Spirax Sarco LP30 self-monitoring liquid level sensor is used with Spirax Sarco LC3050 liquid level controller to provide a high-integrity, self-monitoring low-level alarm function for steam boilers. It consists of a sensor body (with removable wire plug) and a separate sensor probe. The sensor probe is threaded into the sensor body and secured with a locknut and pin, with the sensor body forming the earth return circuit. Under normal operating conditions, the sensor probe is immersed and the resistance to earth is low. When the water level falls below the sensor probe, the resistance to earth increases, causing the controller to provide a low-level alarm signal. A comparison probe compensates for any leakage in resistance to earth caused by scale, contaminants, or internal water droplets, ensuring that the correct low-level alarm signal is detected even under demanding conditions.

Features

• High-integrity, self-monitoring low-level alarm sensor

• Suitable for pressures up to 32bar g(239℃)

• Maintenance-free

• Securely fixes the sensor probe

Probe Lengths

500(19.7)mm, 1000(39.4)mm, and 1500(59)mm

Materials

Part No.	Material
1	Sensor body: Austenitic stainless steel BS EN 10088-3(1.4306)
2	Outer layer: Austenitic stainless steel Type 316L
3	Polycarbonate
4	Plug and terminals: Polyamide
5	Silicone rubber
6	Comparison probe: Austenitic stainless steel Type 316L
7	Primary and secondary insulators: PTFE BS 6564 GradeUA Type 1
8	Retaining pin: Austenitic stainless steel Type 302/304
9	Probe: Austenitic stainless steel Type 316L
10	Locknut: Austenitic stainless steel BS 6105 A4 80

Connections

Connection is via a ½” BSP female threaded interface; ½” NPT is also available.

Wiring

Must be connected to Spirax Sarco LC3050 controller. Refer to LP30 low-level alarm wiring diagram for wiring details.

Installation

• This sensor is designed for use with Spirax Sarco LC3050 controller. Steam boilers typically require two sensors and controllers to provide first low-level and second low-level alarms, respectively.

• A protection tube is required when installed in a boiler or a tank subject to severe turbulence.

• Warning: LP30 sensor probe must not contact any part of the boiler. Standard requirements specify a minimum distance of 14mm between the probe and the protection tube. This must be checked when installing the sensor. Spirax Sarco can supply a clearance checking component, part No.4024781.

Maintenance

Although steam boiler water level controls require regular testing, this product requires no special maintenance.

Approximate Weight Including Packaging

Probe Length	Weight(kg(lb))
500mm(19.7”)	0.51(1.1)
1000mm(39.4”)	0.63(1.4)
1500mm(59”)	0.92(2.0)

Ordering Information

Example: 1 - Spirax Sarco LP30 self-monitoring liquid level sensor, LP30 sensor probe 1000mm.