Siemens 7MH7300 Series, Руководство по эксплуатации

Страница: 19 / 36

4. From the access side of the weighfeeder at the discharge end, grab the edge of the belt and
gently pull it over the side rail, making sure that the leading edge of the belt does not catch
on any components.
5. Repeat the previous step on the inlet end of the weighfeeder. Again, be careful not to cut or
scrape the belt on any components.
6. When both ends have been pulled to the outside of the side rail, grab the belt in the middle
and slowly remove it. As you are removing the belt, mark the direction the belt was rotating,
as this will allow you to re-install it in the same direction. Take care when storing the belt to
prevent kinks or other damage.
7. With the belt removed, inspect the weighfeeder for material buildup, lodged particles, and
signs of wear, paying close attention to the weighing section. Take care when cleaning the
weighing section, as 6 kg (15 lbs) (or less) pressure placed on the weighbridge could cause
load cell damage.
8. Reverse steps to re-install the same belt.
Note
● On a new replacement belt, there may be an arrow printed on the underside of the belt. This
arrow indicates what direction the belt should rotate when it is installed. If there is no arrow,
rotation of the belt may be in either direction. Whenever a new belt is installed, perform the
belt tracking procedure (see Belt tracking (Page 19)).
● New belts should be un-rolled and allowed to relieve any kinks or bends: this will help
tracking and weighing accuracy.
7.4 Belt tension
The ideal belt tension for any weighfeeder is just enough tension to prevent the belt from
slipping on the drive pulley. The tension minimizes the effect of the belt on weighing accuracy.
Often, the sole cause of an inaccurate weighfeeder is excessive belt tension.
Specific belt tension cannot be given because the weighfeeder could be mounted in various
applications. As a general guideline, the bottom of the belt should droop 1-2 inches (25-51 mm)
over the length of the weighfeeder. This is only an approximate specification, as your
application may require more or less tension due to varying belt loading and other operating
characteristics.
7.5 Belt tracking
Before attempting to track the belt, be sure:
• belt scraper is in place
• belt tension is near guidelines suggested in Belt tension (Page 19).
• weighfeeder is level and true
• installation has not warped or twisted the frame
Commissioning
7.5 Belt tracking
SITRANS WW200
Operating Instructions, 06/2018, A5E33560654-AC
19