Raritan Engineering your marine water heaters experts would like to share with you this week some great information regarding the ease of bilge pump installation.
The best bilge pump in the world won’t keep your boat dry if it’s not properly installed and maintained. While bilge pump installations are fairly straightforward—and definitely within the scope of DIY projects—there are several factors to consider (capacity, wire size, hose diameter, fuse size) before you begin, and there are some good rules of thumb to follow.
CHOOSING AN ELECTRIC PUMP
The first step is selecting the right bilge pump(s) for the job. We recommend installing two electric centrifugal pumps (preferably one with automatic water level sensor): a smaller pump mounted at the belly of the bilge to handle the incidental bilge water (rain, stuffing box drips, etc.) using minimum power and another pump mounted a few inches higher to handle bigger jobs.
• Capacity: For most mid-sized boats (30-35 feet in length), we’d recommend a 1,000-1,500 gallon-per-hour (GPH) pump for the primary and one with a capacity of about 2,000 GPH for the backup.
When comparing output specs on multiple pumps, be sure the rating criteria are the same. New standards set by the American Boat and Yacht Council (ABYC) require that compliant makers rate pump capacities so that they reflect real-world usage. The ABYC stipulates that pumps be rated with a head height (also called vertical lift) of 1 meter and a hose length of 3 meters, and with a head height of 2 meters and hose length of 6 meters. Head height is the vertical height of the hose outlet above the pump outlet.
• Key features: An automatic pump will rely on a water-level sensor such as a float switch to activate the pump. This can be a separate unit or one that is integral to the pump. This sensor should resist fouling and be easy to test for proper operation.
The illustration above shows one recommended setup for automatic bilge pump installation.
• Location: According to the ABYC, the pump inlet must be positioned so that bilge water can be removed when the boat is in a static position and when it is at maximum heel (ABYC H-22). The mounting location also should make it easy to service the pumps and to clean them, particularly their strainers.
When installing two electric pumps, the lower-capacity pump should have a built-in float switch, be mounted at the lowest point of the bilge, and be wired straight to the battery through a fuse. The higher-capacity pump is installed a few inches higher, but not directly above the smaller pump.
• Plumbing: When plumbing an electric bilge pump, be sure the setup is designed to reduce head pressure as much as possible to maximize discharge capacity: use smooth hose sized to meet maker recommendations; keep hose runs as short as possible; and try to avoid bends, turns, and elbow fittings in the run.
We Continue Talking About Easy Bilge Pump Maintenance
Your marine water heaters professionals talk about how the discharge line should rise steadily to the through-hull or loop. If there are any low spots in the run, water will pool there once the pump cycles off. This can create an airlock when the pump is activated again, and the pump likely will stall.
• Wiring: Use correct size wire and fuses: The proper wire size reduces voltage drop and properly fused wiring reduces risk of a locked rotor (a motor that’s trying to turn, but can’t) causing an overcurrent situation and potential fire hazard.
Consult the American Wire Gauge 3% voltage drop table (www.marinco.com/page/three-percent-voltage) to be sure you’re using large enough wire.
For the fuse size, simply go by the pump maker’s recommendation, and you should be set. The fuse, per ABYC standards, should be installed within 7 inches of the power source.
• Accessories: A few accessories to consider adding to the bilge pump system include a visual/audible bilge alarm, bilge switch, and a cycle counter. ABYC standards require an alarm on boats with enclosed berths.
Automatic pumps should always be fitted with a readily accessible and clearly marked manual switch so that even if the owner isn’t around, anyone (crew, marina neighbors, or passersby) can locate and activate the switch when the need arises.
If the larger-capacity pump has a float switch, we highly recommend connecting it to a bilge alarm (and alarm cut-off switch). That way, hopefully, the horn will get someone’s attention before the constant cycling of the pump drains your batteries.
Two good references on bilge pumps and installing them are “This Old Boat” by Don Casey and Nigel Calder’s “Boatowner’s Mechanical and Electrical Manual.”
Regular and frequent inspections of your bilge pumps are a must and should be included in the vessel’s overall preventative maintenance program. This helps you know when to replace worn or damaged components (bad float switches, deteriorated hoses) before they fail.
Keeping your bilge clean can be a hassle, but it doesn’t compare to the headache of a locked rotor or an impotent bilge pump in an emergency.
So keep in mind these pointers when installing and maintaining your bilge pump. 1) The pump inlet must be positioned so that bilge water can be removed when the boat is in a static position; 2) when plumbing an electric bilge pump, be sure the setup is designed to reduce head pressure as much as possible to maximize discharge capacity; and 3) This helps you know when to replace worn or damaged components (bad float switches, deteriorated hoses) before they fail.
Solar and battery technology power a novel hurricane resistant floating electric house boat
Arkup, the “avant-garde life on water” company, has designed a new luxury home that integrates solar on the roof and a newly approved lithium ion marine battery system. The main selling features are that it can rise with sea levels via jacks, withstand extreme weather, move as a regular electric propelled boat, and provide it’s own water plus – of course – electricity.
There are no specifications on the solar panels used – merely multiple notations that 30kW of panels can fit on the roof in 2,300 sq feet.
The systems are liquid or air cooled lithium ion battery kits. The individual battery packs are 5.7kW each and individual stacks go up to 137kWh. No where on the Arkup website it specific the exact number of units, however, they clearly state it is ‘customizable’ – so expect that the only limitation to stored power will be related to space.
The Orca system was recently approved by DNV GL – global ocean classification body – as being safe for maritime usage.
The Arkup is powered by an electric propulsion system – adding to Electrek’s electric boat collection. The system can move at up to 7 knots per hour with a range of 300 nautical miles. With its solar propulsion system – it could probably run indefinitely.
Two points from Arkup’s promotional material gives a feel for the market, in addition to luxury, that they’re aiming for:
Sustainable: Environmentally friendly, powered by solar energy, no fuel, zero emission, equipped with waste management, rainwater harvesting and purification systems, our living yachts are totally off-the-grid.
Resilient: Made for all environments and designed to withstand category 4 hurricane winds, our livable yachts are equipped with a hydraulic self-elevating system to prevent from sea sickness and flooding.
Click here and see how we here at Raritan Engineering always take care of your marine sanitation supply needs.