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3-22 BasicInstallation MN1942

3.5.6 Motor brake connection
Youmight wish to wire a motor’s brake, v ia relays, to digital outputs on connector X3 (see section
3.3.1). This prov ides a way for the Micr oFlex e100 to control the motor’s brak e. A typical circuit
iss hown in Figure 10.
C
D
frommotor brake
connections
Separate
customer
supplied
24VDCsupply
Relay2
Relay1
+24VDC 0V
Theinner shield
surroundingthe
brakewires should
beearthed/grounded
atone point only.
Therelays have normally open
contactsand are shown deactivated
(contactsopen, brake engaged).
DOUT0+
DOUT0-
11
1
DOUT1+
DOUT1-
13
3
Usersupply V+
Usersupply GND
‘X3’
Figure10 - Motor brake control circuit
Thisc ircuit uses the drive enable s ignal (configured using DRIVEENABLEOUTPUT to appear on
DOUT0)in conjunction w ith DOUT1 (configured as the MOTORBRAKEOUTPUT). See the Minthelp
filefor details. With t his configuration, the following sequences can be used to c ontrol the brake.
Toengage the brake:
HThemotor is brought to rest under normal control;
HRelay2 is deactivated, causing the brake to engage;
HThe drive is disabled. This removes power from the motor and caus es Relay 1 to be
deactivated.
Todisengage the brake:
HThedrive is enabled, activating Relay 1;
HPoweris applied to the motor to hold position under normal control;
HRelay2 is activated, causing the brake to be disengaged.
Itmay be necessary to include a small delay, after Relay 2 has been activated, before starting
motion.This delay will allow time for the relay contacts to engage and the brak e to release.
CAUTION: The 24VDC power supply used to power the brake must be a s eparate
supply as shown in Figure 10. Do not use the supply that is powering the
MicroFlexe100 digit al outputs. The brake wires often carry noise that could
causeerratic driveoperation or damage. The brak e contacts must nev er be
wired directly to the digital outputs. The relay(s) should be fitted with a
protectiveflyback diode, asshown. The separate 24VDC supplyused for the
motorbrake may also be used t o power the relay in the thermal switchcircuit
(section 3.5.5).