Operating Instruction

Transcription

1 Level and Pressure Operating Instruction VEGASWING 71 A

2 Contents Contents Safety information Product description 1.1 Function and configuration Functional principle Technical data Dimensions Mounting 2.1 Mounting instructions Electrical connection 3.1 Connection instructions Wiring plan Set-up 4.1 Switching condition Switch point Functional schedule Diagnosis 5.1 Function test Exchange of electronics Maintenance Safety information The described module must only be inserted and operated as described in this operating instruction. Please note that other action can cause damage for which VEGA does not take responsibility. 2 VEGASWING 71 A

3 Product description 1 Product description 1.1 Function and configuration VEGASWING 71 A vibrating level switch detects levels of liquids with a viscosity of 0, mpa s and a density of 0,6 g/cm 3. Due to the compact construction the vibrating level switch can be used in machines, plants, vessel and pipelines even in narrow spaces. Typical applications are overfill protections and protections against dry running of pumps. VEGASWING 71 A is available with threads G 1 A and NPT 1. The stainless steel housing (1.4571) is in protection IP 67. Due to the simple and rugged measuring system, VEGASWING can be virtually used in any liquid unaffected by the chemical and physical features. VEGASWING operates even under arduous conditions such as turbulences, air bubbles, foam generation, build-up or varying measured product. An adjustment to the product is not required. The electronics can be exchanged without problems. VEGASWING must not be dismounted. 1.2 Functional principle The tuning fork is piezoelectrically energized and vibrates on its mechanical resonance frequency of appr. 400 Hz. This frequency is transferred to the electronics of the tuning fork. When the tuning fork is covered, the frequency changes. This change is detected by the integral oscillator and converted into a switching command. Due to different connection of the consumer (load) a PNP or NPN-reaction can be reached. By appropriate connection of the supply voltage, the switching reaction can be defined (max. level detection/min. level detection). The integral fault monitoring detects: - Interruption of the connection line to the piezo elements. - Extreme build-up on the tuning fork. - Break of the tuning fork. - Failure of the vibration. If one of the above failures is determined or the supply voltage fails, the electronics takes a defined switching condition; the output transistor blocks. VEGASWING has an integral test switch which can be magnetically activated. This switch tests the sensor electronics and the connected instruments. VEGASWING 71 A 3

4 Product description 1.3 Technical data Housing Housing material stainless steel Protection IP 67 Connection - plug connection 4-pole plug with switch point indication (illuminated ring) - cable connection 4-wire cable (5 m long) Terminals max. 1 x 1,5 mm 2 Mechanical connection Thread G 1 A or NPT 1 Material (stst) Tuning fork Material Weight Total weight Ambient conditions Ambient temperature on the housing Storage and transport temperature Product temperature (stst) appr. 0,4 kg -40 C 70 C -40 C 70 C -40 C 150 C 70 C 50 C 30 C C Operating pressure max. 40 bar Product Viscosity 0, mpa s Density 0,6 g/cm 3 Electronics (transistor output E72 T) Supply voltage V DC Power consumption max. 0,5 W Output floating transistor output NPN/PNP selectable Load current max. 400 ma (output - overload resistant and permanently shortcircuit proof) Voltage loss max. 1 V Turn-on voltage max. 55 V DC Blocking current < 10 µa Protection class II Overvoltage category III 4 VEGASWING 71 A

5 Product description Function Mode Integration time Meas. frequency Hysteresis Signal lamp A - max. detection or overfill protection B - min. detection or protection against dry running of pumps A/B-mode by connection of supply voltage appr. 0,5 s appr. 400 Hz appr. 4 mm with vertical installation illuminated ring with LED for indication of switching condition (in conjunction with plug connection) CE-conformity VEGASWING 71 A vibrating level switch meets the protective regulations of EMVG (89/336/EWG) and NSR (73/23/EWG). The conformity has been judged acc. to the following standards: EMVG Emission EN : 1993 Susceptibility EN : 1995 NSR EN : Dimensions Cable connection 24 Plug connection 40 SW G 1 A or NPT 1" Switch point ø29 ø60 Welded socket VEGASWING 71 A 5

