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Indoor Tank Alarm (High Water Alarm) - 30 foot Mercury Float - Battery Backup

SKU: SP-3100-30

Price: $88.99

The SP-3100-30 alarm system is designed to monitor liquid levels in sump basins, holding tanks, lift stations tanks and many other non-potable water and wastewater applications.

The SP-3100-30 is design to sound an audible horn and illuminate a red light to notify of an alarm situation. There is a green line voltage power indicator light to show that the unit is functioning, as well as a silence switch to turn horn off while fixing the alarm (the red alarm light will remain on until the alarm conditions are remedied).

  • Features
  • Red "Alarm On" LED
  • Green "Power On" LED
  • Alarm test and horn silence button with auto reset
  • NEMA 1 Thermoplastic enclosure with external mounting feet , for indoor usage.
  • Alarm operates on 12 VDC, reducing the possibility of accidental electric shock.
  • Auxiliary contacts with common, normally open and normally closed terminals are available behind a panel, on the lower right side, held in place by two #1 Phillips head screws. The barrier terminal screws are Phillips/Standard slot combo head type.
  • Complete alarm includes a small (Mercury) float switch with mounting strap and 30 foot cord.
  • Mercury Float Switch AS2OY3000

Spec Sheet

Manufacturer: MDI Sewage Products

Weight: 3 lb
Stock Quantity: Made to Order

Delivery: Ships in 5-8 Business Days


This Product Contains Mercury. Please Check if your in IMERC compliance

This product contains mercury.
Please click to check if you are in IMERC compliance.

BBLA Indoor Alarm

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Alarm Installation
AS 00
  • Specifications
  • Voltage
    • Primary 120 VAC, 60 Hz
    • Secondary 12 VAC 60 Hz
  • Enclosure NEMA 1 Thermoplastic enclosure with external mounting feet 6" X 3.75" X 2.50"
  • Alarm horn 85 Decibels at 10 feet
  • Power Cord 6 feet 120 VAC (NEMA 5-15P)
  • Battery Backup 9V Battery
  • Auxiliary contacts 120 VAC, 5 AMP MAX. 60 Hz
  • Features
    • Red "Alarm On" LED
    • Green "Power On" LED
    • Alarm test and horn silence button with auto reset
  • Low voltage screw terminals Class 2 Output, 12 VDC, connect ONLY the float switch leads to the Low voltage screw terminals.
    • DO NOT APPLY ELECTRICAL POWER
  • Float Switch (Included)
  • Mercury Float AS2OY3000
  • Cable 30 foot length, 18 Ga. 2 conductor, SJOW chlorinated polyethylene jacket
  • Float 2" Dia X 3"
  • Float Material ABS
  • Switch 5° operating angle, hermetically sealed mercury switch

MDI Inc. Our Company!

See all MDI Sewage Products
Mercury Displacement Industries Incorporated, better known in the industry we serve as MDI, was incorporated in Michigan in 1975. The primary product line is switch gear components including mercury type contactors, tilt switches and liquid level float controls.
Contactors are rated from 30 to 100 Amperes and are commonly used in various heating, lighting, and many other industrial applications including high voltage ultraviolet type loads. The contacts are encased in hermetically sealed stainless steel tubes to provide reliable switching for millions of operations. All basic units are UL, CSA, and CE approved.
The liquid level control floats are manufactured with mechanical or mercury switches. The float material is High Impact Polystyrene for normal alarm, sump pump or water applications, For sewage, 1 or 2 H.P. or high temperature, 86°C (186°F) requirements Acrylonitrile Butadiene Styrene, (ABS) float material is provided.
MDI has 40 to 50 employees and markets products through distributors, representatives or direct to OEM accounts throughout the world.

MDI Quality Policy
It is the policy of MDI to manufacture and market products of excellent quality, durability and reliability. This policy emphasizes the importance of product reputation and customer satisfaction in the success of our business. The MDI Team is committed without exception to the continuous improvement in quality and cost, and to manufacturing productivity and efficiency.

Since 1975
MDI Quality - Durability - Reliability

Call Us Toll Free: (800) 634-4077

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Non-Mercury Alternatives

IMERC State Restrictions'

Due to mercury-added products being banned or phased out in some states, MDI cannot ship Mercury added products (Relays, Switches and Floats) to the following IMERC states:
Connecticut (CT), Minnesota (MN), Maine (ME), Massachusetts (MA), New Hampshire (NH), New York (NY), Rhode Island (RI), or Vermont (VT)

These states belong to the Interstate Mercury Education and Reduction Clearinghouse (IMERC) group, which have these restrictions.

Exemptions are currently being applied for in cases where Mercury Relays and Switches are being used to replace relays and switches in equipment originally manufactured with Mercury Relays and Switches. But, currently, MDI cannot ship into these states.