7_Attachment 22 - NSWCCD-23-TM-2009-59 Rev B Ungrounded Electrical Systems Verification Test.pdf

Naval Surface Warfare Center Carderock Division Bethesda, MD 20817084-5700

NSWCCD-23-TM-2009/59 Rev B October 2009

Ship Systems Integration and Design Department

Technical Memorandum

U.S. NAVY BOAT UNGROUNDED ELECTRICAL

SYSTEM VERIFICATION TEST

by

Bill Stavenger

Combatant Craft Division (23)

DISTRIBUTION STATEMENT A. Approved for public release;

distribution is unlimited.

N S

W C

C D

-2

-T M

-2

/5 R e v

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N a v y B o a t U n g ro u n d e d E le c tr ic a l S y s te m V e ri fi c a ti o n T e s t

U.S. NAVY BOAT UNGROUNDED ELECTRICAL

SYSTEM VERIFICATION TEST

NSWCCD-23-TM-2009/59 Rev B

Post-Release Revisions

Revision Reviewer/ Approver

Date Change Description

Page, Section

A M. Riley 23 11/8/10 Editorial Numerous

B Kevin Burns 232 6/30/12 Technical Numerous

REPORT DOCUMENTATION PAGE

Form Approved

OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202- 4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS.

1. REPORT DATE

15-10-2009

2. REPORT TYPE

Final

3. DATES COVERED (From - To)

Oct 2009 to Nov 2010

4. TITLE AND SUBTITLE

US Navy Boat Electrical System Verification Test

5a. CONTRACT NUMBER

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

6. AUTHOR(S)

William (Bill) Stavenger

5d. PROJECT NUMBER

5e. TASK NUMBER

5f. WORK UNIT NUMBER

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) AND ADDRESS(ES)

NAVSEA Carderock

Surface Warfare Center Division

Combatant Craft Division

2600 Tarawa Court, Suite 303

Virginia Beach, Virginia 23459-3239

8. PERFORMING ORGANIZATION REPORT

NUMBER

9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES)

Attn: PEO SHIPS, PMS 325G

Commander

Naval Sea Systems Command

1333 Isaac Hull Avenue, SE Building 197

Washington Navy Yard, DC 20376

10. SPONSOR/MONITOR’S ACRONYM(S)

PMS325G

11. SPONSOR/MONITOR’S REPORT

NUMBER(S)

12. DISTRIBUTION / AVAILABILITY STATEMENT

DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited.

13. SUPPLEMENTARY NOTES

14. ABSTRACT

This document describes the procedure to verify that the electrical system is ungrounded, confirming that the hull (for metal craft); or the bonding system or engine block (for non-metal craft) is not at battery bank negative polarity potential.

15. SUBJECT TERMS

Electrical, ungrounded, test

16. SECURITY CLASSIFICATION OF:

17. LIMITATION

OF ABSTRACT

18. NUMBER

OF PAGES

19a. NAME OF RESPONSIBLE PERSON

Scott Petersen

a. REPORT

Unclassified

b. ABSTRACT

Unclassified

c. THIS PAGE

Unclassified

See 12.

19b. TELEPHONE NUMBER

757-462-3107

Standard Form 298 (Rev. 8-98)

Prescribed by ANSI Std. Z39.18

This page intentionally left blank

Contents

Page

Administrative Information

Acknowledgements

Summary

Introduction

Background

Objective

Scope

Test Set-up

Prerequisites

Test Equipment

Safety Notes

Test Procedure

Step 1: Battery Bank Voltage

Step 2: Voltage Measurement

Step 3: Electrical Resistance Measurement (Base Electrical System):

Step 4: Leakage Current Test Wiring Connection:

Figure 1. Leakage Current Test Wiring Connection

Step 5: Starting Battery Bank Leakage Current Test:

Step 6: House (or Ship Service) Battery Bank Leakage Current Test:

Step 7: Resistance Check for Unintentional Grounded Loads:

Table 1: Known Grounded Equipment(Last Update – Sep 2012)

Table 2: Known Ground Problems with Resolutions (Last Update – Sep 2012)

Table 3: Known Ground Problems with Mitigation (Last Update – Sep 2012)

Step 8: Restoration

Test Results

References

Distribution

Administrative Information This test procedure was developed by the Combatant Craft Division (Code 23) of the

Ship Systems Integration and Design Department at the Naval Surface Warfare Center, Carderock Division (NSWCCD). This effort was sponsored by the US Navy Small Boats

Program Office, PMS 325G, in support of all small craft acquisitions.

