The EM15-221 combines a sealed mercury tilt switch with a polypropylene float and a suspended cable. Changes in liquid level tilt the float, moving mercury inside the contact element to provide upper- or lower-level signals. The approximately ±10° operating angle supports sensitive indication in tanks, reservoirs, pits and compatible industrial-liquid containers.
Use the signal with a suitable receiving controller or external relay. Multiple float switches can provide separate level inputs for pump interlocks, alarms or multi-point monitoring. The float circuit must stay within its 24VAC/DC and 0.5A limits.
| Parameter | Specification |
|---|---|
| Switch element | Mercury tilt switch |
| Operating voltage | 0–24VAC/DC |
| Maximum current | 0.5A |
| Working temperature | 0–80°C |
| Float housing | Polypropylene |
| Cable construction | Silicone insulation with copper conductors |
| Conductor area options | 0.5mm² or 1.0mm² |
| Cable lengths | 5m, 10m or 20m; custom lengths available |
| Operating angle | Approximately ±10° |
| Float-body density | 0.34g/cm³ |
| Maximum pressure | 0.3MPa |
| Protection rating | IP65 |
| Recommended level difference | Greater than 0.4m for stable operation |
| Conductor | Function |
|---|---|
| Black | Common |
| Blue | Lower-level signal for filling; closes to common at approximately −10° |
| Brown | Upper-level signal for drainage; closes to common at approximately +10° |
The switch retains its previous contact state between −10° and +10°. Select the required signal wire and fully insulate the unused conductor. For a larger load, use a relay and contactor arrangement that keeps the float contact circuit within its voltage and current limits.
Pass the cable through the recessed opening in the counterweight. Set the free length between float and weight to approximately 0.7 times the required high-to-low liquid-level difference. Provide clearance for unrestricted motion and check both switching states before service.
Use liquids compatible with the polypropylene housing, cable and sealed assembly. Isolate power before installation, keep cable joints dry and inspect the housing and insulation regularly. Stop using a damaged, deformed or leaking switch. The mercury contact element requires hazardous-waste handling at end of life.
