Powerline Model 23-11
120 Amps
Date Code: MAY-22-03
Serial No.: A11040
Purchased: 7/03

Spare alternator

Powerline Model 23-11
120 Amps
Date Code: 60297
Serial No.: A06856

14 pole alternator puts out a 50% duty cycle on the R terminal (white wire) -- 7 pulses per revolution (tach takeoff not used on Willow)

The alternator ratings are based on SAE standards -- 6,000 RPM alternator speed and 78F temperature. The maximum temperature is 300F. The efficiency of a high-output alternator is around 49%. An automotive alternator is only around 30% efficient (Rodney Knelly at Hehr)

Pulley is a Powerline Model No. 8-603, 2.2" diameter. Crank shaft pulley is 4.75" diameter. (2.16 ratio)

The original pulley (8-609) measured at 2.7" x 7/16". The new pulley measures 2.2" x 1/2".

Belt is a Gates Green Stripe (notches on belt), No. 9412 (12.5/13mm x 1050mm) or NAPA 25-10455 (25 9412). On the belt is written 13A1040. The belt lifetime is between 300 and 400 hours. Replace every 300 hours.

To remove the pulley nut, an impact wrench (rented) is magic. The nut is 15/16". Without an impact wrench, use a 5/16" hex key inserted into the center of the shaft to lock it and then use a wrench on the nut. The nut should be tightened to around 50 ft-lbs.

Defender carries parts for Powerline

Recommended alternator filters from Powerline: Electrocube (800-516-1112) G2438 fluorescent light filter on the field, G2418-150 on the power output.

Repair kit 13-113 (list $110). Rebuild the alternator every 3,000 hours. If the boat is left standing in a salty environment, the alternator may not output a voltage. If so, sand the slip rings to get rid of corrosion, sand the brushes, and reassemble. The alternator does not have any type of over-temperature current fold-back internal to it.

Rebuilt old unit that failed after about 2,000 hours. The repair place said that the bearings overheated due to too tight of a belt. They suggested tightening the belt just enough to stop the pulley from being able to turn when gripped with my hand. Then, run the engine until hot and adjust the belt again. The old unit is now a spare onboard.

.alternator performance curve (79445 bytes)

Alternator Filter

Installed a low-pass LC filter from Newmar. Part number 150-A This filter is supposed to remove alternator noise from the radios.

Batteries – 12V



Case Size



Reserve Cap. (min)


Starting Battery   Group 27




House (starboard settee -- 4x 6V) Trojan T-105





Battery cable between house batteries is 2/0 AWG Ancor.

Size Length Width Height Weight* Ah* Stud
Group 24 11" 7" 10" 50 70 3/8"(+) and 5/16"(-)
Group 27 12" 7" 10" 60 90 3/8"(+) and 5/16"(-)
4-D 20" 8" 10" 130 180  
8-D 20" 11" 10" 160 225  
T-105 6V 10" 7" 11" 62 225 5/16"

* Approximate, depending on battery technology, manufacturer, etc.

Reserve Capacity = minutes to drain 25 amps @ 80F to 1.75V/cell (10.5V)

Amp-Hours = number of amps discharged for 20 hours @ 80F to 1.75V/cell (10.5V). To calculate Amp-Hours capacity at a different discharge rate, use

        CR = R * H * (CH / (R * H))P


CR   Amp-Hour capacity at the new discharge rate
H   Hours that the capacity was specified at  
CH   Amp-Hour capacity at the specified discharge rate
R   Discharge rate  
P   Peukert's exponent (about 1.24 for flooded lead-acid, 1.12 for AGM)  

Amp-Hours = (Reserve Minutes * 0.4237) + 14.5 (calculated from an Excel spreadsheet)

% Charge

Specific Gravity

(Open Circuit)











1.217 12.37







40 1.148 11.96
30 1.124 11.81
20 1.098 11.66
10 1.073 11.51

from Trojan Battery User's Guide

Batteries – Dry Cell




Number Cells

Flashlight - Black




Flashlight - Mag-Lite, black


D 2
Flashlight - Dive light


C 4
GPS - Garmin




Penlight - Black w/ red lens




Penlight - Mag-Lite, blue 3 AA* 2
Dinghy navigation lights 2 AA* 4
FRS radios 2 AA* 3
Headlamp (red/white) 1 AAA* 2
Flashlight - Rocky LED 2 AAA* 3
Thermometer 3 AAA 1
Digital calipers 1 LR44 1
Visor clip-on 1 CR2032 2

                                                                * Rechargeable available

Battery Combiner

Hellroaring Technologies, Inc. Model BIC-75150A S/N A01C3337 (5/01). This is wired to isolate the starting battery and the boat runs everything on the house battery. The starting battery is only used for starting the engine. Replaced the first unit that failed (internal MOSFET blown).

