Electronic Installation Practices Manual - Chapter 9 - Cabling - NAVSHIPS 900171

SECTION 5

NUMBERING CABLES AND CONDUCTORS

1. INTRODUCTION.

All ships cables are identified by metal tags that show the source, relative importance and classification of each cable. Permanently installed ship's cables are tagged as close as practicable to each point of connection, on both sides of decks, bulkheads, and other barriers. The length of cable between cable tags should not exceed 50 feet. Non-vital cables less than 50 feet long and located wholly within the same compartment, so that they may be easily traced, need not be tagged.

2. IDENTIFICATION OF CABLES.

C	- I. C. leads
F	- Ship's service lighting feeders and general power feeders.
FB	- Battle power feeders.
G	- Fire control circuits.
R	- Electronic (radio, radar, and sonar) circuits.
XFE	- Emergency lighting and emergency power feeders.

Feeders that supply power to electronic equipment are identified as is specified for power and lighting circuits, up to the last distribution point preceding the electronic equipment. Then the electronic designations are used on cables from this last distribution point to the electronic loads. Power cables between units of electronic equipment have electronic designations.

3. ELECTRONIC CABLE DESIGNATIONS.

Electronic cables are marked as follows:

EXAMPLE: R-RB3

R	indicates electronics.
RB	indicates an entertainment receiver circuit.
3	indicates cable number 3 of the entertainment receiver circuit.

EXAMPLE: 2R-ES7

2	indicates the second surface search radar circuit on the vessel.
R	indicates electronics.
ES	indicates a surface search radar circuit.
7	indicates cable number 7 of the surface search radar. Note that where 2 or more systems with identical circuit letters are installed, the cable designation is preceded by a number.

3. COLOR BANDING.

All vital and semi-vital electronic cables, except branch and sub-branch circuits, have identification tags colored as follows:

Radio, Radar, Sonar

Vital -	Red
Semi-Vital -	Yellow
Non-vital -	Gray

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Cables having power system designations are color-banded red when supplying vital I.C. and F.C. circuits and yellow when supplying semi-vital circuits.

5. DEFINITIONS.

VITAL CABLES. -Those, which if cut in action, would disable apparatus absolutely necessary to the fighting effectiveness of the ship.

SEMI-VITAL CABLES. -Those which, if cut in action, would disable apparatus that contributes to the fighting effectiveness of the ship but is not absolutely necessary.

NON-VITAL CABLES. - Those which furnish power to apparatus whose loss would not seriously impair the fighting effectiveness of the ship.

6. CLASSIFICATION.

The following classification lists vital, semi-vital and non-vital electronic, I. C. and F.C. circuits with their circuit letter designations. (See Table 9-3a, 9-3b and 9-3c.

For power circuits, the classifications are shown on the feeder lists. For I. C. and F. C. circuits; the classifications are indicated by a note on the respective isometric wiring diagrams.

7. TAGS.

The tags for marking cable are made of colored soft steel, zinc, or aluminum tape.

Figure 9-16 shows dimensions, shape and installation.

8. CONDUCTOR MARKING.

All active conductors of electronic cables are marked by stamping, or by use of branded synthetic sleeving, where terminals are too small to be stamped. Terminals to be inter-connected should be marked identically.

In addition to its own identifying marker. each conductor is marked with the cable designation of which it is a part. This is done by placing a synthetic sleeve or fiber tag, having the cable designation on the conductor, next to the point where the connection is made within a connection box. Spare conductors of each cable are grouped and identified with their cable designations.

Color coding for individual conductors is shown in Tables 9-4 and 9-5.

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	CIRCUIT LETTERS	VITAL (RED)	CIRCUIT LETTERS	NON-VITAL (GRAY)
Radio Communication	R -RA	Radio Transmitting and Receiving Antenna Systems (includes R. F. extension system)	R-RB	Radio Entertained Receiver Circuits (includes both audio and radio frequency distribution circuits)
	IR -RC	Transmitter remote control system circuits (also combined transmitter and receiver control circuits)
	2R-RC	Receiver remote control system circuits
	3R-RC	Teletype circuits
	R-RR	Cables between units of a receiving equipment
	R-RT	Cables between units of a transmitting equipment
Countermeasures	R-CC	Communication countermeasures systems
(R-C)	R-CR	Radar countermeasures systems
	R-CS	Sonar countermeasures systems

TABLE 9-3a
ELECTRONIC SYSTEMS

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	CIRCUIT LETTERS	VITAL (RED)	CIRCUIT LETTERS	NON-VITAL (GRAY)
Beacons	R-BA	Aircraft Beacon Systems
(R-B)	R-BC	Radio Beacon Systems
	R-BR	Radar Beacon Systems
	R-BS	Sonar Beacon Systems
	R-BN	Nancy Beacon Systems

