Different Wire Sizes In Bilge Pump Circuit

[cal40john]

Originally Posted by mikefossl

Really? Reference please.

Lot to wade through, do a find on 16 and you'll come across both AC and DC sections requiring 16 gage, with (exceptions) by ABYC standards.

http://www.cruisersforum.com/forums/...ical-1471.html

[MarkSF]

To sum up sailboat wiring :

The wiring should be rated for more than the current used by the device. There's a derating for wiring going through engine compartments.

The wiring should be rated for less than a 10% drop.

The breaker should be rated for a bit more than the current used by the device.

The breaker should be rated for less than the current the wire can handle.

The wiring should be at least 16 gauge, regardless.

[impi]

We have two bilge pumps per hull and then two roaming bilge pumps. The roaming DC bilge pumps run on a length of thick gauge wire ... We have the pool type inter-locking twist pipes (each about 1 m length) which we keep onboard.
We have a serious 12v output terminal (positive and negative) at the rear of the boat which is in a high dry area ... Clamp on crocodile clamps and throw the pump/s where needed the most ... Pipe out of nearest hatch and presto ...
Works for us ...

[downunder]

Off topic but anyone with any experience of these engine driven bilge pumps.

Fast Flow Emergency Bilge Pump

[mikefossl]

Originally Posted by cal40john

Lot to wade through, do a find on 16 and you'll come across both AC and DC sections requiring 16 gage, with (exceptions) by ABYC standards.

I'm thinking that the 18 gauge wire on the float switch would be covered by one of the exceptions (as long as the 'pigtail' is less then 30 inches). In any case, the exceptions do indicate that yes there is a place for 18 gauge wire on a boat (my instrument panel is full of them) .

[mikefossl]

Originally Posted by downunder

Off topic but anyone with any experience of these engine driven bilge pumps.

Fast Flow Emergency Bilge Pump

It's on my Amazon wish list if anyone wants to oblige.

[GordMay]

Originally Posted by mikefossl

I'm thinking that the 18 gauge wire on the float switch would be covered by one of the exceptions (as long as the 'pigtail' is less then 30 inches). In any case, the exceptions do indicate that yes there is a place for 18 gauge wire on a boat (my instrument panel is full of them) .

Excerpted from ABYC E-11:

11.14.1.2 Conductors shall be at least 16 AWG.
EXCEPTIONS:
1. 18 AWG conductors may be used if included with other conductors in a sheath and do not extend more than 30 inches (760mm) outside the sheath.
2. 18 AWG conductors may be used as internal wiring on panelboards.
3. Conductors that are totally inside an equipment enclosure.
4. Conductors on circuits of less than 50 volts having a current flow of less than one amp in communication systems, electronic navigation equipment and electronic circuits.
5. Pigtails less than seven inches (178 mm) used as wiring on panelboards.

11.14.2.6 Voltage Drop - Conductors used for panelboard or switchboard main feeders, bilge blowers, electronic equipment, navigation lights, and other circuits where voltage drop must be kept to a minimum, shall be sized for a voltage drop not to exceed three percent. Conductors used for lighting, other than navigation lights, and other circuits where voltage drop is not critical, shall be sized for a voltage drop not to exceed 10 percent.

2. If the ampacity as specified in E- 11.14.2.5 exceeds the ampacities in TABLE IX and TABLE X, the conductor size necessary to keep voltage drop below the maximum permitted level may be calculated by means of the following formula:
CM = (K x I x L) ÷ E
Where:
CM = Circular mil area of conductor.
K = 10.75 (constant representing the resistivity of copper)
I = Load current in amperes
L = Length of conductor from the positive power source connection to the electrical device and back to the negative power source connection, measured in feet.
E = Maximum allowable voltage drop at load in volts (e.g., for a three percent voltage drop at nominal 12V, E= 0.03 x 12 = 0.36; for a 10 percent voltage drop at nominal 12V, E = 1.2).

See also ➥ http://www.cruisersforum.com/forums/...boats-372.html

[Rick01541]

Originally Posted by downunder

Off topic but anyone with any experience of these engine driven bilge pumps.

Fast Flow Emergency Bilge Pump

An alternative to adding a pump to the prop shaft would be to install a valve on the raw water intake and run the hose to the bilge. Besides being an emergency bilge pump it is great for winterizing the engine. Just pour antifreeze into the bilge and flip the valve.