Electrical Panel

Made by Bass Products, Inc.

Panel is 791004A

Light is 791001

20 DC breakers arranged 2 x 10 and 5 AC breakers

Circuit Breakers:

Airpax, 8641 Line, Model UPG6-1-52-103-91 (Black Handle)

Carlingswitch Model  AA1-X0-00-905-XD1-C (Black Handle)

Installed a Galvanic Isolator on the AC ground (4/1999).

The Lectra/San circuit breaker (75 amps) is located in the engine compartment on the port side.





Water Heater 15
Battery Charger 15
Spare 50
AC Outlets ?




Cabin Lights 15
Running Lights 15
Anchor Light 5
Mast Light 15
Deck Lights 15
Sump Pump 15
Water Pressure 15
Spare 50
Radar 15





Bilge Pump 15
Autopilot (AP) 20
Radio 40
Tri-color Light 10
Washdown 15
Instrument Lights 15
Refrigerator 15
Instruments 10
Stereo 10
Inverter 40

Pump Panel

Located under galley sink. This controls the pumps (and the fuses for) the refrigeration pump, the freshwater pressure pump, and the galley seawater pressure pump. The panel was custom made by M & I Systems based on my .DXF design.


FB1 - Fuse Block 1 (Port Top)

ID Type Size Comments
FB1-0 ATC 2A Battery combiner ground
FB1-1 ATC 5A Engine room light
FB1-2 ATC 2A BATT1 sense to Link 2000 (blue wire)
FB1-3 ATC 30A Battery Combiner A
FB1-4 ATC 5A Upper bilge pump
FB1-6 ATC 5A Lower bilge pump



FB1-1 FB1-2
FB1-3 FB1-4



FB2 - Fuse Block 2 (Port Bottom)

ID Type Size Comments
FB2-1 ATC 30A Battery combiner C
FB2-2 ATC 2A BATT2 sense to Link 2000 (violet wire)


FB1-1 FB1-2


FB3 - Fuse Block 3 (Starboard)

ID Type Size Comments
FB3-1 AGC 2A Ideal Regulator shunt protection
FB3-2 AGC 20A Power to Ideal Regulator
FB3-3 -- --  
FB3-4 AGC 2A Ideal Regulator shunt protection

Other Fuses

Location Type Size
SSB RT Head(1) AGC 5A
SSB RT Head(2) AGC 5A
A/P FS1 Auto 30A
A/P FS2 Auto 5A
A/P FS3 Auto 5A
A/P FS4 Auto 5A
Lectra/San MDL 35A
Lectra/San MDL 30A
Lectra/San MDL 6A
Lectra/San 5x20mm 5A fast-acting
Furuno GPS 5x20mm 1A

Galvanic Isolator

Installed behind electrical panel. From Yacht Corrosion Consultants (Professional Mariner) Zinc Saver: Installed 1999.


Location Manufacturer Model No. Lamp Bulb/Base Amps Notes
Bow nav light Aqua Signal Series 40 25W 90002-7 T-8/BAY15D    
Stern light Aqua Signal Series 40 10W 90005-7 T-8/BAY15D    
Tachometer     IA62995 (1 or 2 candle-power, wedge base)      
Engine Gauges     1893 (Dialight LED p/n 585-4213 ultra-red $6, LedLight p/n BF321CR3K-14V-P). Can also use 756, 1813, 1889, or 1892 lamps (>13V). T-3/BA9S 0.33  
Steaming Light Perko 964 DP CHR 71 DP CLR (10W, 8CP)      
Dome light - nav station ABI 7" White: 20W halogen (G4), pins 0.184" apart, height 0.882
Red: 10W halogen
G4   Replaced white light with Sensibulb LED light
Spreader Deck Lights ?? ?? GE 4411-1 35W 300 hours      
Cabin reading lights Bass Products 10-2222 (double swivel),
10-2162 (single swivel)
94 (default)
G-6/BA15D 0.58
6 CP, 75 lumens
15 CP, 188 lumens
15 CP, 190 lumens
21 CP, 264 lumens
BA15D 0.33 410 lumens, 2700K
(Replaced all 6/2016)
Chart light Hella   Osram 3386X or Trifa 1639 BA9S 0.50 85 lumens
Tricolor/Anchor Orca Green Marine LXTA-P LED n/a 0.50 Photocell on anchor light (replaced 12/2008)


Lamp Base Information

Designation Description Diameter
BA15D   Bayonet, double contact 15 mm
BA15S   Bayonet, single contact 15 mm
BA9S Miniature bayonet, single contact 9 mm
BAY15D   Bayonet, double contact, indexed 15 mm

T-3 Incadescent mini bayonet-base lamps for engine instrument gauges:

Lamp NAED Volts Amps Candela Hours
756 35771 14.0 0.08 0.3 15,000
1815 37329 14.0 0.20 1.4 3,000
1816 37333 13.0 0.33 3.0 1,000
1893 37505 14.0 0.33 2.0 2,500
3386X   12.0 0.50 6?  