Sonar (R-S)	R-SA	Azimuth Echo-Ranging-listening systems	R-SE	Depth Charge Direction indicators and range estimators
	R-SD	Depth Determining Sonar Systems	R-SM	Sonar Monitoring Circuits
	R-SK	Scanning Sonar Systems	R-SP	Attack Aid and Auxiliary Systems
	R-SL	Sonar Listening Systems	R-SR	Remote Indicator Systems
	R-SO	Bathythermograph Systems	R-SU	Underwater Object Locator Systems
	R-SQ	Combination Depth (Azimuth Sonar Systems)
	R-SS	Sounding (Fathometer) Systems

Search	R-SB	Underwater Telephone Systems
Radar System	R-EA	Air Search Radar Circuits
(R-E)	R-EC	CCA System Circuits
	R-EF	Fighter Director Radar Circuits
	R-ER	Radar Repeater Circuits
	R-ES	Surface Search Radar Circuits
	R-EW	AEW System Circuits
	R-EZ	Zenith Search Radar Cts.

TABLE 9-3b
ELECTRONIC SYSTEMS

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	CIRCUIT LETTERS	VITAL (RED)	CIRCUIT LETTERS	NON-VITAL (GRAY)
Fire Control Radar	R-FB	Guided Missile Fire Control Radar
Systems	R-FG	Heavy Machine Gun Battery Fire Control Radar Circuits
(R-F)	R-FM	Main Battery Fire Control Radar Circuits (6" Guns and Larger)
	R-FS	Double Purpose Battery Fire Control Radar Circuits

IFF	R-IA	Circuits of IFF Equipment Operating in conjunction with Air Search Radar Systems
(R-I)	R-IC	Circuits of Integrated IFF System
	R-ID	Circuits of IFF Equipment Operating in conjunction with Fighter Director Radar Systems
	R-IF	Circuits of IFF Equipment Operating in conjunction with Radar Repeater Systems
	R -IR	Circuits of IFF Equipment Operating in conjunction with Radar Repeater System
	R-IS	Circuits of IFF Equipment operating in conjunction with surface Search Radar Systems
	R-IT	IFF Transponder Circuits

TABLE 9-3c
ELECTRONIC SYSTEMS

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	VITAL CIRCUITS (Light Blue)
G	General alarm and chemical attack system
GA	Torpedo control systems
GE and GEP	Main battery control systems
GH and GHP	Anti-aircraft control systems
GM	Machine gun control systems
GJ and GSP	Secondary battery control systems
GT	Captain's target designation system
JA	Primary battle telephone system
LC	Gyro compass system
1LG, 2LG, 3LG and 4LG	Gyro stabilizer motor generators
5LG	Angle gyro system
1MC to 5MC 11MC to 17MC	General and battle announcing systems (where circuit G is incorporated in MC system)
	SEMI-VITAL (Green)
EP	Telephone and voice tube call bell system (protected calls)
IEC and 2EC	Lubricating oil low pressure alarm systems
K	Shaft revolution indicator system
L	Steering telegraph system

	NON-VITAL (Green) Cont'd.
1MB and 2MB	Engine order telegraph systems
1MC to 6MC	General and battle announcing systems where circuit G is not incorporated in MC systems
21 MC and Similar Systems	Intercommunicating type announcing system
N	Rudder angle indicator system
1PA to 5PA	Auxiliary gun firing systems
PR	Plotting room ready light system
QB	Shell hoist latch indicator system
QC	Powder hoist interlock system
R	Ready light system
RA	Intra turret emergency alarm system
RE	Turret power elevating indicator system
RT	Turret power training indicator system
1U to 5U	Cease firing signal systems
IVB to 5VB	Solar signal systems
XJ	Supplementary telephone system
XGE	Auxiliary main battery control
XJA	Auxiliary battle telephone system
XL	Auxiliary steering telegraph system
X1MB and X2MB	Auxiliary engine order telegraph system
XN	Auxiliary rudder angle indicator system
Y	Underwater log system

TABLE 9-3d
INTERIOR COMMUNICATION AND FIRE CONTROL SYSTEMS

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Cable tags

FIGURE 9-16
TYPICAL CABLE TAGS

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COLOR IDENTIFICATIONS

Power System	Cable Type	Phase or Polarity	Color or Code
3 ph. a.c.	3 cond.	A B C	Black White Red
	2 cond.	AB	A = Black B = White
		BC	B = White C = Black
		AC	A = Black C = White
3 ph. d.c.	3 cond.	+ ± -	Black White Red
	2 cond.	+ and ±	+ Black + White
		± and -	± White - Black
		+ and -	+ Black - White
2-wire d.c.	2 cond.	+ -	Black White

Note 1. - The conductor to be used as the ground conductor, in cables where this is required, in any system, shall be the red conductor in 3-conductor cables and the green conductor in 4-conductor cables.

Note 2. - The ±, or neutral, polarity, when it exists, shall always be identified by the white conductor. This white conductor shall always be connected to the screw shell of lighting unit sockets to reduce to a minimum the shock hazard to personnel.

