DM3000 Brake Monitor
A stop time measuring device for your power presses
A device that meets every requirement of OSHA regulation 1910.217b(14) for mechanical power presses*
Features microprocessor-based electronics, 3-digit LED display for stop or reserve (time to alarm) times, auto-learn mode, continuous self-check circuitry, chain break monitor, and enhanced relay protection (includes welded contact detection).
Principles of Operation
The DM3000 Brake Monitor system components are: a control unit and a motion detector (standard with 10′ cable – other lengths available upon request).
The control unit interfaces electrically with the motion detector, by means of a motion detector cable. The motion detector is mechanically connected to the crankshaft of the press by chain, belt or direct drive and generates an electrical signal whenever there is shaft movement.
The brake solenoid voltage (which is removed to apply the brake on the press) is constantly monitored by the control unit. When the voltage is removed, a high precision digital counter is activated, which continues to count until the motion detector signal indicates all motion has ceased. The elapsed time is indicated on a 3-digit LED display on the face of the control unit.
The Brake Monitor opens the control relay in the Stop Output circuit, whenever the stop time of the press exceeds the preset limit – the Stop Output must be wired in a way that prevents a successive stroke of the press. The Stop Output also features a safety relay with its contacts wired in series with those of the control relay. This safety relay works in conjunction with an armature configuration in the control relay, which allows for the detection of a welded relay contact, and opens the Stop Output if a contact weld occurs. A separate, adjustable Warning Output provides a means to alert personnel to the fact that stop times are approaching the alarm point – this feature warns of brake wear and helps to eliminate unintended machine stops.
The combination of a key lock and keypad allows the authorized user to alter the alarm, warning and chain-break delay settings and to control whether the unit displays stop or reserve times. The key lock enables the keypad access. An access code prevents unauthorized keypad entry.
A self-check circuit monitors the control. It operates continuously and is independent of machine cycle. In the event of a self-check fault, the Stop Output opens and a fault code is displayed on the 3-digit LED. A chain-break detection circuit monitors the motion detector input and alarms the unit if the motion detector is either disconnected or fails to provide a signal.
Meets OSHA Standard 1910.217 (b) (14)
- Stop Time Range from 0.01 to 10 Seconds
- Failsafe Design
- Exempts User from Weekly Inspection Requirements of OSHA 1910.217e
- Built-In Chain Break Detector
- NEMA 12 Industrial Enclosure
- Easily Installed by Plant Electrician
- Auto-Learn Mode for Ease of Setup
- Key lock and Keypad controls with User Access Code
- Brake Solenoid and Motion Input Lines Filtered for Noise Immunity
- CUL Listed
Mount the unit to the press. Use the Shock mount kit provided with the unit and install it exactly as shown in the image below:
Connect terminals 1, 2 & 3 to Ground, L1 and Neutral, respectively, of a 120 VAC line. (Figure 2)
Connect terminals 4 & 5 across the press Brake/Clutch Valve. (Figure 2)
Connect terminals 6 & 7 (DM3000 Stop Output) in series with the press control E-Stop Circuit. (Figure 2)
Connect terminals 10, 11 & 12 to interface for Loss of Motion. This is only for some older Allen-Bradley press controls. (Figure 2)
Connect the Motion Detector directly to the press camshaft with a flex-coupling (not included) or in the cam/crankshaft drive chain loop with a sprocket (not included).
Apply power. Run the DM3000 in the Autolearn Mode – the unit will automatically calculate alarm settings for your press.
You are finished. The unit will now measure Stop Times and monitor the condition of the brake.
The control unit should be mounted in an area that is easily visible to the operator. Here you can see that the device is mounted directly on the back frame of some guarding components of the press.
The motion detector can be mounted anywhere along the drive chain. In this application is was tucked underneath the chain guard and mounted on the frame of the press.
Here is an example of a motion detector integrated into a cam box. This method can simplify mounting and reduce installation time. Call us to obtain manufacturers who will install our motion detector into their cam box.