Rosemount 2120 Alarm Switch
Rosemount 2120 is a reliable high level alarm switch for hydrocarbon storage tanks. It detects if the liquid level is high, and sends an alarm signal to shut any feed line valves or pumps to prevent tank overfilling and subsequent spillage.
The Rosemount Extended length 2120 is fitted to a nozzle at the tank roof, either directly or by use of an adjustable clamp gland. This tuning fork style switch is designed to vibrate the forks at their natural frequency. Should the liquid level rise to the high level height, the forks become immersed in the liquid and the frequency of vibration changes. The built-in control electronics detects this change and indicates an alarm condition by switching the output.
Rosemount 2120 can be set to switch either if the forks get wet or dry.
See the Rosemount 2120 web page or Product Data Sheet (00813-0100-4030) for more information.
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- Reliable high level alarm switch for storage tanks
- Prevent tank overfill and spillage
- Self-checking tuning fork operation principle
- ATEX, CSA, and UL certifications
- Dry to wet, and wet to dry switch options
Functions to verify the switch is working correctly
- Status indicating LED
- Magnetic Test Point to simulate an alarm situation
Principle:
Fast-drip-off vibrating fork.
Fork Length:
0.05 to 3 m (2 to 118 in.) .
Special Features:
Mode switch: Rosemount 2120 can be set to switch if the forks get either wet (typically high alarm) or dry (typically low alarm).
Adjustable time delay: The time delay is selectable (0.3, 1, 3, 10 or 30 s from dry to wet / wet to dry).
Heartbeat LED: The status indicating LED gives constant indication of whether or not the Rosemount 2120 is functioning correctly. The LED is split when the switch is on and it flashes if it is off.
Magnetic Test point: The test point, located on the side of the housing, can be used for alarm simulation.
Housing Material:
Plastic, Aluminum alloy, or 316 SST (stainless steel).
Conduit Entry:
Two cable / conduit entries, M20, 1/2-in. or 3/4-in. NPT.
Terminal Connection:
Wire diameter max. 2.5 mm2 (0.1 in2). National regulations.
Protection:
Rosemount 2120 is polarity insensitive and has over-current, short-circuit and load-missing protection.
• Ingress protection: IP 66/67 or Type 4X.
• Surge protection according to IEC61326.
Process Connection:
Threaded:
• 3/4-in. BSP or NPT
•1-in. BSP or NPT
Flanges:
• ANSI, 1.5-4 in. 150-600 lb
• DIN (EN), DN 40-100, PN 10/16-100
Wetted Material:
316L SST (EN 1.4404) or Hastelloy C.
Maximum Process Pressure:
-0.25 to 100 barg (-3.62 to 1450 psig), depending on process temperature.
Note: If the Rosemount 2120 switch is used with a clamp gland, the max. operating pressure is limited to 1.3 barg (18.85 psig).
Maximum Process Temperature:
-140 to 150 °C (-140 to 302 °F), depending on the ambient temperature.
Liquid Density Range:
Minimum 600 kg/m3 (37.5 lb/ft3).
Liquid Viscosity Range:
0.2 to 10,000 cP (centiPose).
Hysteresis (water):
± 1 mm (± 0.039 in.) nom.
Switching Point (water):
13 mm (0.5 in.) from tip (vertical) / from edge (horizontal) of fork (this will vary with different liquid densities).
Certification:
• FM Explosion Proof Approval
• FM IS Approval
• CSA Explosion Proof Approval
• CSA IS Approval
• CSA Non-Incendive Approval
• ATEX Flameproof Approval
• ATEX IS Approval
• Electro Magnetic Compatibility (EMC) Directive: EN61326 Emissions to Class B.
• Vibration Resistance: EN60721 level 3M6/4M6.
• Overfill Protection: Approved by DIBt/WHG.
• SIL Declaration of Conformity: SIL 2, IEC 61508 (Type B). |
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