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COLOR CODE USED IN MARINE ELECTRICAL I. C. and F. C. CABLES NAVY TYPE
Wire No.	Base Color	Tracer Color	Tracer Color
1	Black
2	White
3	Red
4	Green
5	Orange
6	Blue
7	White	Black
8	Red	Black
9	Green	Black
10	Orange	Black
11	Blue	Black
12	Black	White
13	Red	White
14	Green	White
15	Blue	White
16	Black	Red
17	White	Red
18	Orange	Red
19	Blue	Red
20	Red	Green
21	Orange	Green
22	Black	White
23	White	Black	Red
24	Red	Black	White
25	Green	Black	White
26	Orange	Black	White
27	Blue	Black	White
28	Black	Red	Green
29	White	Red	Green
30	Red	Black	Green
31	Green	Black	Orange
32	Orange	Black	Green
33	Blue	White	Orange
34	Black	White	Orange
35	White	Red	Orange
36	Orange	White	Blue
37	White	Red	Blue
38	Brown
39	Brown	Black
40	Brown	White
41	Brown	Red
42	Brown	Green
43	Brown	Orange
44	Brown	Blue

TABLE 9-5
NAVY STANDARD COLOR CODE FOR CONDUCTORS

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SECTION 6

PREPARING FOR INSTALLATION

1. INTRODUCTION. The cable for a piece of equipment has been installed in the wireways and is run to the equipment. The job now is to tie it into the equipment. Assume that the cable is to enter the equipment through a stuffing tube. The first consideration is the proper length of cable; it should be made somewhat longer than just enough to reach the connection point. Form the cable run from the last cable strap to the equipment by hand, allowing for a clean sweep and enough slack at the stuffing tube. This last allowance is for the conductor run inside the equipment; here, good judgment must be used. Determine whether the conductor goes directly to its connection or whether it forms a laced cable and breaks off. Determine the longest conductor run in the laced cable, and add approximately 2 1/2 times this length to the length already determined up to the stuffing tube. This safety factor covers mistakes in attaching lugs or allows for re-routing. It is desirable to have a surplus so as to avoid cable renewals in the event of repairs. In applications where trouble may be anticipated, as in outside submarine wiring, allow approximately four feet additional slack in the cable run to avoid cable renewals, especially where the cable run is long. The cable length is now known and cut. The next step is to remove the armor.		2. REMOVING THE ARMOR. Form the cable as it is to be run into the stuffing tube and carefully estimate where the cable should come through the tube. Mark this position with a piece of friction tape. (Figure 9-17). The tape serves to seize the armor to prevent unraveling and holds down the armor while cutting; in addition, it serves a marker. The actual cutting of the armor may be done with diagonal cutters or with armor strippers. Strippers, when available, are capable of doing a neat, fast job (See tool section), although care must be used in working knife blade adjustments on these tools. Most installation men use diagonal cutters. The quality of the work done with diagonal cutters depends, to a great extent, upon experience; an in-experienced man may easily cut through insulation and spoil a cable. Method of cutting armor is as follows: The cut may be taken either just in front of the tape marker or within it. By cutting just in front of the marker, the worker can closely watch his cut and avoid cutting insulation. The frayed edges of the armor can then be trimmed away. When cutting within the tape marker, the tape serves to hold the frayed edges down, but care must be used to avoid cutting the insulation. The armor is cut around the circumference of the cable (Figure 9-18).

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When the length of armor to be removed is not too great, it may be worked off without further cutting, but in some cases the armor must be cut lengthwise		for easy removal. The important thing to remember in cutting the armor is to avoid cutting the insulation, since this may let the frayed armor edges penetrate the cable and cause grounding.

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Drawing of cable before stripping armor.

FIGURE 9-17
REMOVING ARMOR FROM CABLE

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Using cross cut snips to cut armor.

FIGURE 9-18
REMOVING ARMOR FROM CABLE

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3. STRIPPING INSULATION.

After the armor has been removed, start to remove the insulation at a distance of approximately 1/2 inch from where the armor terminates (Figure 9-19).

The following procedure is recommended in stripping the insulation:

First, if one end of the cable is not secured, place the end in a vise or have another man hold the cable. Put a bend in the cable and carefully ring the insulation (Figure 9-20) taking care to cut only the insulating jacket and not into the insulation of individual conductors. With the knife blade at an angle, start cutting a strip lengthwise, approximately 1/2 inch wide and long enough to allow side cutters a grip on the insulation (Figure

9-21 and 9-22). Pull down on the cut with the side cutters. This will form a 1/2 inch strip, and after stripping approximately 4 inches, the remainder of the strip can usually be removed by hand (Figure 9-23).. It is an easy matter to peel off the remaining insulating jacket and to trim off the filler and threads of insulation with a pair of scissors or diagonal cutters.

The Jones cable stripper may be used to perform all of these operations very efficiently. Detailed instructions on the use of this stripper are included in chapter 3 - Hand Tools. The Huff cable stripper (See Chapter 3) can be used only on lengthwise cuts.

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Cable with armor off showing 1/2inch min of insulation.