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Service and maintenance 

 

7.2 Replacing a load cell 

 

Milltronics MUS 

36

 

Operating Instructions, 06/2012, 7ML19985CQ02-02 

7.2

 

Replacing a load cell 

 

CAUTION 

 

Re-install the shipping stops during maintenance or any other time when protection of the 

load cells is required. 

 

1.

 

Install both shipping stops 

2.

 

Support the belt and weighing idler from above or below. 

3.

 

Remove load cell hardware from the dynamic (moving) parts. 

4.

 

Remove load cell hardware from the static support. 

5.

 

Remove the existing load cell from the belt scale. 

6.

 

Replace with a new load cell fastening to static support then dynamic (moving structure). 

7.

 

Remove belt and idler support. 

8.

 

Release both shipping stops 

9.

 

Adjust idler alignment if necessary. 

10.

 

Perform balance, zero, and span calibrations. 

 

 

 

Note 

 

The load cell stop is set at the factory to allow the load cell to deflect up to 150% of its design 

load (30 mV at 10 V DC excitation). The overload gap for a replacement load cell should be set 

by mV readings. 

7.3

 

Spare parts 

The only spare part recommended for the belt scale is the load cell. Refer to the load cell 

nameplate for the proper size and model number. Re-balance any load cell that has been 

replaced. 

Содержание Milltronics MUS

Страница 1: ...Milltronics Belt Scales Milltronics MUS Belt Scale Operating Instructions 06 2012 ...

Страница 2: ...und version and in electronic version We encourage users to purchase authorized bound manuals or to view electronic versions as designed and authored by Siemens Milltronics Process Instruments Siemens Milltronics Process Instruments will not be responsible for the contents of partial or whole reproductions of either bound or electronic versions While we have verified the contents of this manual fo...

Страница 3: ..._______________ ___________________ ___________________ ___________________ Milltronics Belt Scales Milltronics MUS Operating Instructions 06 2012 7ML19985CQ02 02 Introduction 1 Safety notes 2 Description 3 Installing mounting 4 Connecting 5 Commissioning 6 Service and maintenance 7 Technical data 8 Dimension drawings 9 ...

Страница 4: ...levant documentation in particular its warning notices and safety instructions Qualified personnel are those who based on their training and experience are capable of identifying risks and avoiding potential hazards when working with these products systems Proper use of Siemens products Note the following WARNING Siemens products may only be used for the applications described in the catalog and i...

Страница 5: ...onveyor curvature 15 4 2 5 Belt ploughs 16 4 2 6 Stacker conveyors 16 4 2 7 Conveyor trippers 16 4 2 8 Skirt boards and sealing strips 17 4 3 Load cell handling 17 4 4 Installation precautions 18 4 5 Installation Procedure 19 4 5 1 Installation introduction 19 4 5 2 Remove the idler 19 4 5 3 Remove the idler foot plate and modify the idler frame at both ends 20 4 5 4 Idler mounting 20 4 5 5 Positi...

Страница 6: ...6 3 Balancing 32 6 4 Final calibration 32 6 5 Zero calibration 33 6 6 Span calibration 33 6 7 Material test 33 6 8 Re rating 33 7 Service and maintenance 35 7 1 Maintenance 35 7 2 Replacing a load cell 36 7 3 Spare parts 36 7 4 Technical support 37 8 Technical data 39 8 1 Specifications 39 9 Dimension drawings 43 9 1 Outline dimensions 43 ...

Страница 7: ...e is being applied 1 1 The manual This manual covers only belt scale installation operation and maintenance procedures Integrator and speed sensor operating instructions are available for download from our website Siemens weighing http www siemens com weighing Follow these operating instructions for quick trouble free installation and maximum accuracy and reliability of your weighing system We alw...

Страница 8: ...Introduction 1 1 The manual Milltronics MUS 6 Operating Instructions 06 2012 7ML19985CQ02 02 ...

Страница 9: ...equires proper transport storage positioning and assembly as well as careful operation and maintenance Only qualified personnel should install or operate this instrument Note Alterations to the product including opening or improper repairs of the product are not permitted If this requirement is not observed the CE mark and the manufacturer s warranty will expire ...

Страница 10: ...Safety notes 2 1 General safety instructions Milltronics MUS 8 Operating Instructions 06 2012 7ML19985CQ02 02 ...

