{"product_id":"rule-37a-super-switch-bilge-pump-float-switch","title":"Rule 37A Super Switch Bilge Pump Float Switch","description":"\u003cp\u003eThe Rule 37A is a mercury-free bilge-pump float switch for automatic pump control on 12V, 24V and 32V DC systems, with a maximum switching capacity of 20A at 12V; 10A at 24V; 6.5A at 32V.\u003c\/p\u003e\u003cp\u003eThe Rule 37A controls a non-automatic bilge pump by closing the electrical circuit as water raises the float and opening the circuit after the water level falls. It uses marine-grade blocked wire and a mercury-free snap-switch design for marine bilge installations.\u003c\/p\u003e\u003ch4\u003eProduct Identification\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Rule\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct name:\u003c\/strong\u003e Rule 37A Super Switch Bilge Pump Float Switch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eModel \/ part number:\u003c\/strong\u003e 37A\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMarine Scene SKU:\u003c\/strong\u003e CW-37A\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct category:\u003c\/strong\u003e Automatic bilge-pump float switch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatible system voltage:\u003c\/strong\u003e 12V, 24V and 32V DC\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaximum switched current:\u003c\/strong\u003e 20A at 12V; 10A at 24V; 6.5A at 32V\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePump ON level:\u003c\/strong\u003e Approx. 51 mm (2 in)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePump OFF level:\u003c\/strong\u003e Approx. 19 mm (3\/4 in)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSwitch mechanism:\u003c\/strong\u003e Mercury-free snap switch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIgnition protection:\u003c\/strong\u003e Yes\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuantity supplied:\u003c\/strong\u003e One float switch\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eWhat Is the Rule 37A Float Switch Used For?\u003c\/h4\u003e\u003cp\u003eThis switch is used to convert a compatible standard bilge pump into an automatically controlled system. It may also be used as the sensing switch in a compatible high-water alarm circuit where the electrical ratings and installation instructions are observed.\u003c\/p\u003e\u003ch4\u003eWhat Is Included?\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eOne Rule 37A float switch\u003c\/li\u003e\n\u003cli\u003eFactory-fitted marine-grade blocked wire\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eWhat Is Not Included?\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eBilge pump\u003c\/li\u003e\n\u003cli\u003ePanel switch\u003c\/li\u003e\n\u003cli\u003eCable extensions and waterproof connectors\u003c\/li\u003e\n\u003cli\u003eIn-line fuse holder and correctly rated fuse\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eWhich Bilge Pumps and Electrical Systems Are Compatible?\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eCompatible with 12V, 24V and 32V DC systems within the stated current limits.\u003c\/li\u003e\n\u003cli\u003eUse with a non-automatic bilge pump whose running and starting current do not exceed the switch rating.\u003c\/li\u003e\n\u003cli\u003eCan be combined with a compatible Rule three-way panel switch for automatic\/off\/manual control.\u003c\/li\u003e\n\u003cli\u003eNot a voltage converter; the pump, switch and panel must all suit the vessel electrical system.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eHow Do I Check the Electrical Rating?\u003c\/h4\u003e\u003cp\u003eThe pump operating and starting current must remain within the published switch rating: 20A at 12V; 10A at 24V; 6.5A at 32V. Match the switch, pump and any panel to the same system voltage: 12V, 24V and 32V DC.\u003c\/p\u003e\u003ch4\u003eAt What Water Level Does the Switch Operate?\u003c\/h4\u003e\u003cp\u003eThe published switching levels are ON at Approx. 51 mm (2 in) and OFF at Approx. 19 mm (3\/4 in). Installation angle, mounting position and unrestricted float movement must be maintained.\u003c\/p\u003e\u003ch4\u003eConstruction and Design\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSwitch mechanism:\u003c\/strong\u003e Mercury-free snap switch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProtective cover:\u003c\/strong\u003e No external impact cover\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBuilt-in test feature:\u003c\/strong\u003e No\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIn-line fuse holder:\u003c\/strong\u003e Not included\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMounting base:\u003c\/strong\u003e Removable, interchangeable mounting base\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWire size and length:\u003c\/strong\u003e 14 AWG marine-grade blocked wire; approx. 712 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIgnition protection:\u003c\/strong\u003e Yes\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eInstallation and Safety\u003c\/h4\u003e\u003cp\u003eMount the switch on a level surface beside the pump, with unrestricted float movement and without contact from hoses, wiring or debris. Position wiring connections above the maximum bilge-water level, fit the pump manufacturer’s specified fuse, and test the switch by lifting the float before leaving the vessel unattended. The fuse protects the circuit and must be selected for the pump; it is not set by the switch maximum-current rating.\u003c\/p\u003e\u003ch4\u003eMaintenance\u003c\/h4\u003e\u003cp\u003eTest the switch through its full movement at regular intervals and keep the bilge area around it clear.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eRemove oil, dirt and debris that could restrict the float.