Current Loop Load Resistance Calculator
Estimate remaining series resistance from loop supply, transmitter minimum voltage, receiver burden, and other entered voltage drops.
Enter instrument values
Loop resistance budget
About this calculator
Estimate remaining series resistance from loop supply, transmitter minimum voltage, receiver burden, and other entered voltage drops.
Uses the entered maximum loop current and component drops as fixed values. Confirm transmitter compliance voltage, receiver burden, cable resistance, barriers, and any nonlinear device behavior from manufacturer data.
Method and assumptions
Available voltage for additional resistance = supply voltage − transmitter minimum voltage − receiver burden × maximum loop current − other entered drops. Maximum additional resistance is available voltage divided by maximum loop current; negative voltage margin is reported as insufficient.
Calculated results reflect only the ratios, spans, burdens, and readings entered. Verify instruments, wiring, polarity, configuration, and manufacturer limits independently.
FAQs
Can I open or disconnect a current transformer secondary while energized?
No. Never open an energized CT secondary. Follow approved electrical safety procedures and manufacturer instructions.
Does a calculated value verify billing or instrument configuration?
No. Confirm whether the meter or register already applies CT/PT scaling and verify the configured ratios with the metering documentation.
Sources
Use instrument nameplates, meter configuration records, transmitter setup data, and manufacturer compliance-voltage specifications for the installed equipment.