Страница 11: ...terrupting the process and without affecting the process material 3 2 Principle of operation Belt scales work with an existing belt conveyor and the selected Siemens integrator As material moving along the conveyor belt travels over the belt scale it exerts a force proportional to the material load through the suspended idler to the load cells The belt scale reacts only to the vertical component o...

Страница 12: ...Description 3 2 Principle of operation Milltronics MUS 10 Operating Instructions 06 2012 7ML19985CQ02 02 ...

Страница 13: ...cable glands to maintain NEMA or IP rating as applicable Adjust conveyor stringers to be rigid straight parallel to and square with the belt line in the area of the scale installation Adjust pulleys to ensure that the conveyor belt tracks straight and centrally from the head to the tail pulley The idler to be used on the scale and at least the next two approach and retreat idlers must be of the sa...

Страница 14: ... in a given belt cause considerable change in the weight per unit length of the belt During the course of zero calibrations belt scales average the weight of the belt over one complete circuit of the belt Large deviations from the average adversely affect the zero calibrations 4 2 3 Head pulley Note Use caution when installing a scale in a short conveyor or when locating the scale near the head pu...

Страница 15: ...ors with 20 trough idlers throughout a minimum of two fixed 20 idlers must be located between the scale idler and the head pulley 20º idlers Minimum 3 idler spaces Head pulley Belt scale Note On conveyors with 35 trough idlers throughout a minimum of two 35 and one 20 retreat idlers must be located between the scale and the head pulley 35º idlers Minimum 4 idler spaces Head pulley 20º idler 35º id...

Страница 16: ...e Note The vertical displacement of the head pulley relative to the adjacent retreat idler is normally in excess of that which is acceptable for belt scale installations When locating the scale close to the head pulley a maximum of 13 mm vertical displacement between the top of the head pulley and the top of the center of the adjacent roll is allowed 13 mm 1 2 maximum Head pulley 20 idler center r...

Страница 17: ...rrectly The curvature whether concave internal or convex external disturbs the idler alignment if the scale is installed in the area of curvature The concave curve tends to lift the belt off of the idlers in the area of curvature as belt loading decreases adversely affecting the zero calibration Note Avoid locating the scale within the tangents of scale curvature Concave Minimum 12 m 40 ft Tangent...

Страница 18: ...of load Note Do not install the scale within 9 m 30 ft of belt ploughs or similar devices that contact the material or belt 4 2 6 Stacker conveyors Any conveyor that is not a permanent structure which varies in its incline elevation or profile is not considered a good installation for an accurate belt scale A belt scale can be used effectively in this conveyor type but requires special setup Sieme...

Страница 19: ...area If not adjust skirting so sealing strip does not put excess force on the belt or allow pinching of material 4 3 Load cell handling The MUS belt scale is designed for low to high capacity operation and is constructed using two load cells Although the load cells are protected by shipping stops that keep the cells from moving care should be taken when handling the scale to avoid damaging the cel...

Страница 20: ...f a hammer when trying to position the scale during installation Do not lift the scale by its idler Do not lift the scale by the idler mounting brackets Note For general safety and best system performance the belt scale must be grounded through the conveyor and the conveyor must be grounded to earth CAUTION Arc welding Use extreme caution when arc welding in the area of the belt scale Ensure that ...

Страница 21: ...5 1 Installation introduction The MUS installation has eight steps 1 Remove the idler s 2 Remove the idler foot plate 3 Idler mounting 4 Position the weigh module 5 Position the scale 6 Release the shipping stops 7 Align and level the idlers 8 Check alignment 4 5 2 Remove the idler Remove the idler s from the desired location on the conveyor ...

Страница 22: ...r vibration When this occurs gusset plate reinforcements should be welded to the idler at the joints of the horizontal spine and the outer vertical leg member 12 7 mm 0 5 Before After See notes below Note Cut idler support as shown to allow clearance when the load is applied 4 5 4 Idler mounting The belt scale is usually installed in conveyors employing conventional rigid structure idlers Within t...

Страница 23: ...s MUS Operating Instructions 06 2012 7ML19985CQ02 02 21 Troughed idler with channel spine Gusset reinforcement if required 12 7 mm 0 5 100 mm 4 Idler modification Optional flat bar weight mounting Idler clip Customer s idler Mounting bolts Idler installation ...

