Masoneilan SVI II ESD Installation and Maintenance Manual =| 175© 2016 General Electric Company. All rights reserved.Compliance Voltage in Single Drop Current ModeSVI II ESD requires 9.0 V at 20 mA and 11.0 V at 4 mA. Typical smart devices require MOREVoltage at higher current. The controller supplying the current has LESS voltage available athigher current. SVI II ESD is unique in that it requires LESS voltage at higher current, whichcompliments the characteristic of the source requiring only 9 V at 20 mA.CAUTION Improperly or inadequately grounded installations can causenoise or instability in the control loop. The internal electronics areisolated from ground. Grounding the case is unnecessary forfunctional purposes but grounding the case may be necessary toconform to local codes.Table 32 through Table 34 provide examples of several SVI II ESD installations and compliancevoltage calculation necessary to supply 9 V at 20 mA.1 Such as MTL HCU16AOConclusion: Control system must have a compliance voltage equal to or greater than 17.64 V;contact the DCS vendor to verify compliance.Conclusion: Compliance voltage is not an issue because the Isolator provides all thenecessary voltage.Table 32 Compliance Voltage for Single Channel Zener with 22 AWG Cable InstallationVoltage at SVI II ESD at 20 mA 9.0 VDrop in single channel Zener barrier with 342 Ohms end to end resistance 6.84 VDrop in 22 AWG cable, 3000 ft. long (30 Ohms per 1000 feet) 1.8 VDrop in passive HART® Filter 1 0.0 VVoltage required at controller 17.64 VTable 33 Compliance Voltage for Galvanic Isolator with 22 AWG Cable InstallationVoltage at SVI II ESD at 20 mA 9.0 VDrop in 22 AWG cable, 3000 ft. long (30 Ohms per 1000 feet) 1.8 VRequired voltage at Isolator 10.8 VVoltage available from Isolator rated to drive 22 mA into 700 Ohms 13.2 VVoltage required at controller Not applicable - Isolatorsupplies the power