\u003c\/li\u003e\n\u003cli\u003eInspect the hinge, protective cover, wiring and terminals.\u003c\/li\u003e\n\u003cli\u003eConfirm that the pump starts and stops at the expected water levels.\u003c\/li\u003e\n\u003cli\u003eInvestigate repeated fuse failure or intermittent operation before relying on the automatic system.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eAutomatic on\/off control for compatible bilge pumps\u003c\/li\u003e\n\u003cli\u003eMercury-free snap-switch mechanism\u003c\/li\u003e\n\u003cli\u003eMarine-grade blocked wiring\u003c\/li\u003e\n\u003cli\u003eMaximum switching capacity: 20A at 12V; 10A at 24V; 6.5A at 32V\u003c\/li\u003e\n\u003cli\u003eIgnition protected for marine use\u003c\/li\u003e\n\u003cli\u003eLarger float for increased buoyancy\u003c\/li\u003e\n\u003cli\u003eRemovable base for cleaning and servicing\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eFrequently Asked Questions\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eWill this switch work with any bilge pump?\u003c\/strong\u003e\u003cbr\u003eOnly when the pump voltage and current are within the Rule 37A ratings. Check both running current and the manufacturer installation requirements.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eAt what water level does the switch operate?\u003c\/strong\u003e\u003cbr\u003eThe float switches on at approximately 51 mm (2 in) and switches off at approximately 19 mm (3\/4 in). Installation angle and bilge movement can affect actual operation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the maximum amp rating determine the fuse size?\u003c\/strong\u003e\u003cbr\u003eNo. Fit the fuse specified for the bilge pump and cable circuit. The switch rating is the maximum current the switch can control.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes this product include a bilge pump?\u003c\/strong\u003e\u003cbr\u003eNo. This listing is for the float switch only.\u003c\/p\u003e\u003ch4\u003eSpecifications\u003c\/h4\u003e\u003cdiv style=\"width: 100%; overflow-x: auto; -webkit-overflow-scrolling: touch;\"\u003e\n\u003ctable class=\"spec-table\" style=\"width: 100%; border-collapse: collapse; font-family: Roboto, Arial, sans-serif; background: #ffffff; text-align: center;\"\u003e\n\u003cthead\u003e\n\u003ctr style=\"background: #f5f5f5;\"\u003e\n\u003cth style=\"border: 1px solid #ddd; padding: 8px; text-align: center; font-weight: 500;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"border: 1px solid #ddd; padding: 8px; text-align: center; font-weight: 500;\"\u003e37A\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e\u003cstrong\u003eBrand\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003eRule\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e\u003cstrong\u003eProduct category\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003eAutomatic bilge-pump float switch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e\u003cstrong\u003eMarine Scene SKU\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003eCW-37A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e\u003cstrong\u003eCompatible system voltage\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e12V, 24V and 32V DC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e\u003cstrong\u003eMaximum switched current\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e20A at 12V; 10A at 24V; 6.5A at 32V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e\u003cstrong\u003ePump ON level\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003eApprox. 51 mm (2 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e\u003cstrong\u003ePump OFF level\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003eApprox. 19 mm (3\/4 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e\u003cstrong\u003eWire size and length\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e14 AWG marine-grade blocked wire; approx. 712 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e\u003cstrong\u003eSwitch mechanism\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003eMercury-free snap switch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e\u003cstrong\u003eProtective cover\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003eNo external impact cover\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e\u003cstrong\u003eBuilt-in test feature\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003eNo\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e\u003cstrong\u003eIn-line fuse holder\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003eNot included\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e\u003cstrong\u003eMounting base\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003eRemovable, interchangeable mounting base\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e\u003cstrong\u003eApproximate dimensions\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e105 x 40 x 110 mm (L x W x maximum raised height)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e\u003cstrong\u003eIgnition protection\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003e\u003cstrong\u003eHigh-water alarm use\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border: 1px solid #ddd; padding: 8px; text-align: center;\"\u003eCompatible where circuit ratings and installation requirements are met\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e","brand":"Rule","offers":[{"title":"Default Title","offer_id":47309886128405,"sku":"ASAP-504795","price":70.98,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0773\/6151\/2725\/products\/37a.jpg?v=1698135677","url":"https:\/\/marinescene.co.uk\/products\/rule-37a-super-switch-bilge-pump-float-switch","provider":"Marine Scene","version":"1.0","type":"link"}