Bilge Pumps - Overview

1. Description

There are 2 bilge areas maintained by 3 bilge pumps:

• Lazarette

Combined pump / float switch.

• Main Bilge

Below the galley sink, this is the catch-all for any liquid within the boat. This is serviced by 2 pumps:

• Upper High-volume Pump
  • Float switch – set some 30cm above the bilge-bottom
  • Hour counter wired to the Auto wire (assured by a diode).
  • This pump should never operate – all water should be handled by the lower pump. This is a high-volume pump designed to both back up the lower pump and handle large volumes in an emergency.
• Lower Low-volume Pump
  • Float switch set low in the bilge.
  • This pump handles normal small amounts of bilge water.

The switch bank is on a panel by the nav station.
 
1.1. Cable Colour Coding

As there are multiple conductors required to operate these pumps, a colour coding scheme has been adopted. The secondary colour in each case is denoted by heat-shrink insulation / coloured cable ties either over the terminal fitting or at regular intervals along the cable. The primary colour is the colour of the cable itself.

Primary Colour	Secondary Colour	Designation Code
Red	Red	Manual Pump Operation
Red	Green	Auto Pump Operation (controlled by an automatic switch)
Red	Blue	Hour Counter ON/OFF
Black	Black	Negative return

2. Touch Points
This circuit is powered directly from the house battery busbars. Circuit protection is provided by fuses in the pump switches

3. Power Requirements

Section	Component	Circuit Code	Current
Lazarette	Pump	P1	1.5A
Main Bilge	Upper High-Volume Pump Lower Low-Volume Pump	P2 P3	20A 2.5A
Total Overall			24A

4. Parts List

Ref.	Description
S1	Lazarette Bilge-Pump switch unit with 2 settings (Manual / Auto), indicator LEDs and a fuse.
S2	Main Upper / High-volume Bilge-Pump switch unit with 2 settings (Manual / Auto), indicator LEDs and a fuse.
S3	Main Lower / Low-volume Bilge-Pump switch unit with 2 settings (Manual / Auto), indicator LEDs and a fuse.
M1	Hour counter for the Main Upper / High-volume Bilge-Pump.
FS1	Main Upper / High-volume float switch
FS2	Main Lower / Low-volume float switch
D1	Diode to ensure that the hour counter for the Main Upper / High-volume Bilge-Pump only operates in Auto mode
P1	Lazarette Bilge-Pump / Float Switch
P2	Main Upper / High-volume Bilge-Pump
P3	Main Lower / Low-volume Bilge-Pump

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