This product is the same as the Water Witch 257 Dual System Bilge Pump Switch, but includes an Alarm Buzzer for the second circuit so you don't have to source your own.
The Dual System 257 from Water Witch offers boat owners and manufacturers two systems in one product —
1) Primary protection, to activate a bilge pump when it senses the presence of water.
2) A secondary system to activate an alarm or a backup bilge pump in case of primary bilge pump failure.
The 257’s monitoring system is constantly on guard and will activate the primary bilge pump when it detects water for 8 continuous seconds.
The 257’s secondary circuit will activate only when high water levels are detected for 2 continuous minutes - indicating that the primary bilge pump has failed or is having difficulty emptying the bilge.
The monitoring and secondary systems work hand-in-hand to provide previously unavailable protection in one electronic control. The 257 can be connected to any auxiliary system such as a second bilge pump, audio alarm or visual alarm.
For your convenience, this model 257B includes an alarm buzzer for wiring to the second circuit.
The 257, like all Water Witch products, meets or exceeds the Canadian & U.S. Coast Guard standards and comes with an unmatched 7 year limited warranty.
Other 257 benefits include:
• Works with oily bilge
• Will not pump pure fuel or oil (if there is a major fuel tank breach)
• No electrolysis
• No moving parts
• No pump stutter or short cycling from boat action
• Unmatched 7 year warranty
• Power Required: 12V DC
• Max. Main Load: 15 Amps @ 12 volts
• Max. Aux. Load 10 Amps @ 12 volts (Note that this load is smaller than the primary load.)
• Auxiliary System Activation - after 2 minutes
• Max. Total Load: 20 Amps @ 12 volts (Note that after 2 minutes, both systems will be active.)
• Power used at rest: 0.004 Amps
• Dimensions: 2-1/8"W x 3-1/8"H x 1-5/8"D