THE ELECTRICAL SIDE OF INSTALLING ELECTRONICS ON

BOATSCHARLIE JOHNSON

JTB MARINE CORPORATIONcjohnson@jtbmarine.com

727.560.9065HUDSON BEACH YACHT CLUB MEETING

SEPTEMBER 4, 2012

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Charlie has been active in marine engineering for most of his professional career. A registered professional mechanical engineer in two states, he is a retired Naval Officer with extensive ship management and ship handling experience. He began his Naval career as the Chief Engineer of a salvage vessel that saw extensive action during the Vietnam War. After his Chief Engineer’s tour, he began a career as an Engineering Duty Officer specializing in nuclear submarine maintenance, design and certification.

In the late 1990’s, Charlie and his wife, Lari, prepared their 53’ Gulfstar Long Range Trawler for a three year trip to the Eastern Caribbean where they practiced retirement.

In 2001, he formed JTB Marine Corporation, a company dedicated to providing standards based, technically strong services to the boating public, boat builders, and commercial fishermen. JTB Marine’s work scope includes standards based designs, concise troubleshooting, and the performance of meticulous installations of electrical and electronic systems and components on private yachts and commercial vessels in the 35’ to 110’ range.

Charlie also performs electrical and corrosion surveys and provides forensic engineering and accident investigation services aboard all types of vessels. His most recent forensics’ experience includes investigations to determine the origin and cause of fires aboard two private vessels and determining the cause of stray current damage at a municipal marina.

Recently became a partner in Clean eMarine-Americas (http://www.c-e-marineamericas.com), to build and distribute the Danish Thoosa and Triton brand of electric propulsion systems

Charlie Johnson, PE

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SOMEBODY INVOLVED WITH THE INSTALLATION OF ANY ELECTRICAL EQUIPMENT ABOARD YOUR BOAT NEEDS TO GO THROUGH THIS THOUGHT PROCESS

IF NOT YOU, THAN CERTAINLY YOUR TECHNICIAN MUST BE KNOWLEDGEABLE

BORING BUT IMPORTANT STUFF

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VOLTAGE DROP AND AMPACITY

IN-LINE FUSES

OUR SIZZLING TOPICS FOR THIS EVENING

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WOW!! FEEL THE EXCITEMENT!!!

OUR SIZZLING TOPICS FOR THIS EVENING

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VOLTAGE DROP IS THE MANIFESTATION OF MR. OHM’S LAW: VOLTAGE = CURRENT X RESISTANCE

E = I X R REMEMBER YOUR ALGEBRA (MATH IS FUN ☺)

INCREASING THE CURRENT ➔ INCREASES VOLTAGE DROP

INCREASING THE RESISTANCE ➔ INCREASES VOLTAGE DROP

SIZZLING TOPIC #1: VOLTAGE DROP

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CONDUCTORS HAVE RESISTANCE (EXPRESSED IN OHMS); THE “R” IN MR. OHM’S LAW

THE ELECTRICAL RESISTANCE OF CONDUCTORS INCREASES AS THEIR LENGTH INCREASES

THE ELECTRICAL RESISTANCE OF CONDUCTORS INCREASES AS THE CROSS SECTIONAL AREA OF THE CONDUCTOR DECREASES

VOLTAGE DROP

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FROM THE AMERICAN BOAT AND YACHT COUNCIL STANDARDS AND TECHNICAL INFORMATION REPORTS FOR SMALL CRAFT, 2012-2013

11.4.2.6 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.

VOLTAGE DROP

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A NEW AND EXCITING TERM: AMPACITY AMPACITY IS THE MAXIMUM AMOUNT OF ELECTRICAL

CURRENT A CONDUCTOR OR DEVICE CAN CARRY BEFORE SUSTAINING IMMEDIATE OR PROGRESSIVE DETERIORATION. FOR CONDUCTORS, AMPACITY IS A FUNCTION OF THE THE

ABILITY OF THE CONDUCTOR’S INSULATION AND TO A LESSER EXTENT, THE CONDUCTOR ITSELF TO REMAIN INTACT UNDER LOAD

AMPACITY DECREASES WITH AN INCREASE IN AMBIENT TEMPERATURE

AMPACITY DECREASES WITH THE ADDITION OF BUNDLED, CURRENT CARRYING CONDUCTORS

VOLTAGE DROP

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ABYC STANDARDS SPECIFY : 11.14.2.1.1 The construction of insulated cables

and conductors shall conform with the requirements of:

11.14.2.1.1.1 UL 1426, Cables for Boats, or 11.14.2.1.1.2 the insulating material temperature

rating requirements of: 11.14.2.1.1.3 SAE J378, Marine Engine Wiring, and 11.14.2.1.1.4 SAE J1127, Battery Cable, or SAE

J1128, Low-Tension Primary Cable

VOLTAGE DROP

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QUALITY BOAT CABLE; E.G., ANCOR, BELDEN, PACER, ETC. IS RATED AS UL1426, WITH INSULATION THAT IS RATED FOR 105℃ DRY CONDITIONS OR 75℃ WET CONDITIONS