6 Mounting 2 Mounting 2.1 Mounting instructions Generally VEGASWING can be installed in any position. The instrument must be just mounted such that the tuning fork is at the height of the requested switch point. Observe the following instruction for installation: Switch point The tuning fork is provided with lateral marking (carves, 25 mm from the fork tip), marking the switch point with vertical installation relating to water. Note when mounting VEGASWING that the markings are at the height of the requested level. Note that the switch point shifts when the measured product has a density deviating from water (water = 1,0 g/cm 3 ). Transport Do not hold VEGASWING at the tuning fork. The tuning fork can be damaged. Adhesive products In case of adhesive and viscous products the tuning fork should protrude into the vessel, to avoid build-up on the mounting boss. A mounting boss should hence not exceed a length of 30 mm. appr. 30 mm Switch point with lower density Switch point Switch point with higher density appr Fig. 2.2 In case of horizontal mounting in adhesive and viscous products the surfaces of the tuning fork should be vertically beside each other to reduce build-up on the tuning fork to a minimum. The position of the tuning fork is shown by two markings on the hexagon of VEGASWING. Hence you can check the position of the tuning fork during mounting. One of the markings should point to the top. If the hexagon is on the seal, the thread can be turned approx. half a turn. This is sufficient to reach the recommended installation position. Switch point Marking on top Switch point Switch point Fig. 2.1 Fig VEGASWING 71 A

7 Mounting Cable entries When mounting outside, on cooled vessels or in humid areas in which e.g. cleaning is made with steam or high pressure, the sealing of the cable entries is very important. Use cable with a sufficient cross-section area of conductor and tighten the cable entry. In case of cables with small cross-section area of conductor, an appropriate reduction piece must be used so that the cable entry remains tight. The cable entry should possibly point downwards to avoid humidity ingress. Proceed as follows. Loosen the plug by unscrewing it with the knurled ring. Loosen the connection screw and remove the socket insert out of the angle housing of the plug. You can rotate the angle housing of the plug in 60 -steps (see fig. 3.1 under 3.1 Connection instructions ). With vertically mounted VEGASWING lead the connection line to the instrument housing to the bottom so that rain water and condensation can drain off Fig. 2.5 Welded socket VEGASWING has a defined thread begin. This means that VEGASWING is always in the same position after screwing in. Hence remove the supplied seal from the thread of VEGASWING. This seal is not required when using a welded socket. Screw VEGASWING into the welded socket. You can determine the final position of VEGASWING before the welding (see fig. 2.3). Mark the respective position of the welded socket. Before welding, unscrew the VEGASWING and remove the rubber ring from the welding socket. Flow (e.g. in pipelines) When mounting in pipelines or in vessels with a certain flow direction, VEGASWING should be mounted such that the tuning fork is along the flow direction. Fig. 2.4 VEGASWING 71 A 7

8 Electrical connection 3 Electrical connection 3.1 Connection instructions Note Switch off the power supply before you start connection. Pull the plug. Loosen connection screw (9) and dismount the plug. Lead the connection line through the cable entry and connect the lines acc. to the following figures. Cable connection 1 - Brown 2 - Green 3 - Yellow 4 - White Fig. 3.2 The numbers in above figure correspond to the numbering of the plug Plug connection Terminals 1-4 are marked on the plug. Connect potential separation on the earth terminal (6). Terminal Terminal Terminal Terminal 3 Fig. 3.3 Fig Socket insert 2 Angle housing 3 Seal ring (3 pieces for different cable-ø) 4 Terminal basket 5 Pressure screw 6 Earth terminal 7 Marking 8 Illuminated ring with LED 9 Connection screw 8 VEGASWING 71 A

9 Electrical connection 3.2 Wiring plan Floating transistor output (E72 T) Mode B Supply voltage: V DC (for further information see the following switching examples as well as the technical data). The supply lines (terminal 1 and 4) must be polarized appropriately to determine the switch condition of the transistor output (mode A/B). Mode A Max. level detection or overfill protection: - Terminal 1: - Terminal 4: Mode B Min. level detection or detection against dry running of pumps: - Terminal 1: - Terminal 4: NPN-reaction The transistor switches a second voltage source with the same reference potential to the binary input of a DCS or to an electrical load. Mode A PNP-reaction Due to the different connection of the consumer (load) NPN or PNP-reaction can be reached. Note when connecting, that terminal 2 must always have more positive voltage potential against terminal 3. Switching examples The transistor switches the supply voltage of the oscillator to the binary input of a DCS or to an electrical load. NPN-reaction Mode B PNP-reaction Mode A NPN-reaction PNP-reaction NPN-reaction PNP-reaction VEGASWING 71 A 9

