EM15 float switches use a rolling-ball mechanism to actuate a microswitch as the float tilts with the liquid level. The contact signal controls tank filling, drainage, level alarms or pump interlocks in water-storage, irrigation and compatible industrial-liquid systems.
The polypropylene float has an injection-molded seal and a flexible cable. Position the counterweight to set the operating differential and leave enough clearance for the float to move without catching on the tank or piping. Typical control differentials are greater than 30cm.
| Version | Cable | Operating temperature | Voltage rating |
|---|---|---|---|
| EM15-2 standard | PVC / composite PVC, 3×0.5mm² | 0–70°C | 250V |
| EM15-2 reinforced | PVC / composite PVC, 3×1mm² | 0–70°C | 400V |
| EM15-2 / EM15-2A rubber | Rubber, 3×1mm² | 0–80°C | Up to 220V |
| EM15-2 / EM15-2A silicone | Silicone, 3×1mm² | 0–80°C | Up to 220V |
| EM15-5 teardrop | Composite PVC, 0.75mm² | 0–80°C | 250V |
| EM15 plug-in | PVC, 0.75mm² | 0–65°C | Up to 220V |
| Spring Garden anniversary | Composite PVC, 0.75mm² configuration | 0–70°C | 220V |
The standard cable-length choices are 2m, 3m, 4m, 5m and 10m, with custom lengths available. The anniversary version uses a green-and-pink float. The EM15-5 teardrop body provides smooth movement and a surface that reduces fouling in compatible water and wastewater service.
| Parameter | Specification |
|---|---|
| Switch | Three-terminal microswitch with changeover contacts |
| Rated-current choices | 4A, 8A or 12A according to the supplied configuration |
| Thermal-current choices | 10A or 16A at 250V, version-dependent |
| Electrical life | ≥110,000 operations |
| Float density | 0.69g/cm³, excluding the cable |
| Maximum pressure | ≤0.3MPa |
| Protection | IP68 float assembly |
| Conductor | Oxygen-free copper |
| Actuation angles | Drainage 40°; filling -55°, tolerance ±5° |
| Minimum control differential | ≥0.3m for the rectangular EM15-2 specification |
| Insulation resistance | ≥100MΩ |
| Dielectric withstand test | 1500V for 1 minute |
| Rectangular-body dimensions | 161mm overall length including cable entry; 105mm principal body length; 80mm width; 43mm thickness |
| EM15-2 conductor area | Nominal supported pump power | Full-load power entry |
|---|---|---|
| 0.5mm² | 750W | 880W |
| 0.75mm² | 1000W | 1320W |
| 1mm² | 1500W | 1760W |
Match the actual switch rating, cable, voltage and motor starting duty before connecting a load. Use a contactor for pump loads above 500W or whenever the load exceeds the instrument marking. The thermal-current figure is separate from the contact switching rating. A control voltage of 36V or less is recommended through the float where the control system permits.
| Connection | Float high | Float low |
|---|---|---|
| Common + blue: filling | Open | Closed |
| Common + brown: drainage | Closed | Open |
The cable's common is identified as black or yellow-green depending on the supplied version. Verify the instrument identification with power isolated and distinguish the switching common from protective earth. Fully insulate the unused conductor and protect all joints from moisture and condensation.
The plug-in configuration has a rated operating range of 0–65°C and a load entry below 1000W. Match the pump, plug pattern and complete assembly rating. Keep the supply plug and socket dry and outside the liquid.
With power isolated, pass the cable through the counterweight and set the free length to approximately 0.7 times the desired high-to-low level difference. Secure the cable, check unrestricted float movement and test the selected filling or drainage action.
Use compatible clean water or weakly corrosive liquids. Avoid strong acids, strong alkalis and organic solvents. Inspect the housing, seam and cable regularly; replace damaged parts and avoid cutting, puncturing or pulling on the seal. These switches are for ordinary locations and do not provide explosion protection.
Typical carton quantities are 40 pieces for 2m/3m cables, 30 for 4m/5m cables and 20 for 6m/7m/8m cables. Specify the cable material, area, length, float form and marked load when ordering.
