XKC-Y25 NPN liquid level sensor: specs and pinout
A capacitive sensor that detects liquid through the wall of a flat container or large pipe without touching it. The XKC-Y25 family comes in V (voltage), NPN, PNP and RS-485 output versions; this listing is the NPN one.
Specs
| Spec | Value | Source |
|---|---|---|
| Input voltage (Vin) | DC 5 V to 12 V, or DC 24 V | source XKC-Y25 product page, catalogue p.13 (PDF page 14) |
| Output method | NPN, PNP, voltage (V) or RS-485, by version; NPN for this listing | source XKC-Y25 product page, catalogue p.13 (PDF page 14) |
| Consumption current | 5 mA | source XKC-Y25 product page, catalogue p.13 (PDF page 14) |
| Output voltage, high / low (voltage version) | Vin / 0 V | source XKC-Y25 product page, catalogue p.13 (PDF page 14) |
| Response time | 500 ms | source XKC-Y25 product page, catalogue p.13 (PDF page 14) |
| Working temperature | -20 C to 105 C | source XKC-Y25 product page, catalogue p.13 (PDF page 14) |
| Container wall thickness | 20 mm or less | source XKC-Y25 product page, catalogue p.13 (PDF page 14) |
| Induction accuracy | +/-1.5 mm | source XKC-Y25 product page, catalogue p.13 (PDF page 14) |
| Humidity | 5 % to 100 % | source XKC-Y25 product page, catalogue p.13 (PDF page 14) |
| Waterproof grade | IP67 | source XKC-Y25 product page, catalogue p.13 (PDF page 14) |
Power
| Value | Source | |
|---|---|---|
| Supply | DC 5-12 V or DC 24 V | source XKC-Y25 product page, catalogue p.13 (PDF page 14) |
| Current | 5 mA | source XKC-Y25 product page, catalogue p.13 (PDF page 14) |
Pinout
Pinout from the maker's XKC-Y25 page (wire colours Brown, Blue, Yellow; MODE selection). The sheet shows the family; the NPN version is the listing.
| Pin | Function | Voltage | Notes | Source |
|---|---|---|---|---|
| VCC (brown wire) | Supply | DC 5-12 V or 24 V | source XKC-Y25 product page, catalogue p.13 (PDF page 14), wiring diagram | |
| GND (blue wire) | Ground | 0 V | source XKC-Y25 product page, catalogue p.13 (PDF page 14), wiring diagram | |
| OUT (yellow wire) | Signal output (NPN version pulls to GND) | Load goes between supply and OUT on NPN versions | source XKC-Y25 product page, catalogue p.13 (PDF page 14), wiring diagram | |
| MODE | Normally open / normally closed (positive and negative output) selection | Wire colour not stated on the sheet | source XKC-Y25 product page, catalogue p.13 (PDF page 14), wiring diagram |
Build with it
Project ideas for the XKC-Y25 NPN liquid level sensor. Each link opens Soldr with the prompt filled in; Soldr assigns the pins, checks power and shows how to wire every part.
- Water tank level display: Sensor on 5 V; OUT only pulls to GND, so the ESP32 can use its own 3.3 V pull-up. Learning project.
- Low-water beeper: Uno 5 V powers the sensor and its pull-up reads the NPN output. Learning project.
- Tank refill pump control: The pump runs from its own supply through the relay, never from a board pin; keep wiring low-voltage.
Common mistakes
- Wiring an NPN output like a voltage output: the NPN diagram puts the load (relay) between supply and OUT, with the sensor pulling OUT to GND (source)
- Using a container wall thicker than 20 mm: the sheet specifies 20 mm or less (source)
- Expecting an instant reading: response time is 500 ms (source)
Not covered by the official source
- Sheet lists all four output versions together; some values (supply, current) may differ per version.
- Power supply ripple value is not given because the PDF figure is unclear.
- MODE wire colour not stated.
Sources
- link (Shenzhen XingKeChuang Technology catalogue, XKC-Y25 page; maker site www.xkc-sensor.com)