TINNING IS NOT MANDATORY BY THE ABYC STANDARDS, BUT IS CONSIDERED BEST PRACTICE IN THE INDUSTRY

LIKEWISE, TYPE 3 STRANDING IS NOT REQUIRED BY THE ABYC STANDARDS BUT IS CONSIDERED BEST PRACTICE IN THE INDUSTRY

VOLTAGE DROP

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WHEN DESIGNING A CIRCUIT THERE ARE TWO PARAMETERS THAT MUST BE CONSIDERED VOLTAGE DROP

OPERATIONAL CONSIDERATION AMPACITY

SAFETY CONSIDERATION USUALLY, ADEQUATE CONDUCTOR SIZE TO

PROVIDE THE SPECIFIED ALLOWABLE VOLTAGE DROP WILL PROVIDE ADEQUATE AMPACITY…BUT NOT ALWAYS!!

VOLTAGE DROP

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FROM THE ABYC STANDARDS: K x I x LCM = ————— E

Where:CM = Circular mil area of conductorK = 10.75 (constant representing the resistivity of copper)I = Load current in amperesL = 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

VOLTAGE DROP MATH…HOW WE LOVE MATH!☺

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BUT, WE DON’T HAVE TO DO THE MATH (☹) TO FIND A CONDUCTOR SIZE FOR A KNOWN LOAD WITH A KNOWN DISTANCE FROM THE SOURCE IN A KNOWN ENVIRONMENT

BY SETTING E = 12VDC AND E = 24VDC AND USING BOAT CABLE WITH 105℃ INSULATION RATING IN THE CM FORMULA AND THEN CONVERTING FROM CM TO AWG, THOSE NICE FOLKS AT ABYC HAVE GENERATED A COUPLE OF TABLES TO HELP US OUT

VOLTAGE DROP

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THESE TABLES ARE OK, BUT THOSE REALLY NICE FOLKS AT BLUE SEA SYSTEMS HAVE MADE THE DETERMINATION OF CONDUCTOR SIZE EVEN EASIER, AND THERE IS EVEN SOME MATH!!☺

LOOK AT THE VOLTAGE DROP EQUATION AGAIN: CM = (K x I x L) / E

FOR A KNOWN VOLTAGE DROP (E) BLUE SEA DEVELOPED THE CONCEPT OF FOOT x AMPS (I x L)

USING SYSTEM VOLTAGE AND ALLOWED VOLTAGE DROP AND THE PRODUCT OF CIRCUIT LENGTH (L) AND THE LOAD CURRENT(I) ENTER THE FOLLOWING TABLE TO FIND THE PROPER WIRE SIZE

VOLTAGE DROP

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VOLTAGE DROP

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AN EXAMPLE 12 VOLT SYSTEM NEW READING LIGHT TO BE INSTALLED 20’

AWAY FROM THE CONNECTION TO THE CIRCUIT BREAKER PANEL

ACTUAL TO/FROM CIRCUIT LENGTH IS 45’ ELECTRICAL LOAD IS 2A OUTSIDE THE MACHINERY SPACE F-AMPS = 45’ x 2A = 90 F-AMPS

VOLTAGE DROP

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ENTER THE BLUE SEA TABLE WITH 90 F-AMPS, NON MACHINERY SPACES, 12VDC AND 10% VOLTAGE DROP TO FIND THE A NUMBER ≥ 90 F-AMPS

VOLTAGE DROP

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VOLTAGE DROP☟

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ONE MORE EXAMPLE (WE ♡ MATH!) 12 VOLT SYSTEM ANCHOR WINDLASS TO BE INSTALLED WITH AN

ACTUAL TO/FROM CIRCUIT LENGTH OF 52’ FROM THE LOAD SIDE OF THE CIRCUIT BREAKER ADJACENT TO THE STARTING BATTERY

ELECTRICAL LOAD IS 90A INSIDE THE MACHINERY SPACE F-AMPS = 52’ x 90A = =4,680 F-AMPS

VOLTAGE DROP

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ENTER THE BLUE SEA TABLE WITH 4,680 F-AMPS, MACHINERY SPACES, 12VDC AND 10% VOLTAGE DROP TO FIND THE A NUMBER ≥ 4,680 F-AMPS

VOLTAGE DROP

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VOLTAGE DROP☟

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WHY DO WE CARE ABOUT VOLTAGE DROP? ALL ELECTRICAL LOADS HAVE A VOLTAGE AND

A CURRENT SPECIFICATION EXAMPLE: THE POPULAR ICOM MARINE

SSB/HAM M802 SPECS 30A MAXIMUM 13.6VDC ±10%

VOLTAGE DROP

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LET’S HAVE MORE FUN WITH MATH!! ☺ 13.6VDC + 10% = 13.6VDC + 1.36VDC =

14.96VDC REASSURING: THE MAGIC SMOKE WON’T COME

OUT OF THE BOX WHEN CHARGING WITH THE ALTERNATOR OR THE CHARGER. THIS IS GOOD.

13.6VDC – 10% = 13.6VDC -1.36VDC = 12.24VDC REASSURING: MAYBE. WE’LL HAVE TO COME

BACK TO THIS.