10 Electrical connection The transistor switches a second, galvanically separated voltage source to the binary input of a DCS or to an electrical load. Mode A For mode B exchange the polarization of terminals 1 and 4. NPN-reaction PNP-reaction Control of the alternating current loads The transistor switches a galvanically separated alternating voltage V AC to a load. Mode A ~ ~ Note The transistor output of several VEGASWING 71 A can be switched in series or in parallel to connect their signal logically. The wiring must be carried out such that terminal 2 has always higher voltage against terminal VEGASWING 71 A

11 Set-up 4 Set-up 4.1 Switching condition The switching condition of the electronics can be checked with closed housing by means of the illuminated ring in the upper part of the housing (only with plug connection). By interchanging the connection lines you modify the switching condition of the transistor output (T). Hence you can adjust the requested mode acc. to 4.3 Functional schedule (see 3.2 Wiring plan ). The information to the position of the switch point (see 2.1 Mounting instructions ) relate to the measured product water (density 1,0 g/cm 3 ). In case of products with deviating density the switch point shifts dependent on density and installation kind to the direction of the housing of the tuning fork end. A density change by 0,1 g/cm 3 causes a shifting of the switch point by appr. 2,5 mm. A = max. level detection or overfill protection, B = min. level detection or detection against dry running of pumps. 4.2 Switch point The switch point of VEGASWING 71 A is preadjusted and does not require any modification. Switch point with lower density Switch point Switch point with higher density appr. 25 mm Fig Functional schedule The following schedule gives a survey on the switching conditions dependent on the adjusted mode and the level. Note 3.2 Wiring plan for selection of the mode. Mode A Mode B Response of Failure of the fault the supply monitoring voltage Level individual individual Transistor conductive blocks conductive blocks blocks blocks Signal lamp VEGASWING 71 A 11

12 Diagnosis 5 Diagnosis 5.1 Function test VEGASWING 71 A has an integral test switch which can be magnetically activated. Proceed as follows to test the instrument: Make sure that the tuning fork is uncovered. Hold the test magnet (accessory) to the magnet symbol on the instrument housing (see fig. 5.1). The test magnet simulates that the tuning fork is covered. The signal lamp of VEGASWING 71 A changes the condition. The electronics and the switching output of VEGASWING are now tested. Note that the connected instruments are activated during the test. When the full signal is correct, the VEGASWING operates without problems. If VEGASWING 71 A does not switch over after several tests with the test magnet, check the plug connection and the connection line and then test the instrument again. If there is no switching function, the electronics will be defect. In this case change the electronics (see 5.2 Exchange of electronics ) or send the instrument to our repair department. Note: It is absolutely necessary that you remove the test magnet from the instrument housing after the test had been carried out. Fig VEGASWING 71 A

13 Diagnosis 5.2 Exchange of electronics The instrument must not be dismounted to exchange the electronics in case of failure. Proceed as follows to exchange the electronics unit: Separate VEGASWING from power supply. Loosen the plug (1), by unscrewing it on the knurled ring. On VEGASWING 71 with fixed connected cable, the cable is fixed connected to the oscillator. It is hence necessary to exchange the cable with the oscillator. Loosen the plug insert (2) with a screwdriver on the four carves and remove it carefully from the housing (6). Pull the plug of the two connection cables (7) from the plug socket on the board (8). Grease the seal ring (4) of the new plug insert with an acidfree grease. Insert the connection cables (7) into the plug socket (8) on the board of the new oscillator. Shift the plug insert (2) into the housing. Note that the locking piston (3) is approx. above the chamfer on the housing edge (5). Press the plug insert (2) carefully from the top into the housing (6). Press the four snap hooks (9) with a screwdriver to the inside so that the plug insert can be more easily placed in the housing. Note that the board will not be damaged. Press the plug insert (2) flush to the housing (6). Note that the locking piston (3) snaps into the chamfer on the housing (5). The snap hooks (9) snap into the groove inside the housing. The parts can no more be loosened without damage. Screw the plug (1) again to the instrument. The VEGASWING is again ready for operation. Note that the switch point can slightly change due to the electronics exchange Plug 2 Plug insert 3 Locking piston 4 Seal ring 5 Chamfer 6 Housing 7 Connection plug 8 Socket 9 Snap hook (4 pcs.) Fig. 5.2 VEGASWING 71 A 13

14 Diagnosis 5.3 Maintenance VEGASWING 71 A is maintenance-free. 14 VEGASWING 71 A

15 Notes VEGASWING 71 A 15

16 VEGA Grieshaber KG Am Hohenstein 113 D Schiltach Phone ( ) 50-0 Fax ( ) Fax ( ) ISO 9001 Technical data subject to alterations / Oct. 96