This document (NSWCCD-23-TM-2009/59 Rev B October 2009) replaces Revision A of the original document, which is obsolete and should be destroyed.

Acknowledgements The author wishes to thank Mr. J.M. Coughlin, Program Manager at the US Navy Small

Boats Program Office (PEO Ships, PMS 325G), for sponsoring the original development of this guide, and Mr. Denis Bushey, PMS 325G for his overall management direction for revision A.

Rodney Keith and Kevin Burns provide valuable review comments and technical updates for

Revision B, and Mr. Michael Riley served as technical editor. The collective support of all these individuals is sincerely appreciated.

Summary

The test procedure described herein is provided for guidance and information to builders offering boats for U.S. Navy service on the General Services Administration (GSA) Federal

Supply Schedule (FSS). Unless specifically invoked in a contract, this document is for guidance only and is not contractually binding and does not supersede any contract requirement.

This document reflects accepted practices and Government preference unless otherwise directed in the contract. Consult the contract Technical Point of Contact (TPOC) for clarification or resolution if any aspect of this document conflicts technically with a contract requirement.

When accomplishment of this document is required by contract, delivery of test results will be in accordance with that contract.

Introduction

Background

Ungrounded power systems are required on all U.S. Navy small boats and craft . The ungrounded system provides a high level of protection for personnel and supports the continued operation of equipment. Since the perfect ungrounded system does not exist, personnel should never intentionally come in contact with any conductor or work on the system while energized as the possibility of shock, though minimized, still exists.

Objective

The purpose of this test procedure is to verify that a craft’s electrical system is ungrounded. Successful testing confirms that the hull for metal craft, or the bonding system or engine block for non-metal craft is not grounded (i.e., at battery bank negative polarity potential).

The layout of this guide includes test procedures as well as “TIPS” that highlight lessons learned and cautions for avoiding common issues.

Scope

This guide is generally applicable to the design, fabrication, and certification of safe and effective electrical systems for US Navy small boats. It conveys typical government preferences and expectations as an educational tool for builders offering boats on the General Services

Administration (GSA) Federal Supply Schedule (FSS). Unless specifically invoked in a contract, the information contained herein is not contractually binding and does not supersede contract requirements.

Test Set-up

Prerequisites

1. The battery banks should be fully charged. Battery bank terminal voltage of no less than

25 VDC is required for each battery bank.

2. The resistance readings should be measured and recorded using a multi-meter set to the ohms scale.

3. The test should be performed only by personnel familiar with shipboard electrical systems, a journeyman electrician or an electrician helper.

TIP: Do not perform the test if any craft battery bank voltage is less than 25 VDC.

Test Equipment

1. Multi-meter, Fluke 87, 179 or equal with working ammeter function (no blown fuses).

2. 1 Each - Resistor, Wire Wound (Aluminum Housed), 5 ohm, 230 Watt

Model WFH230L5R0JE

Source: Mouser Electronics, 382 Rt. 46, Suite 1 & 2, Budd Lake, NJ. 07828. Phone Number: 800-346-6873)

3. Toggle switch, Single Pole Double Throw, On-Off On (momentary)

Bat-Handle style w/ 1/4 tab

Pt # 555025

Source: West Marine

4. Hook-up Wire, 16 AWG (Grey) 25’ Spool

Pt # 182403

Source: West Marine

5. Assorted Connectors and crimp tool

Pt # 220002

Source: West Marine

6. ATO/ATC fuse holder with 7.5 ampere ATC Fuse

PT # 6557532, Source: West Marine

Safety Notes

1. Ensure personnel are familiar with operation of the craft electrical system.

2. Utilize personal protection equipment as required

3. Ensure that the craft master is notified before energizing or de-energizing any electrically operated equipment or device.

Test Procedure

Step 1: Battery Bank Voltage

Measure and record battery bank voltages with the battery switches in the off position.

Battery Bank Voltage (Vdc)

Engine

Ship

Service/House

Battery voltages must be 25 Vdc or greater in order to proceed with the test.

