Water Powered Back Up Pump with Alarm. 3/4 NPT Water Inlet Connection. Accepts 20PSI up to 100PSI inlet supply pressure SJ10A Water Powered Back Up Pump with indoor 115v alarm with 9v battery back-up. Compact probe mounted sensor, auxiliary contacts with visual and audio alarm. (Model SJ10) is a water powered back-up sump pump that will protect your basement in the case of a power outage. This unique product is powered by your municipal water supply and requires no electricity to operate! With a compact high efficiency design, The SumpJet. Removes 2 gallons of sump water per 1 gallon used. The SJ10 pumping performance varies with inlet water source pressure and pumping head. See complete specifications and performance chart for expected flow rates. The SJ10 requires an uninterrupted water source to operate. If you have a well pump, the SJ10 will not operate during power outages. Download the Installation Manual. Download the Installation Manual – Alarm. Download the Engineering Specifications.