Monitoring

Traditional water spot (flood) detectors are inexpensive, easy to install, and popular in many industries. They typically use 2 or 4 pins, and water is detected when those pins are connected. The problem is that there must be a continuous layer of water to detect the presence of water. 

The spot water detectors should be installed with care and precision, at lower surface levels. In the real world, there is a high probability of a very late alarm. You will be alerted when everything is already flooded, just because a detector was placed where the water is coming from at the end of a flood disaster. We call this type of late warning a "swimming invitation", not an early warning. 

Businesses and industries where the detection and control of water and other liquids is critical know from experience the importance of early warning with the first few drops of water. The first few minutes are critical to preventing ultimate damage. 
Final damage is not the cleaning service and drying out of the building, but the company being out of business, damaged (unreliable) servers, etc.

	Spot water (flood) detection	Sensing cable water leak detection
System cost	Up to €100	From €400
Installation time	5 min	1 hour / zone
What is detected	Water layer (2mm min) on 2 contacts	First drops of water along the entire length of the sensing cable
Late alert (swimming invitation)	Highly likely	Unlikely
False alarm probability	Unlikely	Unlikely
Early warning	Unlikely	Highly likely

Water spot (flood) detection

Flood detectors only detect water in one location and must be completely flooded. This means that you will not be alerted immediately when a water pipe breaks, but only when the area is significantly flooded. Therefore, it is not the ideal solution for data centers etc. where you need to be alerted before the water reaches your IT infrastructure. 
Only the use of the water detection cable ensures this.

Using the Water spot detection:

• Easy to use detector
• High risk of improper installation
• Swimming invitation alerts only

 

Sensing cable water leak detection

Using Water Leak Detection with a sensing cable you can detect the first drops anywhere in the monitored room/area. This early warning can prevent significant damage to IT or other infrastructure. Water Leak Detection with sensing cable is recommended in IT, data centers, engineering and medical environments, or anywhere where water damage would be very costly.
A sensing cable can be installed under raised floors in data centers, wrapped around pipes, run along walls, etc. Custom solutions are available for any requirement.

Using the WLD sensing cable:

• Placement of the sensing cable must be considered
• WLD system is reliable (no false alarms)
• WLD system is capable of alarm
• Detects the first drops of water along the entire length of the sensing cable
• Sensing zone can be easily covered by combination of sensing & non-sensing cable

WLD system
The real early warning is exactly why having a water leak detection system in place, although much more expensive, is preferred by many. HW group's remote monitoring ecosystem includes several devices based on the unique sensing cable that detects even a few drops of water.

The WLD system works with zones, where each cable, installed even after construction or equipment setup, creates a conductive liquid monitoring zone.

WLD zone(s)

With such a zone, which could be up to 185 meters away from the monitoring device, one could create an effective detection situation by placing the sensing cable right next to the water sources in any type of site, be it a data center, industrial or manufacturing facility, or a warehouse.

With the much faster response to any water presence, this could mean preventing a disaster rather than arriving on site when the damage is already skyrocketing. With the WLD system, what you're buying is time and robust, easy installation within any existing infrastructure.

Early warning of water flooding

The whole idea of why to invest 1000 - 5000 Euro for water detection system against simple water spot detector is based on the assumption that if you react within first minutes, repair costs will be 10x lower compared to 10 cm of water in whole building. 

Every building has a certain capacity of water that can be easily cleaned. You just have to be quick.

In order to respond quickly, you must have:

1. Water sensing cables installed in the right places;
2. Properly configured devices analyzing WLD zones + Portal (optional);
3. Alert escalation + processes;
4. Test the whole system from time to time.

Choosing the Right Water Leak Detection Device

HW group's Water Leak Detection system consists of a WLD sensing cable and a connected alarming device. There are currently 4 different remote monitoring devices with WLD zone input(s). Let's take a look at the differences between them.

	WLD2	SD-WLD	NB-WLD	WLD-Relay
WLD zones	4	1	1	1
NB-IoT (Cellular network)	-	-	yes	-
LAN (RJ45)	yes	yes	-	-
Wi-Fi	yes	yes	-	-
1Wire-UNI (RJ11)	-	-	-	yes
Relay output (NO/NC)	-	-	-	yes

WLD2: Standalone Water Leak Detection

With 4 detection zone inputs (4x 185m of water sensing cable) and PoE / 5V power adapter, the WLD2 is the most universal water detection device. The WLD2 can send email alerts by itself or through an external Portal (SensDesk technology).

