Spirax Sarco LCS3050 single-probe low-level switch is used with an LP40 level probe to limit the water level in steam boilers and (pressurized) hot water installations. When the level falls below the preset minimum, the level switch shuts off the heating. This single-probe level switch is designed for connection to one level probe. When the actual level falls below the low-level setpoint, the level probe is exposed and the level switch triggers a low-level alarm. The trigger point is determined by the length of the probe rod on LP40 level probe. After the power-off delay has ended, the two output contacts of the level switch interrupt the heating safety circuit. The heating shutoff function is interlocked with the external safety circuit and can only be deactivated when the level probe is immersed in water again. The output signal connected to an external alarm device is also switched off instantaneously.

If the level probe and/or electrical connection fails, an alarm is also generated. A self-test routine monitors the safety functions. In the event of a fault, the safety circuit opens immediately and stops the heating. Alarm and error information is displayed by LEDs, and the output signal is activated immediately without delay. Users can press the test button to simulate an alarm.

Directives and Standards

• Under the European Pressure Equipment Directive (PED) 2014/68/EU, the LCS3050 level switch used in combination with LP40 level probe has received EU type approval in accordance with EN 12952/EN 12953.

• Functional safety complies with IEC 61508. The LP40 + LCS3050 equipment combination corresponds to a Type B subsystem with Safety Integrity Level (SIL) 3.

• Type approval has been granted according to VdTÜV Bulletin “Water Level 100”.

• Complies with the requirements of Low Voltage Directive 2014/35/EU and EMC Directive 2014/30/EU.

• In accordance with European Directive 2014/34/EU, it must not be used in areas where explosion protection is required.

Technical Specifications

• Power supply: 24 Vdc +/- 20%

• Fuse: External 0.5 A (semi-time-delay)

• Power consumption: 7 W

• Electrical connection to level probe: Input for 1 LP40 level probe, 4-core shielded cable

• Response sensitivity: Water conductivity at 25℃ > 10 …< 10000 μS/cm

• Outputs: 2 potential-free dry contacts, 6 A 250 Vac/30 Vdc cos f = 1; response delay time 3 seconds; 1 external potential-free output, 24 Vdc, maximum 100 mA (semiconductor output)

• Indicators and controls: 1 red LED and 1 green LED for operating status and alarm indication; 3 red LEDs for diagnostics

• Enclosure material: Black polycarbonate base; gray polycarbonate front panel

• Electrical safety: Pollution degree 2, overvoltage category III (EN 61010-01); enclosure protection rating IP 40 (EN 60529); terminal block protection rating IP 20 (EN 60529)

• Weight: Approximately 0.5 kg

• Ambient temperature: 0 55℃ when energized; -10 55℃ during operation; transport temperature -20 +80℃ (<100 hours), defrosting time of 24 hours before commissioning a de-energized device; storage temperature -20 +70℃, defrosting time of 24 hours before commissioning a de-energized device

• Relative humidity: Maximum 95%, non-condensing

• Altitude: Up to 2000 m

Wiring

The terminal block is removable, and the enclosure is mounted on a TH 35 support rail (EN 60715). Wiring specifications are as follows:

• Maximum conductor size: 1 x 4.0 mm² (per solid wire), or 1 x 2.5 mm² (per stranded wire with ferrule complying with DIN 46228), or 2 x 1.4 mm² (per stranded wire with ferrules complying with DIN 46228)

Description

Single-probe low-level switch with 2 safety-circuit potential-free dry contacts, 1 external alarm output signal, 24 Vdc power supply, and 7 W power consumption.

Ordering Example

1 Spirax Sarco LCS3050 level switch for a single low-level probe.