KROHNE SWSILBT01 User Manual

Data sheet

Liquid Level Switch Type LLS 4000/4000U

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 G3/4" 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.

Features

• 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

• 2 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

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.

• Approvals: CE, PED, EMC, RED, ROHS, SIL2, FCC, ( EAC, IC pending)

• Conforms to: Telecommunications Directive RED 2014/53/EU. Low voltage directive 2014/35/EU. EMC directive 2014/30/EU.

ROHS 2011/65/EU

AI323832972563en-000101 | 1

Contents

Data sheet | Liquid Level Switch, type LLS 4000/4000U

Features .............................................................................. 1

uct concept/applications ........................................................... 3

Prod

Connection types ...................................................................... 4

Measuring principle..................................................................... 4

ctrical installation/connection......................................................... 5

LED light indicators .................................................................... 5

Configurable parameters .... .. ..... .. ..... ... ..

Ordering ................

Dimensions and weights .................................................................7

Maintenance/service & calibration precautions............... ............................. 8

Bluetooth communication .............................................................. 8

Bluetooth configuration ................................................................ 9

Technical data .................................

Safety/ Approvals .......................................................................11

.. ... ..... ... .. .. ... ..... .. ... . 5

..... ... .... .. .... ... ..... ... .... ... ..... .. ..... .. ... 7

........................................10

2 | AI323832972563en-000101

Product concept/

Data sheet | Liquid Level Switch, type LLS 4000/4000U

applications

To control if a liquid level is within predened 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.

SFA

+DSV

FIA

SNV

SCA-X

SVA

SNV

260A

SNV

SVA

BSV

LLG

LLS 4000

SVA

AKS 4100

LLG

SCA-X

SNV

SVA

260A

EKE

347

ICF 25-6-5A

SVA

SNV

SVA

BSV

SNV

SVA

QDV

FIA

SNV

The LLS can be used wherever liquid levels of ammonia and certain H(C)FC refrigerants must be controlled.

Upper LLS 4000/U

Lower LLS 4000/U

The LLS comes in 2 versions:

- A standard version, which is applicable for most refrigeration or processing plants, and is fully configurable regarding type of liquid and relay setting.

- A SIL2 version applicable for SIL compliant process plants. This version is non-configurable regarding relay setting (see section: Configurable parameters) and is intended specific as the upper level switch.

Liq. Level

AI323832972563en-000101 | 3

Data sheet | Liquid Level Switch, type LLS 4000/4000U

Connection types

Beside the 2 versions the LLS also comes with 2 different thread types , LLS 4000 and LLS 4000U. They are identical except for the connector thread for installation to the system. The LLS

4000 is provided with G¾" thread, while the LLS 4000U is provided with NPT ¾" thread.

LLS 4000

LLS 4000U

G ¾”

NPT ¾”

For connection to the actual part of the system appropriate weld connectors are needed. NPT connectors are widespread available, while Danfoss offers weld connectors for G3/4" thread as accessory. Please note geometric restrictions below.

Weld connector

max

45 mm

1.8 in

min

25 mm

1 in

Measuring principle

The measurement principle of the LLS is based on reflectometry with a 4.9 GHz to 6.2 GHz linear sweep (Microwave switch technology).

The reflected signal is characterized by a resonance frequency. The resonance frequency in air is taken as a reference (fref). When the

sensing element is in contact with the liquid, the resonance frequency is shifting to a lower frequency. This is due to the change of the dielectric constant of the medium.

4.9 GHz 6,2GHz

with

liquid

The point level switch monitors the resonance frequency and indicates whether the sensing

element is surrounded by liquid or gas. The figure below shows the reference frequency with air (dielectric constant εr=1) in front of the sensing element and with a liquid dielectric constant εr> 1.35.

∆f ~ ε

without

liquid

ref

AI323832972563en-000101 | 4

+ 7 hidden pages