Description
Product Overview
Spirax Sarco LC1350 is an on/off level controller designed for conductive liquids. It governs feed pumps, drain pumps, or solenoid valves on steam boilers, condensate vessels, and storage tanks while monitoring two independent high or low level alarms.
Operating with conductive media having an electrical conductivity as low as 1 µS/cm at 25 °C, LC1350 integrates with the Spirax Sarco LP10-4 four-tip conductivity probe or LP31 probe. It functions reliably under operating conditions in vessels, tanks, or high-output steam boilers operating up to 32 bar at 239 °C. The controller operates on a wide supply voltage range from 99 Vac to 264 Vac at 50/60 Hz with a maximum power draw of 7.5 W. The front interface features a 3-digit LCD screen, animated segment indicators showing level rise or fall, and a five-button keypad.
Key Features
- Dual configurable alarm channels (AL1 and AL2) independently selectable as oFF, Hi, or Lo alarm modes.
- On/off pump control configurable for filling vessels (pumping in) or emptying vessels (pumping out).
- Wide-range universal power supply operating from 99 Vac to 264 Vac at 50/60 Hz without transformer taps.
- Minimum switching conductivity threshold of 1 µS/cm at 25 °C (K = 0.22, 220 kΩ) with ac-pulsed drive.
- Adjustable input damping filter with selectable delays of 0, 2, 4, 8, or 16 seconds, plus fixed 2-second wet-to-dry dominant filter.
- Built-in interactive safety logic (Int) ensuring pump engagement if a low alarm condition is triggered under failure.
- Tamper prevention via fixed three-digit passcode (745) protecting settings stored in internal non-volatile flash memory without batteries.
- Infrared optical port (IrDA, 38,400 baud) for parameter transmission to adjacent controllers as an IR slave unit.
- Front panel rated to IP65 and NEMA Type 4 (hose-down) for industrial enclosure installations.
- Certified compliance with EN 61010-1:2010 safety standards and Vd TÜV Water Level 100 (07.2006) type testing.
Technical Specifications
| Parameter | Specification |
|---|---|
| Mains supply voltage | 99 Vac to 264 Vac at 50/60 Hz |
| Maximum power consumption | 7.5 W |
| Operating ambient temperature | 0 °C to 55 °C (32 °F to 131 °F) |
| Storage environmental limits | 0 °C to 65 °C (32 °F to 149 °F), 10% to 90% RH (non-condensing) |
| Ambient relative humidity | 80% RH up to 31 °C, decreasing linearly to 50% RH at 40 °C |
| Maximum installation altitude | 2,000 m (6,562 ft) above sea level |
| Overvoltage category | Category III |
| Pollution degree | Degree 2 (as supplied), Degree 3 (installed in enclosure) |
| Enclosure protection rating | IP65 and NEMA Type 4 hose-down (front panel only) |
| Enclosure construction | Polycarbonate housing with silicone rubber front keypad (60 Shore) |
| Controller weight | 430 g |
| Conductivity probe input | 1 µS/cm at 25 °C, K = 0.22 (220 kΩ), ac-pulsed excitation |
| Probe cable requirement | 5-core screened high-temperature cable, 1.0 to 1.5 mm² (18 to 16 AWG) |
| Maximum probe cable run | 100 m (328 ft) |
| Output relay configuration | 2 x single pole changeover (SPCO) relays |
| Maximum relay contact voltage | 250 Vac |
| Relay contact ratings | 3 A resistive @ 250 Vac; 1 A inductive @ 250 Vac; 1/4 HP @ 250 Vac; 1/10 HP @ 120 Vac; C300 pilot duty (2.5 A) |
| Relay operating life | 3 x 10⁵ electrical cycles; 30 x 10⁶ mechanical cycles |
| Infrared communications | IrDA physical layer, 38,400 baud, 10 cm range, 15° cone angle, Class 1 exempt |
| Electrical terminals | Rising clamp plug-in blocks with screws, 0.2 to 2.5 mm² (24 to 12 AWG), 5–6 mm strip |
| Panel mounting screw torque | 1.0 to 1.2 Nm |
Applications
- On/off feedwater level control and high/low alarm monitoring on steam boilers operating up to 32 bar at 239 °C (note that steam boilers require two independent low water limiters; LC1350 is not self-monitoring).
- Boiler feedtank inventory management using pump-in filling sequences.
- Condensate receiver tank evacuation using pump-out drainage control.
- External level sensing chambers connected to pressurized boilers where internal top mounting is impractical.
Mechanical Installation & Mounting
Spirax Sarco LC1350 must be installed in a vertical orientation inside an industrial control panel or fireproof enclosure providing a minimum rating of IP54 or NEMA Type 3, 3S, 4, 4X, 6, 6P, or 13. A minimum thermal clearance gap of 15 mm must be maintained between adjacent units for heat dissipation.
The unit accommodates three mounting configurations:
- 35 mm DIN rail: Attach using the supplied spring clip and screws, selecting between two vertical positions on the rear case.
- Chassis plate: Secure using two screws, washers, and nuts through the upper and lower case slots.
- Panel cutout: Insert from behind the panel (minimum 1 mm panel thickness when using the supplied bezel) and fix using two M4 x 25 mm screws and fibre washers into the integral M4 x 0.7 threaded inserts. Tighten screws to 1.0–1.2 Nm. Screws exceeding 25 mm length must not be used to prevent electrical shock.
Electrical Connections & Probe Wiring
All electrical wiring must comply with IEC 60364 and local standards. A dedicated disconnecting switch or circuit breaker complying with IEC 60947-1 and IEC 60947-3 must be positioned in close proximity to the unit. Phase conductors must include overcurrent protection rated at 3 A, and relay contact circuits must incorporate 3 A quick-blow fuses. Relay contacts must be wired to the same electrical phase as the mains supply.
Signal circuits connect to conductivity probes using 5-core screened high-temperature cable up to 100 m in length. The cable shield must be grounded at one end only to avoid ground current loops. Terminal 55 is an internal functional earth connected to the probe body via its NPT or BSP mounting thread; it must not be cross-connected to safety earth or other grounding points. Resistance between the probe body and boiler shell must remain below 1 ohm. An external momentary test switch may be wired across terminals to verify alarm trip circuits without draining boiler water.