G1 float switches use a magnetic float to actuate a reed contact inside a stainless steel stem. The 1in threaded mounting provides a substantial tank connection, with BSP or NPT options selected to match the installation. Choose a single float for one sensing point or a double float for upper and lower level signals.
The standard float and stem are 304 stainless steel, with 316 stainless steel available by selection. Welded construction supports installation in water tanks, cooling systems, industrial reservoirs and compatible liquid-handling equipment.
| Parameter | 1A1 | 2A1 |
|---|---|---|
| Maximum contact rating | 10VA | 50VA |
| Maximum switching voltage | 100VAC/DC | 220VAC/DC |
| Maximum switching current | 0.5A | 1.5A |
| Breakdown-voltage reference | 110VAC/DC | 300VAC/DC |
| Maximum contact resistance | 100mΩ | 100mΩ |
| Operating temperature | −30–120°C | −30–120°C |
| Enclosure protection | IP65 | IP65 |
Respect contact power, voltage and current limits simultaneously. Select the actual enclosure construction for any higher protection requirement. Use a receiving relay for solenoid valves or alarms and a relay plus a contactor matched to the pump for pump control.
| Dimension | All G1 single- and double-float models |
|---|---|
| L1 | 32mm |
| L2 | 28mm |
| L3 | 8mm |
| H3 | 15mm |
| H4 | 23mm |
| H5 | 28mm |
| Mounting thread | 1in BSP or NPT by selection |
Dimensions are in mm and follow the symbols in the downloadable single- and double-float drawings. Both configurations have L1=32, L2=28, L3=8, H3=15, H4=23 and H5=28. The drawing’s thread label “1寸” means 1in. Confirm BSP or NPT when ordering.
| Single-float model | Double-float model | H1 | H2 |
|---|---|---|---|
| G1-100 | G1-100-2 | 123 | 100 |
| G1-150 | G1-150-2 | 173 | 150 |
| G1-200 | G1-200-2 | 223 | 200 |
| G1-250 | G1-250-2 | 273 | 250 |
| G1-300 | G1-300-2 | 323 | 300 |
| G1-350 | G1-350-2 | 373 | 350 |
| G1-400 | G1-400-2 | 423 | 400 |
| G1-450 | G1-450-2 | 473 | 450 |
Custom stem lengths, float counts, double-float spacing, threads and cable lengths are available. Specify the required switching elevations separately from the overall assembly dimensions.
In the standard below-closed arrangement, the contact opens as the liquid rises and the float moves away from its reed-switch position. It closes when the liquid falls and the float returns. Reversing the float changes the closed-state orientation; check continuity in both positions before commissioning.
For a two-level filling system, the lower level provides the start signal and the upper level provides the stop signal. For drainage, the upper level provides the start signal and the lower level provides the stop signal. The receiving control circuit must implement the required operating sequence and use the actual switch wiring and relay terminal assignments.
The two-level circuit uses a 14-pin relay with a self-holding auxiliary contact. Its 220VAC example requires a 220VAC-rated float option, a matching relay coil and the specified terminal arrangement.
| Relay connection | Function |
|---|---|
| 10–13 jumper | Live supply at 10 and coil terminal 13 |
| 11 | Neutral supply and float common |
| 12–14 jumper | Auxiliary contact common and coil terminal 14 |
| 14 | Start-signal lead |
| 8 | Permit / stop-signal lead |
| 6 and 7 | Switched load connections |
Select the actual relay or contactor for the load rating. For filling, the lower switch starts operation and the upper switch stops it. For drainage, the upper switch starts operation and the lower switch stops it. Set the float orientation and signal assignment accordingly; the English circuit attachment shows both operating sequences.
Use with water, light oils, coolants and other liquids compatible with the selected stainless steel, seals and cable. Avoid heavy sludge and large floating debris that can obstruct travel. Confirm temperature, pressure, mounting direction, thread, stem length, cable and switching logic before ordering. Install with free float movement and test the complete control sequence before operation.