4 WLD zones means the WLD2 can detect / identify water in 4 independent areas. 

• Water detection in each zone can be indicated by: 
  • External Relay output (with or without Portal);
  • Email (with or without Portal);
  • SMS / Call (with SMS GW or with Portal).

When customers use the Portal (even free HWg-cloud.com), there can be activated "Device Invalid Alert" feature. The portal will alert you if there is no power / communication with the portal. 

Product web page: https://www.hw-group.com/device/wld2

SD-WLD

The SD-WLD is a simple Water Leak Detection device with only 1 WLD zone input. Powered by PoE / 5V power supply. The SD-WLD is easy to install, there is no local configuration required, but external Portal is mandatory. Device itself can't send alarm emails without Portal.

• SD-WLD can be powered by PoE;
• Portal connectivity is required;
• Portal provides centralized alert management (Email, SMS, Calls, SNMP, Relay Output);
• Portal provides "Device Invalid Alert" feature. The portal will alert you if there is no power/communication with the portal. 

Product web page: https://www.hw-group.com/device/sd-wld

NB-WLD

NB-IoT cellular connected device for remote monitoring of 1 WLD zone (60 / 185 meters of sensing cable). 3-year SIM contract included, battery operation for up to 2 years.
Powered by an internal battery / 5V power supply, the NB-WLD is an ingenious device to warn you, even if there is a power failure at the remote location. External portal is mandatory, device itself can't send alerting emails without the Portal.

• NB-WLD can be powered from internal battery for up to 2 years;
• When powered by internal battery, the maximum WLD zone length is 60m;
• Portal connectivity is required;
• Portal centralized alert management (Email, SMS, Calls, SNMP, Relay Output);
• Portal provides "Device Invalid Alert" feature. The portal will alert you if there is no power/communication with the Portal.

Product web page: https://www.hw-group.com/device/nb-wld

WLD Relay

The WLD Relay is a 1-WLD zone sensing device with 2 output options. Flooding can be indicated by a switching relay output or as a 1-Wire UNI (RJ11) sensor. Via RJ11 it can be connected to many HWg devices with external sensor ports.

• WLD Relay is a universal device (WLD detector) that can be connected to any security system or DI (Dry Contact) on the IP camera, etc;
• Water detection is indicated locally by red LED diode on the device. 

Product web page: https://www.hw-group.com/sensor/sensor-wld-relay-1w-uni

Alerting reality: Every minute counts

We are talking about long-term monitoring sensor installation. That means the customer installs a sensor, tests it, and it sits there quietly for 3-7 years. After that, you need to be alerted and "woken up" within 1-5 minutes. Every minute counts. Here are some best practices: 

• Test the system once a year, that's best practice; 
• Do not use public SMTP server for email alerting (use Portal or private SMTP server);
• Email is not enough;
• Use SMS / Calls for water alerting;
• Use proper names in the WLD zone names; 
• Try to figure out after 7 years what "server room C flooded" is when you're responsible for 3 locations;
• Centralized management (Portal) of alerts is much better; 
• Very few customers change the phone numbers/emails of the recipients in the devices.

 

	WLD2	SD-WLD	NB-WLD	WLD-Relay
SensDesk Portal Connectivity	Yes	Yes (mandatory)	Yes (mandatory)	Via external device
Web interface, SMTP	Yes	Via portal	Via portal	-
E-mail alert	Yes	Via portal	Via portal	-
SMS & Call alert	Via SMS Gateway or Portal	Via portal	Via portal	-
Disconnected device alert	Via portal	Via portal	Via portal	Yes (sensor = -999)
Remote relay alert	Yes	Via portal	Via portal	Via external device
Multigraphs, PDF reports	Via portal	Via portal	Via portal	-
Open API (SNMP, XML)	Yes	Via portal	Via portal	-

Summary of WLD System by HW group

WLD System from HW group will help any customer to safely monitor the remote site for very small amounts of water, and provide timely alerts via various mediums when the liquid is detected.

You can find more details in our summary “Water Leak Detection (WLD) system” article: https://www.hw-group.com/support/water-leak-detection-wld-system

Take a look at the video explaining all the different options of the WLD system.

WLD (Water Leak Detection) from HW group uses a sensing WLD cable to detect water along the entire length of the sensing cable. It’s a reliable system with early warnings from the very first drops of the water in the critical points.

