OPERATING MANUAL for
BRAKE UNITS
JB10/... JB16/... JB26/... JB40/... JB52/...
(Installation set)
JB
9 of 19
01.96/00/Scho
8.3 ADJUSTMENT
ELEMENTS
IMPORTANT NOTE:
Unauthorised resetting of the adjustment elements can
cause malfunctions in the brake unit.
Trimming potentiometers:
Two trimming potentiometers are mounted on the control board.
Operation of the trimming potentiometers:
I :
Setting the brake current I
Br
Extreme anti-clockwise setting: minimum brake current
Extreme clockwise setting: maximum brake current
T : Setting the subsequent braking time
Extreme anti-clockwise setting: no subsequent braking time
Extreme clockwise setting: approximately 20 seconds
subsequent braking time
8.4
MOTOR CONTROL SYSTEM AND BRAKE UNIT
The JB brake unit must be used in conjunction with an existing or newly
built motor control system. Suitable connection diagrams for machines
with one or two motors may be found in the appendix.
The brake unit requires only a two-phase mains connection and must be
fused, as stated in the appendix. The cables to terminals X2.8/a/b must
have dimensions appropriate to the brake unit fuse.
The requisite braking contactor must have the same capacity as the
motor contactor. During switching the braking contactor on and off no
current passes through the main contacts.
In the case of machines with two or more drives, each
motor must be connected to the mains through its own
motor contactor. Failure to observe this requirement will
result in short-circuiting of the brake unit.
Do not open the brake contactor during braking! Do not
operate the brake contactor by hand! Failure to observe
this requirement can destroy the brake contactor and the
brake unit.
Terminal X1.n1 is the measurement input for detecting standstill. The
cable must be protected from the auxiliary switch of the brake contactor
as shown in the connection diagram.
Local requirements for earthing and cables must be observed.
8.5
OVERHEATING PROTECTION
(Only JB26/... JB40/... JB52/...)
These units have additional overheating protection. Should the heat sink
become too hot due to over-frequent braking, LED "O" will flash.
Switching on the motor will then be prevented, as contact n2/n4 will
remain broken. LED "O" will go out when sufficient cooling has taken
place. The motor can then be restarted.
9 COMMISSIONING
9.1
CHECKS BEFORE SWITCHING ON THE MAINS VOLTAGE
The JB brake unit is supplied unadjusted ex works, i.e. the trimming
potentiometers T (time) and I (current) are set to their minimum (fully
anti-clockwise). The unit must first be set to the relevant vibrating plant,
as described below.
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