Operation; Load Sensing; Speed Sensing; Differential Speed Detection - Siemens Milltronics BW500 Operating Lnstructions

Operation

Load Sensing

For the BW500 and BW500/L to calculate rate and totalize material flow along the belt
conveyor, a load signal representative of weight of material on the belt is required. The
load signal is provided by the belt scale. The BW500 and BW500/L is compatible with belt
scales fitted with 1, 2, 4, or 6
sensors, an optional LVDT conditioning card is required.
Specifications
Refer to
and connection.

Speed Sensing

For the BW500 and BW500/L to calculate rate and totalize material flow along the belt
conveyor, a speed signal representative of belt speed is required. For optimum accuracy
of the weighing system, and both constant and variable speed applications, a speed
sensor is required. The design speed (P014) and speed constant (P015) need to be
programmed.
In constant speed applications (no speed sensor), the BW500 can be programmed to
provide an internal speed signal. This is achieved by entering the design speed (P014) and
providing a contact closure across speed input terminals (17/18). The speed constant
(P015) defaults to 'jumpered' . This contact should change to open when the conveyor is
idle to prevent errant totalization.
In applications with two speed sensors, the BW500 can be programmed to provide
differential speed. % slip can be calculated, using the difference between the two speed
signals with reference to the first speed.
Specifications
Refer to
requirements and connection.

Differential Speed Detection

Dual point speed sensing is used for monitoring speed at two points in the system where
a difference in speed can be detrimental to the equipment or its operation. The two speed
sensors are typically applied on belt conveyors to give an alarm if excessive slip between
the head pulley and tail pulley is detected. The secondary speed sensor is especially
useful on variable speed conveyors, and may also be used to detect a malfunction in the
primary speed sensor.
The BW500 provides a 12 V DC, 150 mA maximum, regulated power supply for both
speed sensors. The primary speed sensor is used for all "Run" display integration, and is
the reference value for differential speed detection. The primary speed sensor is
generally reserved for the driven device (tail pulley). The second speed sensor is
1)
Not available with BW500/L
2)
Differential speed detection is not available on the BW500/L
7ML19985DK05Milltronics BW500 and BW500/L - OPERATING INSTRUCTIONS
1)
strain gauge type load cells. To function with LVDT type
Installation
on page 5, and
2)
Installation
on page 5 and
on page 9 for belt scale requirements
on page 9 for speed sensor
2)
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