Страница 24: ...ics MUS 22 Operating Instructions 06 2012 7ML19985CQ02 02 Troughed idler with pipe spine Gusset reinforcement if required 12 7 mm 0 5 100 mm 4 Idler modification Optional flat bar weight mounting Idler clip Customer s idler Mounting bolts Idler installation ...

Страница 25: ...ics MUS Operating Instructions 06 2012 7ML19985CQ02 02 23 Troughed idler with angle spine Gusset reinforcement if required Idler clip 100 mm 4 Idler modification Optional flat bar weight mounting Idler clip Customer s idler Mounting bolts Idler installation ...

Страница 26: ...he scale idler is centered between the adjacent approach and retreat idlers Ensure that the scale is centered and square to the stringers and idler and clamping brackets have suitable clearance Dimension n approach idlers location of removed idler retreat idlers Note Be sure there is sufficient clearance between the return belt MUS and its test weight when used during the calibration procedure ...

Страница 27: ...e Mark the position and make new mounting holes suited for M12 1 2 bolts Refer to the Outline Dimensions Place the scale on the conveyor stringers with the arrows on the weigh modules pointing in the direction of belt travel retreat idlers Mount the modified idler onto the scale using the idler clamping brackets Idler clamping brackets ...

Страница 28: ... stops Release the shipping stops in order to free the weighing mechanism Loosen A screws and rotate both shipping stops downward until the shipping stop is 180 degrees from its starting position Tighten screws to secure in place A screws shipping stops Note Shipping bracket must be removed prior to aligning the idlers in the weighing area ...

Страница 29: ...within 0 8 mm 1 32 of each other Check that the idlers are centered and squared to the conveyor during the shimming process center of idlers to be in line A2 to R2 0 8 mm 1 32 reference Idlers must be square to stringers adjust idler last Note Precise idler alignment is very important to achieve maximum accuracy of the weighing system Misaligned idlers will result in unwanted forces being applied ...

Страница 30: ...r to eliminate any sag Adjust shims so that all rolls of the A2 through to the R2 idlers are in line within 0 8 mm 1 32 A2 A1 S1 R1 R2 MUS with modified idler wire or string for alignment Although the accepted tolerance for idler alignment is 0 8 mm 1 32 the scale mounted idler should never be lower than the adjacent idlers Establishing good idler alignment is the most important part of the instal...

Страница 31: ...onics MUS Operating Instructions 06 2012 7ML19985CQ02 02 29 Connecting 5 5 1 Belt scale wiring Load cells complete with 3 m 10 ft cable in flexible conduit with 1 2 NPT panel connector Load cell B Load cell A ...

Страница 32: ...grator SIWAREX FTC RED EXC EXC BLK EXC EXC WHT SIG A SIG GRN SIG A SIG A SHIELD SHIELD SHIELD RED EXC EXC BLK EXC EXC WHT SIG B SIG GRN SIG B SIG B SHIELD SHIELD SHIELD Note To avoid affecting the weighing process do not support conduit or load cell cables on the weighing idler or on the idler support components of the belt scale ...

Страница 33: ...to the integrator operating instructions for programming and calibration details and for information about material tests All operating instructions are available for download at our web site Siemens weighing http www siemens com weighing 6 2 Test load The test load value is required for calibration of the integrator Enter the calculated value into the associated programming parameter of the integ...

Страница 34: ... test weight to the extreme sides side A or B as required Test weight bracket Test weight calibration flat bar Note Position the test weight flush with the sides of the brackets when balancing load cells Reverse position of bar to balance other load cell 6 4 Final calibration Program the belt scale integrator as suggested in its operating instructions and with parameters suitable for the applicati...

Страница 35: ...libration test weight s to the scale 3 Perform the span calibration as described in the Calibration section of the integrator operating instructions After completing the span calibration remove the test weights and store them With a successful zero and span calibration and with the test weight s removed from the belt scale the belt scale system is ready for operation Ensure that the belt scale int...

Страница 36: ...Commissioning 6 8 Re rating Milltronics MUS 34 Operating Instructions 06 2012 7ML19985CQ02 02 ...