I had a problem with the 1893 lamps turning black (silver?) just running the instruments overnight. I installed a diode in-line with the positive feed, which dropped the voltage 0.7V and stopped the lamp problem.

To convert from candela to lumens:

Lumens = Candela * 2 * π * (1 - cos(θ/2))

θ in radians.

The following is the section from the COLREGs about lamp brightness:

8. Intensity of lights

(a) The minimum luminous intensity of lights shall be calculated by using

the formula:

I = 3.43 x 106 x T x D2 x K-D


I is luminous intensity in candelas under service conditions.

T is threshold factor 2 x 10-7 lux.

D is range of visibility (luminous range) of the light in nautical miles,

K is atmospheric transmissivity. For prescribed lights the value of K

shall be 0.8, corresponding to a meteorological visibility of

approximately 13 nautical miles.


Lightning Protection

From Dr. Charles Moore, New Mexico Tech

The rig is bonded to underwater through the engine (at least for now). Green 6 AWG wire used throughout (2002).

Noise (EMF) Reduction

To reduce pump noise in the refrigeration pump:

Opened up the pump and put a 0.1 F cap across the power leads at the brushes. Also, put a reversed-bias diode across the capacitor to kill back-EMF. Also, connected the ungrounded metal case to the power supply ground.

To reduce refrigeration hum in SSB:

Grounded unused conductors in thermistor lead to the metal chassis ground of the refrigeration unit.

Terminal Blocks

Bilge Pumps (LBP-Lower Bilge Pump, UBP-Upper Bilge Pump). Located under floorboard near engine inlet strainer.

A-Screw Circuit B-Screw
Wire 38-R TB1-1 LBP-Brown
Breaker Switch TB1-2 LBP-Brown/White
Wire 38-B TB1-3 LBP-Black
Wire 39-B TB1-4 UBP-Black
Wire 39-R TB1-5 UBP bilge switch
-- TB1-6 UBP-Brown/bilge switch


Towed Water Generator

Hamilton Ferris

Prop - plastic 8" x 5" three-bladed prop (OMC 386587, $50).

Diodes - 1N1200A 12A, Vf 0.95V @ 5A 25C. Can be replaced with IR 63CPQ100, 100A, Vf 0.6V @ 5A 25C

Tricolor/Anchor Light

Orca Green Marine, model LXTA-P. This is an LED-based combo light at the top of the mast. Measured current @12V of 0.4A for either one being on. The anchor light turns off at sunrise with a built-in photocell in the green sector.

The light has a waterproof connector on the bottom. The mating cable is a Conxall Nano-Mizer 603ST2. The included cable has 24 AWG wires. The contacts are gold-plated.

My original unit failed with water intrusion. OGM replaced it under warranty 12/2008.

Tricolor Pinout


ID Color AWG Description
AP Sheath 14 Circuit breaker "Autopilot" to autopilot
B0 B 6 Ground from battery charger to Link 2000 shunt
B1 R 6 Positive from battery charger to House Bank
B2 R 6 Positive from battery charger to Starting Battery
10 R 8 Starting Battery to fuse block FB2-3
11 R 8 House Bank to fuse block
12 R 10 Fuse block to Battery Combiner "C" (Starting Battery)
13 R 10 Fuse block to Battery Combiner "A" (House Bank)
14 R 10 Battery Combiner Ground to Fuse block
15 R 16 Fuse block to ground on sense resistors
16 R 6 Circuit breaker "Radio" to SSB/VHF
17 B 6 SSB/VHF to Link 2000 ground shunt
18 B 2/0 Engine block to Link 2000 ground shunt
19 R 2/0 Positive from House Bank to distribution stud
20 B 2/0 Negative from House Bank to Link 2000 ground shunt
21 R 2/0 Starter bank +
22 B 2/0 Starter bank -
23 R/B 16 Fuse box to fresh water pump
24 R/B 16 Fuse box to refrigeration pump, icebox fan
25 R/B 16 Fuse box to seawater pump
26 R/B 16 Power to fuse box for pumps
27 B 2 Lectra/San -
28 R 2 Lectra/San +
29 R 2 House + to Lectra/San circuit breaker
30 R/B 16 Anchor light
31 R/B 16 Steaming light
33 R/B 16 Deck lights
34 R/B 10 Tricolor
35 R/B 12 Lower navigation lights
36 P 16 Engine alarm connection
37 Br 16 Regulator power
38 R/B 16 Fuse box to lower bilge pump
39 R/B 16 Fuse box to upper bilge pump

B - black, R - red, P - purple, Br - brown

All green wires are for bonding. The 6 AWG wire is for lightning bonding and 8 AWG wire is for cathodic bonding.