HNL01-A Photoelectric Liquid Leak Sensor for Water Leak Detection

HNL01-A Photoelectric Liquid Leak Sensor for Water Leak Detection

Photoelectric liquid leak sensor, 940 nm infrared, NPN/PNP output, 10–30 VDC, 100 mA, PFA housing, PTFE cable, IP67, −25 to 70 ℃, 2 m cable.

HNL01-A Photoelectric Liquid Leak Sensor for Water Leak Detection

The HNL01-A photoelectric leak sensor detects water and other liquid leakage and accumulation close to the point of risk. The sensing element uses 940 nm infrared light, so detection is not affected by ambient visible light. Reverse-polarity and short-circuit protection give reliable operation in industrial panels and cabinets. The compact sensor works against both metal and non-metal mounting surfaces.

INQUIRY

Leak and Spill Detection Under Pumps, Trays and Cabinets

Suited to electrical cabinets and control panels, pump drip trays and base plates, machine tool coolant and lubricant leak detection, cleanrooms and semiconductor fabs, server rooms and data centres, chemical storage and dosing areas, HVAC condensate and drainage, water treatment and pumping stations, laboratory and medical equipment, battery and energy storage enclosures, food and beverage wash-down areas, and industrial automation leak and spill alarms.

Good fit: electrical cabinets and panels, pump drip trays and base plates, machine tool coolant/lubricant, cleanrooms and fabs, server rooms and data centres, chemical storage and dosing, HVAC condensate and drainage, water treatment and pump stations, lab and medical equipment, battery/energy storage enclosures, wash-down areas, leak and spill alarm.

Is HNL01-A Suitable for Your Application?

Choose HNL01-A when:

You need a compact point sensor that detects water or other liquid collecting under a pump, at the bottom of an enclosure, in a drip tray or along a pipe gallery.
The sensor must mount on a metal or non-metal plate and withstand a wet, wash-down or chemically aggressive environment.
You need NPN or PNP switching output to shut equipment down or trigger an alarm after leakage.

Confirm with us first when: the detected liquid is an aggressive chemical not covered by the PFA/PTFE rating, the mounting surface is uneven or coated with residue, or the required output logic differs from NPN/PNP.

Design and Functions

Infrared sensing

The 940 nm infrared light source detects leakage without interference from ambient visible light. The operating state is normally OFF/ON and switches ON/OFF when leakage is detected, so the output logic can be matched to the control scheme.

Indicators and protection

Green LED for power, yellow LED for output. Reverse-polarity protection and short-circuit protection are built in. The 2 metre PTFE cable provides chemical resistance and reliable sealing in wet service.

Wet-environment materials

PFA housing with IP67 protection and PTFE cable, a combination chosen for chemical resistance and reliable sealing in wet, wash-down or chemically aggressive environments.

Technical Specifications

Model	HNL01-A — Photoelectric liquid leak sensor
Mounting surface	Metal or non-metal plate
Detectable object	Water (standard)
Light source	Infrared 940 nm
Operating state	Normally OFF/ON; ON/OFF when leakage is detected
Output function	NPN or PNP
Indicators	Power indicator green LED; output indicator yellow LED
Connection	2 metre cable
Protection	Reverse-polarity protection: yes; short-circuit protection: yes
Working temperature	−25…+70 ℃, no condensation or frost
Operating voltage	10–30 VDC
Maximum load	100 mA
Residual voltage	≤1 V at a load current of 100 mA
Housing material	PFA
Protection rating	IP67
Cable material	PTFE
EMC immunity	Immunity >3 V/m; EFT >1 kV; ESD >4 kV (contact)
Mechanical ratings	Shock test per IEC 60947-5-5 Part 7.4.1; vibration test per IEC 60947-5-2 Part 7.4.2

Electrical Connection

Wire color	Terminal	Function
Brown	1 (+)	Supply positive, 10–30 VDC
Black	4 (A)	Output (NPN/PNP, switching state per order)
Blue	3 (−)	Supply negative

Three-wire connection; green LED indicates power, yellow LED indicates output switching.

Ordering Options

Option	Available choices
Output type	NPN or PNP
Output state	Normally OFF/ON or ON/OFF on leakage, matched to the control scheme
Cable	2 metre PTFE cable standard

Formal selection codes are not listed in the source brochure; confirm the output type and switching state with us when ordering.

Dimensions

Compact round detection head Ø25 mm with side mounting ear and LED indicator; two Ø4.5 mm mounting holes, 18 mm hole spacing, 26 mm overall width. Detection section thickness 9.9 mm; mounting height 16.5 mm / 7.5 mm, base dimensions 5 / 8.1 / 10.6 mm. Cable 2000 mm long, Ø2.9 mm AWG28.

Item	Dimension
Detection head	Ø25 mm
Mounting holes	2 × Ø4.5 mm; spacing 18 mm; width 26 mm
Mounting height	16.5 mm / 7.5 mm
Detection section	Thickness 9.9 mm; 5 / 8.1 / 10.6 mm
Cable	2000 mm; Ø2.9 mm AWG28

Installation Notes

Mount the sensing face flat against the lowest point where liquid collects, such as a drip tray, enclosure bottom or base plate, so any leakage reaches the face. Keep the face free of oil film, scale and residue that could mask the optical detection. Route and secure the PTFE cable away from moving parts; seal the cable entry where wash-down occurs.

Typical Applications

Electrical and IT: control panels, cabinets, server rooms and data centres.
Machinery: pump drip trays, machine tool coolant and lubricant leaks, hydraulic base plates.
Process and clean rooms: chemical storage and dosing, cleanrooms and semiconductor fabs, lab and medical equipment.
Utilities and storage: HVAC condensate and drainage, water treatment and pump stations, battery and energy storage enclosures, wash-down areas.

What to Send Us for Selection

Send: detected liquid, mounting surface material, required output (NPN/PNP) and switching logic, cable length, ambient temperature and any wash-down or chemical exposure. We will confirm the suitable version before quoting.

Frequently Asked Questions

Can it detect leaks on metal surfaces?

Yes. The sensor works against both metal and non-metal mounting plates; the 940 nm infrared sensing face detects liquid collecting on the surface regardless of the plate material.

How quickly can photoelectric sensing identify water beneath a process pump?

The infrared element reacts when liquid reaches the sensing face; the output switches to the selected ON/OFF state and the yellow output LED indicates detection. Response depends on how quickly the leak reaches the face, so place the sensor at the lowest collection point.

Are PFA housing and PTFE cable suitable for corrosive leaks?

The PFA housing and PTFE cable are chosen for chemical resistance and sealing in wet or aggressive service. For a specific aggressive chemical, send us the liquid name and concentration so we can confirm compatibility.

Can PNP or NPN output shut equipment down after leakage?

Yes. Select NPN or PNP to match the PLC or relay input, and set the normally OFF/ON or ON/OFF state so leakage triggers the alarm or shutdown interlock.

What cleaning prevents residue from masking the optical face?

Keep the sensing face free of oil film, scale and dried residue; clean it according to the maintenance interval of the installation. A coated or fouled face can cause missed detection or false output.