HW group produces several devices with WLD zone input on the LAN devices (SD-WLD, WLD2, Perseus 150) or NB-IoT (NB-WLD). However, many customers want to use only WLD detection and connect it to their own system. For them we produce the WLD Relay, which can be powered by 12V and switches a simple relay output when water is detected.

WLD sensing cable features

It's hard to explain why the HW Group's WLD sensor cable is so popular. Our customers love it simply because this water leak detection cable does not generate false alarms.

• No Bend Limit

Most of the other water detection sensing cables are limited to a minimal diameter. If it bends too much, it will generate a false water alarm. It's a fundamental problem for many installations. 
The WLD sensing cable doesn't have a bend radius limit. It can be knotted and still work, which means installation is easy and doesn't require any special training. 

• No Grip Limit

Point pressure within a reasonable range won't change the functionality of the cable. You can step or press on the WLD sensing cable without triggering an alarm. It could even be routed over the door sill.

• No Twist Limit

Like any other electrical cable, the WLD sensing cable can be twisted. No twist limit for the WLD sensing cable also means that no cable movement after installation will cause a false alarm.

• No Reuse Limit

Once the liquid has been detected and hopefully stopped from flooding the monitored facility, the cable simply dries out and resumes its primary function.

Water detection on 185m sensing cable with relay output

The WLD Relay has 1 WLD zone input with a green terminal block. A WLD connection cable (2m) and one or more segments of WLD sensing cable are connected. The total length of the WLD zone can be up to 185 including the length of the non-sensing cable. 

Relay output responds to the smallest amount of water, ethylene glycol or other conductive liquid water along the entire length of the sensing cable. The relay will also alarm if the WLD sensing cable is disconnected. 

The WLD relay requires a 12V power supply.

WLD-Relay as RJ11 sensor

The same device WLD-Relay can also be used as RJ11 (1W UNI) sensor. A WLD zone can be connected to any HWg device with an RJ11 port (STE2 family, Poseidon2 family, Ares 12, ...). 

The WLD Relay as 1W-UNI sensor supports three states: 

• OK
• Water 
• Disconnected

This means that the operator of the remote monitoring solution would know if something has happened to the cable itself or if there is water flooding. There would be no surprise leakage if the cable were accidentally broken or disconnected.

 

WLD relays can be ordered as:

• Sensor WLD Relay 1W-UNI 

Plain unit - white box only. 

• WLD Relay 

Set with power supply, 2m + 2m WLD sensing cable

WLD-Relay in action - 1200 meters of WLD sensing cable

WLD relay can be massively scaled, as we have shown in the ONSEMI case study, where the water monitoring system counts 28 relay-based zones with a total of more than 1200 meters of sensor cable. All of this is connected to a single Damocles2 monitoring unit responsible for alarming and alerting.

Take a look at the video we made about the WLD Relay.

Let's take a look at some of the most popular sensor and detector options used by professionals for environmental monitoring.

- The sensors are connected to the RJ11 (1-Wire) or RJ45 (RS-485) port. The sensors provide a continuous value of, for example, -23.4°C or 32.7% RH. Device monitoring (SensDesk Portal) can monitor the safe range of values and send an email or SMS alert if the value changes outside the range. You can only use sensors from the HW group.
- Converters and Expanders allow you to connect other types of buses or interfaces to standard monitoring HW group devices. Converters use a continuous value (0-10V / 4-20 mA) as input.
- The Detectors you connect to a DI input (green connector) provide a value of 0/1. A typical example is a smoke detector with a relay output or a door opening detector (door open/closed). The monitoring device (SensDesk Portal) can monitor the switching to the alarm value and send an e-mail or SMS alarm. 
Detector in this definition is a global product. You can connect detectors with relay output from any manufacturer to the DI input of any HW group' device.

60m for RJ11 (1-Wire) / 1000m for RS-485

When talking about sensors, there are two widespread options available from HWgroup, with a significant difference: RJ11 (1-Wire), which allows a maximum distance of 60 meters per RJ11 port between the sensor and the device. The RS-485 standard, which allows a maximum distance of 1000 meters.

This particular difference between these two types of standards makes RS-485 a perfect candidate for industrial-scale monitoring projects, while the fully auto-detecting RJ11 option is better suited for smaller projects such as data centers or warehouses.

