Danfoss LLS 4000 Liquid level switch

LLS 4000
Danfoss LLS 4000 Liquid level switch
LLS 4000

The LLS 4000/4000U liquid level switch is designed to detect the state (gas or liquid) of the refrigerant in front of the sensing head, while installed in a wide range of refrigeration applications.

The LLS level switch comes in 2 variants, LLS 4000 and LLS 4000U. They are identical except for the connector thread interface to the system. The LLS 4000 is provided with G 3/4” thread, while the LLS 4000U is provided with NPT 3/4” thread.

The LLS 4000/4000U liquid level switch is based on the proven reflectometry measuring technology (microwave level measurement) adapted specifically for the new LLS 4000/4000U switch.

LLS 4000/4000U liquid level switches can be used to control the liquid level of many different refrigerants in vessels, accumulators, receivers, standpipes, etc.

The switches are normally installed in a pair of two, controlling the upper liquid level and the lower liquid level.

The level switch includes a relay that switches by change in refrigerant state. The on site configuration of the LLS allows the normally open/closed relay setting depending on the desired correlation.

For SIL applications a SIL2 version is available with blocked configuration (not configurable).

All configuration and readings from the LLS switch are performed through Bluetooth and a downloadable special Danfoss app.



  • Plug and play liquid level switch
  • Easy installation and minimum or no need for configuration
  • Convenient communication with all units via Bluetooth and a Danfoss app
  • SIL2 compliant version
  • Two commonly used connection variants
  • Maintenance free
  • Replacement of electronic part without removing mechanical part (no opening to refrigerant)
  • Applicable for ammonia and commonly used H(C)FCs
  • Well proven reflectometry measuring principle
  • Approvals:
    EAC (pending)
    CMIIT/TAC (pending)
  • Conforms to:
    Telecommunications Directive RED 2014/53 EU.
    Low voltage directive 2014/35/EU.
    EMC directive 2014/30/EU.
    ROHS 2011/65/EU


To control if a liquid level is within predefined allowed limits, two LLS 4000 are installed in an upper and a lower limit  position  respectively. By this setup the liquid level is between the two level switches and the lower switch will sense liquid, while the upper will sense gas. In case the liquid level moves outside the limits, one of the switches will sense opposite and switch the built-in relay. This relay switch function should be used for alarm settings. This is made easy when connected to the system PLC.

    Another Article :Erdco Turbo-Flo 20 SeriesUltrasonic Level Meter Honda HD350Jenis Level SensorPressure Level TransmitterMechanical Level Transmitter


Technical Data

Read more:https://inaparts.com/level-measurement/danfoss-lls-4000-liquid-level-switch/

Tinggalkan Balasan

Please log in using one of these methods to post your comment:

Logo WordPress.com

You are commenting using your WordPress.com account. Logout /  Ubah )

Gambar Twitter

You are commenting using your Twitter account. Logout /  Ubah )

Foto Facebook

You are commenting using your Facebook account. Logout /  Ubah )

Connecting to %s