GE 469 Instruction Manual

Also see for Masoneilan 469 Series: Instruction manual Instruction manual Communications guide Instruction manual Instruction manual

Contents

3–20 469 MOTOR MANAGEMENT RELAY – INSTRUCTION MANUALCHAPTER 3: INSTALLATIONIf a voltage output is required, a burden resistor must be connected at the input of theSCADA measuring device. Ignoring the input impedance of the input, R load = Vfull scale / I max.For 0 to 1 mA, for example, if 5 V full scale is required to correspond to 1 mA, R load = 5 V /0.001 A = 5000 Ω. For 4 to 20 mA, this resistor would be Rload = 5 V / 0.020 A = 250 Ω.3.2.9 RTD Sensor ConnectionsDescriptionThe 469 monitors up to 12 RTD inputs for Stator, Bearing, Ambient, or Other temperaturemonitoring. The type of each RTD is field programmable as 100 Ω Platinum (DIN 43760),100 Ω Nickel, 120 Ω Nickel, or 10 Ω Copper. RTDs must be three wire type. Every two RTDsshares a common return.The RTD circuitry compensates for lead resistance, provided that each of the three leads isthe same length. Lead resistance should not exceed 25 Ω per lead for platinum/nickelRTDs or 3 Ω per lead for copper RTDs. Shielded cable should be used to prevent noisepickup in the industrial environment. RTD cables should be kept close to grounded metalcasings and away from areas of high electromagnetic or radio interference. RTD leadsshould not be run adjacent to or in the same conduit as high current carrying wires.FIGURE 3–22: RTD WiringNoteIMPORTANT: The RTD circuitry is isolated as a group with the Analog Input circuitry andthe Analog Output circuitry. Only one ground reference should be used for the threecircuits. Transorbs limit this isolation to ±36 V with respect to the 469 safety ground.Reduced RTD Lead Number ApplicationThe 469 requires three leads to be brought back from each RTD: Hot, Return andCompensation. This can be quite expensive. It is however possible to reduce the number ofleads required to 3 for the first RTD and 1 for each successive RTD. Refer to the figure belowfor wiring configuration for this application.MOTORSTARTER MOTOR3 WIRE SHIELDED CABLERTDTERMINALSIN MOTORSTARTERRTD TERMINALSAT MOTORMaximum total lead resistance25 ohms (Platinum & Nickel RTDs)3 ohms (Copper RTDs)Route cable in separate conduit fromcurrent carrying conductorsRTD INMOTORSTATORORBEARING806819A5.CDRB1A1A2A3HOTCOMPENSATIONRETURNSHIELDCHASSISGROUNDRTD SENSINGRTD #1469RELAY