Start delay time
on
off
Brake delay time
Time
Output current
Relay 01
Pre-magnetizing
current or
DC hold current
Reaction time EMK brake
Par 2-20
Release brake current
Par 1-76 Start current/
Par 2-00 DC hold current
Par 1-74
Start speed
Par 2-21
Activate brake
speed
Mechanical brake
locked
Mechanical brake
free
Par 1-71
Par 2-23
130BA074.12
Figure 3.33 Mechanical Brake Control in Open-loop
Product Introduction
Design Guide
56
Danfoss A/S © Rev. 2014-02-10 All rights reserved.
MG34S222
3
3
Summary of Contents for VLT AutomationDrive FC 300
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