FAIL-SAFE OPERATION
IMPORTANT: NOTE THE FOLLOWING.
1. This equipment is designed to meet the OSHA requirements for being fail-safe,
which are stated in Section 1910.217(b)(8)(vi) as follows:
"Electrical clutch/brake control circuits shall incorporate features to minimize the
possibility of unintended stroke in the event of the failure of a control component
to function properly, including relays, limits switches, and static output circuits."
The Model DM3000 BRAKE MONITOR design includes a self-checking circuit,
which operates continuously and independently of machine cycle, and detects
certain functional failures. Any failure detected by the self-check will cause the
control relay to de-energize and the SELF CHECK light to go on. The cause of the
malfunction must be determined before operation can continue.
2. Before installing the BRAKE MONITOR system, READ THE MANUAL.
Particularly note: Chapter 2 system information.
Chapter 3 for installation.
Chapter 4 for operation.
The system should be checked daily, in accordance with the operational test in
Chapter 4, or after any changes involving dies, personnel, or environment.
3. If constant readjustment is required, without changing conditions, something is
wrong with the system, environment, or installation, and must be corrected.
4. Obviously, fail-safe design is a matter of degree, i.e., reducing the probability of
unsafe failure to minimum practical level. The foregoing instructions are directed
at further reducing this probability level. The user must pay strict attention to all
factors regarding safety on a hazardous machine. This includes operator methods
and attitudes, use of complementary guarding, use of reliable fail-safe type
controls, and attention to situations peculiar to his particular operation.
5. A chain break detection circuit is provided to the monitor the output of a cam chain
driven Motion Detector. If, for any reason, (broken chain, etc.) the motion signal is
not present at the Brake Monitor after initiation of a stroke, the STOP ALARM relay
contact will open and prevent further cycling of the machine.
6. Additional assurance of safe operation may be realized by a periodic inspection of
the BRAKE MONITOR to see that stopping times are being indicated on the
display in a normal manner. Set the stop time below the normal stopping time of
the press and see that it prevents a subsequent cycle before resetting.
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