Hanla FMS-2HS-WS-T Horizontal Float Level Switch SPDT 16A 250VAC

The Hanla FMS-2HS-WS-T is a side-mounted horizontal float level switch engineered for high-reliability liquid alarm and pump sequencing applications. Built around a glandless magnetic coupling architecture, the process wetted end remains completely isolated from the electrical switch compartment via a solid non-magnetic partition wall. This eliminates mechanical seal failures, gland packing degradation, and liquid ingress into the switch terminal chamber under high static pressures.

The unit features a low-profile cranked “S-shape” float arm (HS designator) developed specifically for lowest-sensing level detection in tight sump geometries, bottom bilges, and service tank wells. Equipped with a heavy-duty single-pole double-throw (SPDT) microswitch rated up to 16A resistive / inductive handling, an integrated external manual test lever (-T), and an IP56 weather-proof cast aluminum-bronze / marine-alloy housing (-WS), this instrument provides dependable fail-safe status signalling under continuous vibration and rough sea states.

Model Details:

• Manufacturer Part Number (MPN): FMS-2HS-WS-T
• Series: FMS Horizontal Float Switch Series
• Operating Principle: Repelling/Attracting Dual-Magnet Microswitch Actuation
• Condition: New

Technical Specifications

Features

1. Glandless Magnetic Decoupling: Fluid containment is 100% positive; no dynamic packing seals, O-rings, or bellows separate the tank pressure from the microswitch assembly.
2. High-Capacity 16A SPDT Microswitch: High-load dry contact rated up to 16A, 250VAC / 30VDC, capable of piloting high-power marine contactors, alarms, and engine automation inputs without auxiliary interposing relays.
3. Manual Operational Test Mechanism (-T): External test lever allows engineers to mechanically actuate the internal switch from outside the tank during periodic survey checks without emptying fluid or unbolting flanges.
4. Cranked ‘S-Shape’ Float Geometry (HS): Optimized for low-clearance suction points and bottom bilge sumps, triggering level alarms closer to tank floors than standard straight-arm units.
5. Argon-Shielded Welded SUS316/304 Construction: Hermetically sealed float bulb resists pitting from high-sulfur heavy fuel oil, acidic bilge waste, and marine salt atmospheres up to 10 kg/cm² (10 bar).

Equipment Compatibility

• Marine Automation & Alarm Monitoring Systems (AMS / ICMS): Kongsberg K-Chief 600 / K-Safe, Valmarine (Wärtsilä) NACOS Platinum, ABB Ability System 800xA Marine, Praxis Mega-Guard Automation, Siemens SISHIP Imac.
• Engine Room Auxiliaries & Separator Skids: Alfa Laval S/P Flex Oil Separator Modules, GEA Westfalia OSD/OSB Purifiers, RWO Bilge Water Separators, DVZ Oil-Water Separators.
• Boiler & Tank Level Control Panels: KangRim Boiler Feedwater Systems, Miura Marine Steam Generators, Aalborg Mission Bilge & Hotwell automation.

Frequently Asked Questions

What is the primary difference between Hanla FMS-2H and FMS-2HS?

The standard FMS-2H utilizes a straight float arm, whereas the FMS-2HS features a cranked “S-shaped” bent arm design. The S-shape arm lowers the fulcrum point relative to the flange center line, allowing it to detect minimum liquid levels much closer to the tank floor or sump base.

Can the switch contact action be changed from normally open (NO) to normally closed (NC)?

Yes. The internal microswitch is a 1x Form C SPDT mechanism. If you require normally closed operation on a high level, wire your control loop across Terminal 1 (COM) and Terminal 2 (NC). For normally open operation on high level, land your conductors on Terminal 1 (COM) and Terminal 3 (NO).

What does the -T option in the model code stand for?

The -T designation indicates an external manual test device. This mechanical lever allows crew members or classification inspectors to manually swing the float mechanism externally to confirm signal transmission and alarm functionality without draining or filling the tank.

Does the switch require regular lubrication or gland repacking?

No. Because the FMS-2HS uses non-contact magnetic coupling, the switch chamber is completely dry and hermetically isolated from tank fluids. There are no seals, packings, or shaft glands to grease or adjust.

Can this level switch handle heavy residual fuels and high temperatures?

Yes. Standard models handle process media up to 120°C, and high-temperature configurations handle up to 180°C at 10 kg/cm² working pressure. The standard 0.75 minimum specific gravity float accommodates high-viscosity heavy fuel oil (HFO) without sinking.