Northwest Dryer & Machinery Co.
|
|
|
|
PLUG UP DETECTOR SYSTEM
The NORTHWEST Plug-Up Detector System has been the standard of the industry for over thirty years. Over 350 systems have been installed and maintained. Each one, delivering the value through performance of increased dryer productivity and throughput. In November, 2002 we re-designed the internal circuitry of the control panel, replacing the obsolete timer relays with printed-circuit-board components that are more reliable, faster, and available. The entire system has been upgraded to state-of-the-art technology integrated onto the main circuit board, communicating with a secondary “Daughter Board” that contains the indicating lights and reset switch. The heart of the system is a micro controller that has more computing power than a 486 computer from the ‘90s. It’s programmed with the logic required to monitor the segment detector circuits continuously and activate the indicator LEDs and alarm sequence as needed. The Main Board and the Detection Module Boards are equipped with onboard capacitors that condition the control voltage to increase the sensitivity of the detection wires even after weeks of pitch buildup that minimize conductivity. As the system is powered up, the system does a self-test, the LEDs blink on in sequence until all segments indicate green. As material rolls through the dryer normally, the indicating LEDs show green. Momentary fluctuations caused by bark or knots, etc. will cause the system to show a Red LED at the corresponding segment. If the condition is transient, and lasts less than 4 seconds, the LED changes back to green and no further action occurs. If the condition lasts for 4 seconds, the alarm sequence is energized- the corresponding segment LED blinks yellow, and the external alarm circuit is energized. Typically the operator will push the reset button 2-3 times to make sure the condition still exists. The Detector will reset to monitor for an alarm condition. Should the alarm sequence exist after this procedure dryer personnel (or external PLCs) determine the next course of action. Inside the dryer, the detection system is divided into segments. Each segment consists of the required bracketry and insulators that suspend the detection wire just above the gudgeon stem of the upper roll. As a plug-up starts to occur the upper roll is lifted, and makes electrical contact with the detection wire. The Control Panel receives this signal and the timer sequence begins. At 4 seconds the alarm circuit is energized; the corresponding LED turns red and the 120 VAC alarm circuit is activated-connected to the customer-supplied alarm device. Periodic maintenance of the system will enhance the reliability of the detection sequences; inspection and replacement of worn springs, insulators, and wire are essential to keep the system in top running order. Each segment should be intentionally shorted to cause an alarm condition to make sure the circuitry is in proper operating condition. We carry a complete stock of spare parts for the detectors to keep your system up and running. A Plug-Up Detection System will pay for itself several times over in increased throughput and material saved.
REPLACEMENT PARTS:
|
|
|
