Water detector SHT 5002

Functional description

The water detector / level controller SHT 5002 is a powerful module, which ready for connection ensures that in a container, tank, garden pond, pool, etc. a level is maintained at the desired level. The SHT 5002 is controlled by two mini float switches, which are used to set the lower and upper level. In principle, this also works with water sensors. However, since these have a higher tendency to false alarms or a less accurate shutdown behavior (dry run protection) and are also wearing parts, we recommend our mini-float switches, because one of the two is almost always in the water. Sensors are permanently suitable only for regularly dry environments such as floors and surfaces.

Filling or emptying?

The "Fill" or "Empty" function is defined with a wire jumper on the SHT 5002 and has a direct effect on the switching behavior of the potential-free changeover relay.

Filling

If the water level drops below the lower level, the relay switches and the pump is activated. It remains active and pumps until the upper level is reached. Then the relay switches the pump off again and, e.g. in a pond, so much water can evaporate again until the lower level is reached again.

Empty

When the water level reaches the upper level, the relay switches and the pump is activated. It remains active and pumps until the lower level is reached. Then the relay switches the pump off again and the tank can fill itself again, e.g. due to rain.

Level control

The SHT 5002 water detector is a device for level control (2-point controller). An upper and a lower level is defined via two mini float switches and can be used for automatic filling or emptying of a tank. A potential-free relay contact is used to control the pump.

Overflow message

In addition, the SHT 5002 water detector offers a further input (with two connections in parallel) for an overflow message (e.g. in the event of pump failure) with potential-free relay contact. In this way, for example, a signal transmitter, a solenoid shut-off valve, a telephone dialer or even a bus system (bus switch-on module) can be controlled. Water sensors are also very suitable for overflow detection when the overflow spills onto regularly dry floors and surfaces. An overflow message e.g. at the pool edge, or always where a fill level and not soil moisture is involved, should still be detected with a mini float switch.

Memory function overflow message

It is possible to save the overflow message via a jumper and to acknowledge it by pressing a key. With the standard setting, the overflow message is automatically deleted again after the water level has fallen below the limit.

Use with non-conductive liquids

By using our mini float switches, you can also use the SHT 5002 water detector with other liquids that are not conductive or have hazardous properties. All mini float switches from Elektrotechnik Schabus can be activated with liquids from 0.7 grams per cm³, which is sufficient for the vast majority of oily media such as salad oil, lubricating oil, diesel etc.. Even for distilled or chemically purified water, only mini-float switches will work.

Water detector

The overflow detector consisting of input S3, the relay K2, the RESET button and the red LED works completely independently of the level controller and can also be used for completely different tasks. While you are controlling the level in your rainwater cistern, the overflow detector could also detect a leakage under your washing machine in parallel and alert you by means of an external signal horn. The only restriction here is the maximum cable length of 50 meters per sensor input, which must be adhered to for functional safety.

LED status and function display

The LED "Level S1-S2" lights up green when the relay K1 is de-energized and the pump is off. If the pump is activated by energizing the relay, this LED flashes green. The LED "Sensor S3" is off when the water detector is in monitoring mode, i.e. no water is at the sensor and relay K2 is energized. If water now comes to the sensor, K2 drops out and the LED flashes red. While water is still present, the relay can be acknowledged with the reset button and is energized, the LED lights up red. Only when the water leaves sensor S3 again, the red LED goes off.

Can I not rather take sensors, because I can simply hang them from the top and do not have to drill the tank?

We can well understand that you do not want to drill your tank to fix the mounting brackets for the mini float switches. Sometimes this is not possible at all, e.g. for enameled tanks for livestock watering in agriculture. This is exactly what we have designed our suspended float switch for. A flanged-on weight always pulls the suspended float switch downwards, so that it cannot float up and prevent the float from being triggered, even when the water is rising slowly. The enclosed PG screw connection also allows the height of the switch contact to be continuously adjusted at any time.

Possible applications

• Level control e.g. for cisterns (2-point controller)
• adjustable relay e.g. for pump control (empty or fill tank)
• Combined with mini float switches also suitable for other liquids (e.g. heating oil, diesel, vegetable oil, lubricating oils, distilled water etc.)

Performance features

• Own relay for overflow message
• Overflow message with memory function
• Housing for 35 mm standard top-hat rail system (DIN EN 5002)

Technical data

WEEE NO.: EN91394868