Ladder logic interpreter

A close permissive, built from named protection elements. Toggle the inputs and watch the close coil.

What is sourced, and what is this tool's own work. The 86 latch truth table below is published (GE Multilin 850, Non-volatile Latch, p4-414) and is reproduced exactly. The close permissive that combines the elements is this tool's own construction from those named parts. It is verified as self consistent boolean logic, not as any one vendor's factory scheme, because none was sourced. The tool refuses to name one it did not read.

Close permissive

The rung no 50 or 51 trip is written NOT(50 OR 51). De Morgan makes it equal to (NOT 50) AND (NOT 51); the interpreter shows both forms agree for the current inputs.

The 86 latch, on its own

A lockout relay is a latch. Set it with a trip, and it HOLDS with no input. Reset dominant means a reset always wins, so an operator can always clear it. The output survives a reboot, which is what a hand reset lockout does.

SetResetOutputMeaning

GE Multilin 850 Feeder Protection System Instruction Manual v2.0x (2017), Non-volatile Latches, p4-414, Reset Dominant. Read at a distributor mirror; the current v4.3x is login walled and unread. A latch truth table is a logic primitive, so the stale revision risk that applies to a setpoint does not apply here.

25 advance angle (sourced example)

One published worked example for the sync check timing.

SEL, Fundamentals and Advancements in Generator Synchronizing Systems (M. J. Thompson, 2012), p5. advance angle = slip x 360 x CBCT. Read at the SEL CDN. Shown as its own panel, not wired into a defaulted in sync verdict, because no relay default was read at a current publisher copy.

What this tool refuses