Appendix B
VPR & VRX – User Manual
12/00
300
Inductive coils, continued
Figure Appendix B-2 is an illustration of transient suppression in inductive coils.
Metal
oxide
varistor
A.C.
supply
Relay coil
or
solenoid
0.5 mfd
1000V
220
ohms
20780
Figure Appendix B-2 Transient Suppression in Inductive Coils
Additional protection may be provided by adding an RC circuit in parallel with the MOV. This consists of a
220-ohm resistor in series with a 0.5 microfarad, 1000V capacitor. The power rating of the resistor will
depend on the voltage rating of the coil (see Table Appendix B-3).
Table Appendix B-3 Coil Voltage vs. Resistor Voltage Rating
Coil Voltage
Resistor Voltage Rating
115V
1/4 Watt
230V
1 Watt
460V
3 Watt
550V
5 Watt
Continued on next page
Summary of Contents for VPR100
Page 1: ...Sensing and Control VPR100 VRX100 VRX150 User Manual 57 77 25 15 Rev 4 12 00 ...
Page 16: ...xvi VPR VRX User Manual 12 00 ...
Page 198: ...Programming Function Blocks and Features VPR VRX User Manual 12 00 182 ...
Page 248: ...Online Operations Using Primary Displays VPR VRX User Manual 12 00 232 ...
Page 292: ...On Site Adjustments VPR VRX User Manual 12 00 276 ...
Page 300: ...Parts VPR VRX User Manual 12 00 284 Figure 11 3 Components of portable case ...
Page 301: ...Parts 12 00 VPR VRX User Manual 285 Figure 11 4 Exploded view of VPR VRX100 display ...
Page 305: ...Parts 12 00 VPR VRX User Manual 289 Figure 11 9 Module for Two Additional Analog Inputs ...
Page 306: ...Parts VPR VRX User Manual 12 00 290 ...
Page 308: ...Appendix A VPR VRX User Manual 12 00 292 ...
Page 320: ...Appendix B VPR VRX User Manual 12 00 304 ...
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