OPERATING MANUAL for
BRAKE UNITS
JB10/... JB16/... JB26/... JB40/... JB52/...
(Installation set)
JB
11 of 19
01.96/00/Scho
•
Release contactor K2 (or K3). K1 will pick up again. After the braking
time (approximately 20 seconds) has elapsed, LED "B" will go out
and braking contactor K1 will drop out.
•
This ends the interlocking test.
•
Switch off the mains voltage.
9.3
SETTING THE BRAKING CURRENT I
Br
It must be ensured that the braking and motor contactors cannot be
active at the same time (see 9.2, Interlocking Test).
A clamp-ammeter with t.r.m.s. response capability is required to set the
braking current. Connect this meter to the line which is connected to
terminal X2.b of the braking unit.
With JB26/..., JB40/..., and JB52/... units the adjustment can be a-
chieved by means of the bar display (see below).
•
The mains voltage must be switched off.
•
Insert the motor fuses or switch on the motor protective switch(es).
•
Set trimming potentiometer "T" to its ¼ (9 o'clock) position by turning
it anti-clockwise.
•
Set trimming potentiometer "I" to its minimum (fully anti-clockwise).
•
Switch on the mains power.
A dangerously high voltage will now be present at the JB
brake unit.
•
Start the motor and let it warm up. LEDs "P" and "M" must light.
•
Switch off the motor. LED "M" will go out. LED "B" will light. The
braking contactor will pick up. Braking has commenced.
•
Increase the braking current from zero until the motor is distinctly
braked, by turning trimming potentiometer "I" slowly in a clockwise
direction. Ensure that the maximum braking current of the brake unit
is not exceeded by observing the readings on the ammeter.
(With JB26/..., JB40/..., JB52/... units:
The braking current can be read off the bar display on the control
board. 1 bar = 10% of the maximum braking current I
Br
).
Note: A good braking effect can usually be obtained at the ½ (12
o'clock) position of trimming potentiometer "I".
•
LED "S" (standstill monitoring) will light while the braking current is
flowing and the motor is still turning. LED "S" will go out at
approximately 10% of the nominal speed. The braking process ends
as soon as LED "S" goes out and any subsequent braking time set
with trimming potentiometer "T" (up to 20 seconds) has elapsed. LED
"B" will go out and the braking contactor will drop out.
Adjustment of the braking current is now completed.
10 MAINTENANCE
The JB brake unit is largely maintenance free.
However, under very dusty conditions, regular cleaning is essential.
!