Test Mechanic ___________________________________ Date _____________

Step 2: Voltage Measurement

Verify all DC equipment is switched off. Disconnect the positive battery cable from the battery and put the respective battery isolation switch in the “On” position. Using a multi-meter selected to DC voltage, measure the voltage from the battery positive terminal (red meter probe) and the disconnected battery positive cable (black meter probe). If 24 Vdc is present, then either a piece of DC equipment is switched on or leakage current is present. Re-verify all DC equipment is turned off. If voltage is still present, then record voltage below and continue to Step 3.

Voltage Measurement (Start Battery Bank) ______________ (Desired reading is 0 Vdc)

Voltage Measurement (House Battery Bank) _____________ (Desired reading is 0 Vdc)

Step 3: Electrical Resistance Measurement (Base Electrical System):

Reconnect the positive battery cable and disconnect the negative battery cable. Open all DC circuit breakers. Using a multi-meter selected to the ohms scale, measure and record the electrical resistance reading between the hull (for metal craft); or the bonding system or engine block (for non-metal craft) and the negative common battery bus. Ensure that no voltage is present prior to this measurement. Any reading below the desired reading of 1 Mohm, troubleshoot and determine source of ground. If ground persists, then contact NSWCCD for resolution. Record detailed troubleshooting notes on sheet 11. Proceed to steps 4 and 5.

Resistance Measurement _____________________ (Nominal reading is 1 Mohm)

Step 4: Leakage Current Test Wiring Connection:

Connect the test set up wiring as shown in Figure 1, Test Wiring Connection.

Figure 1. Leakage Current Test Wiring Connection

Step 5: Starting Battery Bank Leakage Current Test:

All 12 and 24 VDC panel breakers must be in the “OFF” position. Set the fluke multi-meter to

DC amperes function. Ensure that the meter leads are plugged into the multi-meter ammeter test jacks. Verify that the toggle switch is connected so that continuity through the switch is made only when the bat handle is held closed in the momentary “ON” position. Connect the positive meter lead to the positive battery terminal. Close the associated battery disconnect switch. Hold the test toggle switch in the momentarily “ON” position. Observe current reading from the multi-meter.

Caution: Holding the test toggle switch in the “ON” position for an extended length of time may cause the test resistor to heat up.

If amperage greater than 0.001 amperes is detected on the multi-meter display, troubleshoot to locate source of stray current. Begin with isolation of the negative bus by first lifting the alternator and the starter negative leads for each engine from the negative common terminal bus in the engine room. Continue to isolate each negative cable lead, performing the amperage test for the associated battery after each time a lead is lifted.

If stray current persists, then contact NSWCCD for resolution. Record detailed troubleshooting notes on sheet 12. Record final current reading from the multi-meter. Proceed to step 6. Secure battery switch when finished.

Multi-meter Current Measurement __________ (Desired reading is zero (0) amperes.

Nominal reading is 0.001 amperes)

TIP: A multi-meter amp reading greater than 0.001 amperes indicates a possible system ground.

Step 6: House (or Ship Service) Battery Bank Leakage Current Test:

All 12 and 24 VDC panel breakers must be in the “OFF” position. Set the multi-meter to DC amperes function. Ensure that the meter leads are plugged into the multi-meter ammeter test jacks. Verify that the toggle switch is connected so that continuity through the switch is made only when the bat handle is held closed in the momentary “ON” position. Connect the positive meter lead to the positive battery terminal. Close the associated battery disconnect switch. Hold the test toggle switch in the momentarily “ON” position. Observe the current reading on the multi- meter.

If amperage greater than 0.001 amperes is detected on the multi-meter display, troubleshoot to locate source of stray current. Begin with isolation of the negative bus by first lifting the alternator and the starter negative leads for each engine from the negative common terminal bus in the engine room. Continue to isolate each negative cable lead, performing the amperage test for the associated battery after each time a lead is lifted.

If stray current persists, then contact NSWCCD for resolution. Record detailed troubleshooting notes on sheet 13. Proceed to step 7. Record the final current reading on the multi-meter.

Secure battery switch when finished.

Multi-meter Current Measurement __________ (Desired reading is zero (0) amperes.

Nominal reading is 0.001 amperes)

TIP: A multi-meter amp reading greater than 0.001 amperes indicates a possible system ground.