Temperature for Cryo / Fridges

Temperature sensors, based on 1-Wire or RS-485, are needed in many niches where it is necessary to monitor precise environmental conditions: cryo storage for pharmaceutical use, refrigerator temperature in shops and warehouses, and many, many more potential applications.

HW group offers special temperature sensors for any application where there are strict requirements for the monitored environment. That's why we produce a RJ11 (1-Wire) based PT100 Frost temperature sensor, specially designed for those situations where an accurate value in the range of -200°C to +160°C needs to be monitored.

Temperature sensor with flat cable for easy installation

The Temp-1Wire-Flat is a unique temperature sensor designed for use in refrigerators. Special flat cable allows it to be bent around a refrigerator and fixed in the doors. There is no need to drill the refrigerator housing and the installation is quite easy and quick. Cable is designed for 1000 cycles of opening and closing of refrigerator doors.

Outdoor / Indoor Temperature & Humidity combined sensors

In addition, HW group produces a wide variety of outdoor and indoor combined sensors, where the customer can have up to 4 sensor values in one package - as is the case with our THPVoC sensor, which provides 4 monitored values in one slick package: Temperature, Relative Humidity, Barometric Pressure and VOC (Volatile Organic Compounds). This is the best possible combination when you need a small but versatile indoor sensor package.

Outdoor relative humidity sensor

With our outdoor sensors, such as the HTemp-1-Wire Outdoor Sensor, you can measure both temperature and relative humidity at the same time without worrying about outdoor conditions. This sensor works in the temperature range of -30 to 85°C, which allows it to be used outdoors. In addition, this particular outdoor sensor is useful if you need to calculate the dew point - a value that is very important in some applications, such as vineyard monitoring.

Converters (60V / 0-20mA / 4-20mA)

Converters allow users to connect analog type of probes (sensors) to standard monitoring HW group devices. 

HW group manufactures three different types of converters for use with our devices. The values can be exchanged via LAN or GSM. When the current is out of a specified range, an email or SMS is sent. Can be connected to remote monitoring systems based on SNMP or Modbus/TCP.

60V 1Wire-UNI
Galvanically isolated voltage sensor up to 60VDC with 1Wire-UNI output. Typical applications include measuring the voltage of industrial sensors (0-10V) or battery voltage. Often used to measure 48V power supplies in telecommunications (48V standard). 

High accuracy allows use for 0-10V applications, sensors can be daisy chained using two RJ11 connectors. This converter is powered from the 1Wire-UNI bus or an external power supply.

0-20 mA 1Wire-UNI
Isolated DC current sensor for 1Wire-UNI bus. Sensor for measuring currents in the 0-20mA range. It is typically used to connect an industrial probe with 0/4 to 20mA output - with a discrete power supply (e.g. to measure fuel level in a tank).

Sensors can be daisy-chained using two RJ11 connectors. The converter is bus powered via 1Wire-UNI interface, which means that a maximum of 2 sensors are allowed per active port.

40-20 mA 1Wire-UNI
Isolated DC current sensor for the RJ11 1W-UNI bus. It's a RJ11 powered converter for external 4-20mA probes. It is typically used to connect an industrial probe with 4-20mA interface - 2wire current loop ("sink" type).

It can be daisy chained using two RJ11 connectors. An external 12-30V power supply is recommended with this converter.

Sensor wiring - Daisy chain Box2 / Rack19” sensors

HW group offers the technical possibility to daisy-chain the sensors for longer or more complex installations. Our Box2 and Rack19" sensors can be daisy-chained with a total length of 60 meters from the first connected RJ11 port. This is the reason why, for example, Poseidon2 4002, while having 6 RJ11 ports (up to 16 sensor values), can be daisy-chained.

Sensors calibration features

The USB calibrator helps you to adjust measured values for most of sensors. 

If you want to connect a third party (analog) sensor to HWgroup's device via RJ11, you would need the USB calibrator. For example, a radar distance sensor with 4-20mA analog output. Using the USB calibrator, you can define 4mA = 1m distance and 18mA = 5m distance. The whole ecosystem of the HW group will later display the distance in meters and would no more use the mA values. 

The conversion doesn't have to be linear, there is a matrix for 8 values.

Summary

HW group manufactures a wide range of wired sensors for every possible application. And with the help of the USB calibrator and converter, it is possible to connect almost any other third-party sensor to the HW group monitor. And with daisy-chaining, a large number of sensors can be installed in a project of any size or market specificity.