Страница 37: ... in the conveyor it is possible that the scale will be affected Therefore periodic conveyor maintenance is important to proper scale operation which should include lubrication of all pulleys and idlers proper belt tracking and training proper belt cleaning and scraping proper take up operation proper material feeding and spillage control You can observe the integrity of the load cells by performin...

Страница 38: ...ing load cell from the belt scale 6 Replace with a new load cell fastening to static support then dynamic moving structure 7 Remove belt and idler support 8 Release both shipping stops 9 Adjust idler alignment if necessary 10 Perform balance zero and span calibrations Note The load cell stop is set at the factory to allow the load cell to deflect up to 150 of its design load 30 mV at 10 V DC excit...

Страница 39: ...Service Support on the Internet In addition to our documentation we offer a comprehensive knowledge base online on the Internet at Service Support http www siemens com automation service support There you will find The latest product information FAQs downloads tips and tricks Our newsletter providing you with the latest information about your products Our bulletin board where users and specialists...

Страница 40: ...Service and maintenance 7 4 Technical support Milltronics MUS 38 Operating Instructions 06 2012 7ML19985CQ02 02 ...

Страница 41: ... test flow rate for three revolutions of the belt or at least ten minutes running time whichever is greater Load Cell Construction Nickel plated alloy steel Enclosure IP66 rated Excitation 10 V DC nominal 15 V DC maximum Output 2 mV V excitation at rated load cell capacity Non linearity 0 02 of rated output Hysteresis 0 02 of rated output Non repeatability 0 01 of rated output Capacity standard du...

Страница 42: ...8 1 Conveyor incline 20 from horizontal fixed incline up to 30 with reduced accuracy Review by Siemens application engineer required Conveyor idler flat to 35 up to 45 with reduced accuracy Review by Siemens application engineer required Idler diameter 50 to 180 mm 2 to 7 Idler spacing 0 6 to 1 5 m 2 0 to 5 0 ft Interconnection to integrator 150 m 500 ft 0 75 mm2 18 AWG 6 conductor shielded cable ...

Страница 43: ...Technical data 8 1 Specifications Milltronics MUS Operating Instructions 06 2012 7ML19985CQ02 02 41 Approvals Europe CE Australia C TICK EMC performance available upon request ...

Страница 44: ...Technical data 8 1 Specifications Milltronics MUS 42 Operating Instructions 06 2012 7ML19985CQ02 02 ...

Страница 45: ...s 10 kg 22 lbs per side 184 7 25 19 0 75 168 6 63 140 5 50 559 22 1 2 M12 mounting bolts customer supplied Calibration bar support test weight Shipping brackets Weigh idler MUS Belt Scale standard duty side view dimensions in mm inches Note 2 approach and 2 retreat idlers should be aligned with the weight idler to within 0 8 to 0 mm 1 32 to 0 Contact your Siemens representative with any questions ...

Страница 46: ... 06 2012 7ML19985CQ02 02 Standard Duty Front View 122 4 81 76 3 00 Shipping brackets Standard base CEMA idler or equivalent customer supplied Existing conveyor stringers Belt width 230 mm 9 based on CEMA sizes or to suit MUS Belt Scale standard duty front view dimensions in mm inches ...

Страница 47: ... weight 30 kg 64 lbs 15 kg 32 lbs per side 186 7 32 19 0 75 203 8 00 159 6 25 616 24 25 1 2 M12 mounting bolts customer supplied Calibration bar support test weight Shipping brackets weigh idler MUS Belt Scale heavy duty side view dimensions in mm inches Note 2 approach and 2 retreat idlers should be aligned with the weight idler to within 0 8 to 0 mm 1 32 to 0 Contact your Siemens representative ...

Страница 48: ...ons 06 2012 7ML19985CQ02 02 Heavy Duty Front View 143 5 62 76 3 00 Shipping brackets Standard base CEMA idler or equivalent customer supplied Existing conveyor stringers Belt width 230 mm 9 based on CEMA sizes or to suit MUS Belt Scale heavy duty front view dimensions in mm inches ...

Страница 49: ......

Страница 50: ...emens com level For more information www siemens com processautomation Siemens AG Industry Sector 1954 Technology Drive P O Box 4225 Peterborough ON Canada K9J 7B1 Subject to change without prior notice 7ML19985CQ02 Rev 2 3 email techpubs smpi siemens com Siemens AG 2012 7ml19985CQ02 ...

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