Test Mechanic ___________________________________Date _____________

Step 7: Resistance Check for Unintentional Grounded Loads:

Lift the negative battery cable(s) from battery banks(s). Lift the negative lead from all

“known/accepted” grounded components (see Tables 1, 2 & 3). Close all feeder and individual load circuit breakers. Using a multi-meter set on resistance scale, measure resistance from each negative battery cable to the hull (for metal boats) or to the bonding system or engine block on fiber reinforced plastic (FRP) craft. If the reading is less than 1 Mohm, then systematically open circuit breakers to isolate/identify the potentially grounded load on the boat. Clear any unintentional grounds and repeat test until 1 Mohm or nominal reading of 25 Kohms is achieved.

If ground persists, then contact NSWCCD for resolution. Record detailed troubleshooting notes on sheet 14. Proceed to step 8.

Multi-meter Resistance Measurement __________ (Desired reading is 1 Mohm, Nominal reading is 25 Kohms)

Table 1: Known Grounded Equipment(Last Update – Sep 2012)

Equipment Typical Resistance to ground

Isolation Method During Test

Cummins Inboard Engines with

Smartcraft version 1.xx (ECM)

5.6 Kohms Open ECM circuit breaker

Cummins Inboard Engines with

Smartcraft version 2.xx (ECM)

5.6 Kohms Open ECM and VIP circuit

breakers

Outboard Engines Less than 1 Kohms Isolate negative lead

Smoke Launcher Less than 1 Kohms Isolate with Double Pole Circuit

Breaker

Table 2: Known Ground Problems with Resolutions (Last Update – Sep 2012)

Equipment Cause of Ground Resolution

Furuno Radar Scanner

(1834C/Navnet 2D vx2

Scanner ground strap Removed ground strap (per

OEM)

Fuel Senders Sender touching baffles in tank

Corrected installation

Fuel Gauges Negative terminal shorted to case

Replaced

NATO shore power receptacle Isolator misaligned or installed backwards

Corrected installation

Engine starter (Inboard

Diesel)

Incorrect (grounded type) starter installed

Replaced with isolated starter per contract

Engine starter (Inboard

Diesel)

Starter negative connection touching starter case

Corrected installation

Engine starter (Inboard

Diesel)

Ground strap from starter negative terminal to engine block

Remove OEM ground strap

General – Component

Selection

Chassis- or Case-grounded electrical component installed

Replace with isolated / ungrounded component or externally isolate

General - Wiring Wiring insulation damaged, touching ground potential

Corrected installation

Table 3: Known Ground Problems with Mitigation (Last Update – Sep 2012)

Equipment Cause of Ground Mitigation

Trim Pump (Mercruiser sterndrive – 7m RIBs)

Unknown Low resistance reading (6

Kohms) on some pumps accepted due to no leakage current found

Mercruiser Tachometer with

LED display (11mRIB’s)

OEM investigating Pending

Step 8: Restoration

Remove all test equipment. Restore all cables and leads removed during the performance of this procedure. Close any electrical enclosures as required. Restore the craft to pretesting condition.

Test Results Ensure that all data in the procedure are filled in as practicable. Add any comments concerning this procedure to the remarks sheet.

Craft restored to pretest condition

Following only applicable if this test is specifically invoked in a contract and completed copy of this document is a contract deliverable for specified hull(s).

Contract No.: __________________________________________

Hull No.:______________________________________________

Date Submitted:________________________________________

Government Reviewer ___________________________________Date _____________

Test Data Reviewed Sat / Unsat (circle one)

Government Reviewer Comments:

Troubleshooting Notes for Step 3:

(include all steps taken, changes in readings, which components were isolated, etc)

(Signature / Date)

Troubleshooting Notes for Step 5:

Troubleshooting Notes for Step 6:

Troubleshooting Notes for Step 7:

References

1. Burns, Kevin, U.S. Navy Boat Electrical Practices, Naval Surface Warfare Center

Carderock Division report NSWCCD-23-TM-2009/58 Rev A, 8 November 2010

2. Collier, Everett, The Boatowner’s Guide to Corrosion, Camden, ME. International

Marine/McGraw-Hill, 2006.

3. Calder, Nigel, Boatowner’s Mechanical and Electrical Manual, Camden, ME.

International Marine/McGraw-Hill, 1996.

4. Payne, John C., The Marine Electrical and Electronics Bible, Dobbs Ferry, NY, Sheridan

House, 1998

Distribution

Copies Copies

Naval Sea Systems Command

PEO SHIPS

1333 Isaac Hull Avenue SE

Washington Navy Yard, DC 20376-2101

# NSWC, CARDEROCK DIVISION

INTERNAL DISTRIBUTION

1 Code Name

23 Electronic Data Library 1