VOLTAGE DROPICOM 802

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OH BOY, MORE MATH AND ELECTRICAL FORMULAE (DON’T YOU JUST LOVE THIS STUFF?♡)

SPEC IS FOR 30A MAX CURRENT DRAW @ 13.6VDC POWER = CURRENT X VOLTAGE P = I X V (POWER IN WATTS; I IN AMPS; V IN VOLTS) FROM THE SPEC’S A NOMINAL 13.6VDC AND 30A ON

MAX OUTPUT RF POWER WOULD YIELD AN INPUT POWER REQUIREMENT OF : P = 30A X 13.6VDC = 408W

VOLTAGE DROPICOM 802

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SO THE POWER REQUIREMENT FOR MAX RF OUTPUT IS 408W

MORE MATH!!☺ 12.24VDC IS THE BOTTOM OF THE ALLOWABLE

VOLTAGE RANGE AND WE NEED 408W FOR MAX RF OUTPUT

P = I X V ➯ I = P / V PLUGGING AND CHUGGING THE NUMBERS:

I = 408 / 12.24 = 33.33A

VOLTAGE DROPICOM 802

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THE ICOM 802 MAIN UNIT IS GOING TO BE LOCATED SUCH THAT THE CIRCUIT LENGTH FROM THE HOUSE BANK CIRCUIT BREAKER IS 30’, THE HOUSE BANK IS IN THE ENGINE COMPARTMENT, THE SYSTEM IS 12VDC AND ALLOWING FOR MAXIMUM RF OUTPUT AT MINIMUM BATTERY VOLTAGE, LOAD CURRENT IS 33.3A

WHAT SIZE CONDUCTOR IS REQUIRED? F-AMPS = 30’ x 33.3A = 999 F-AMPS

VOLTAGE DROPICOM 802

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DON’T FORGET… FROM THE AMERICAN BOAT AND YACHT COUNCIL

STANDARDS AND TECHNICAL INFORMATION REPORTS FOR SMALL CRAFT, 2012-2013

11.4.2.6 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.

VOLTAGE DROP

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VOLTAGE DROP☟

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ANY QUESTIONS BEFORE MOVING ON TO THE NEXT, EDGE OF YOUR SEAT,

TOPIC?

THAT’S IT FOR VOLTAGE DROP(THANK YOU, SIGHS THE AUDIENCE!)

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SIZZLING TOPIC #2: THOSE IRRITATING, BUT OH SO NECESSARY, IN-LINE FUSES

ATO/ATC FUSE HOLDER(BLADE TYPE)

AGC FUSE HOLDER-DRIP PROOF(GLASS TYPE)

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WE HAVE TWO ISSUES: PROTECTING THE CONDUCTORS FROM A SHORT CIRCUIT

SITUATION REMEMBER AMPACITY?

PROTECTING THE EQUIPMENT HOWEVER, MANY ELECTRONIC DEVICES REQUIRE CIRCUIT

PROTECTION AS LOW AS 1A. ELECTRONICS’ MANUFACTURES GENERALLY PROVIDE A

FACTORY INSTALLED IN-LINE FUSE HOLDER IN THE B+ CONDUCTOR TO THE PIECE OF ELECTRONIC EQUIPMENT THIS FUSE HOLDER IS OFTEN OF POOR QUALITY AND PRONE TO

WATER INTRUSION

IN-LINE FUSES

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RECENTLY ON A 44’ CALIFORNIAN MOTOR YACHT THE “WIGGLE IN” FLYING BRIDGE ACCESS SPORTED

NO FEWER THAN SIX FACTORY INSTALLED AGC IN-LINE FUSES UNDER THE DASH

THE TILT BACK LOWER STEERING STATION HAS THREE FACTORY INSTALLED AGC IN-LINE FUSES

ESSENTIALLY IMPOSSIBLE, OR AT LEAST VERY DIFFICULT, TO QUICKLY CHECK TO SEE IF A FUSE IS BLOWN IF THE ELECTRONIC EQUIPMENT DOES NOT POWER UP

IN-LINE FUSES

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A SOLUTION THAT SOMETIMES WORKS.

IN-LINE FUSES

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THOSE NICE FOLKS AT BLUE SEA SYSTEMS HAVE JUST COME OUT WITH ANOTHER OPTION…MY OPINION IS THAT IT IS JUST ABOUT IDEAL!

IN-LINE FUSES-A BETTER WAY

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IN-LINE FUSES-A BETTER WAY

Independent Sourced Circuit ST Blade Fuse Block

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IN-LINE FUSES-A BETTER WAY

Independent Sourced Circuit ST Blade Fuse Block

B+ IN FROMSOURCES

B+ OUT TO INDIVIDUAL

LOADS

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VOLTAGE DROP AND ITS IMPORTANCE AMPACITY AND ITS IMPORTANCE CONDUCTOR SIZING, THE EASY WAY HOW TO PROTECT YOUR EXPENSIVE

ELECTRONICS WITHOUT USING CONVENTIONAL IN-LINE FUSES BURIED BEHIND THE JOINERY

SUMMARY

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QUESTIONS

PLEASE BE KIND!