The Omron 61F-GPN-V50 AC100 is a leak detection controller from the 61F series, running on a 100VAC supply. It's the part you grab when a sump pit, condensate tray, or coolant tank needs a reliable liquid-level watchdog — no float, no moving parts in the tank, just a probe sensing conductivity through the liquid.
The adjustable sensitivity range of 0 to 50 kOhm is the key spec for a field fix. That span covers most conductive liquids — tap water, coolant emulsions, waste water — but if you're dealing with deionized water or a high-resistivity fluid, this controller may not trigger reliably. Set it low for clean water, higher for dirty or oily sumps. It's a dial, not a guess. Output is a single SPDT relay (2 Form C) rated 3A at 250VAC. That's enough to kick a small pump contactor, sound an alarm, or signal a PLC input. Don't plan on switching the pump motor directly above fractional horsepower — use it as the pilot relay and let a contactor handle the motor current. Termination is via an 11-pin octal socket — the standard footprint for this class of controller. If the panel already has a socket wired for a 61F or similar octal-base relay, this drops right in. No rewiring the gland plate.
Socketable mounting means the controller body plugs into a base that stays on the DIN rail or panel. Swap the controller in seconds without disturbing the field wiring — exactly what you want when a line-down call comes in and the spare is on the van. Operating range is -10°C to 50°C, fine for a ventilated enclosure but not for a steam pit or unheated outdoor cabinet in a hard freeze.