June, 1978 A-78-200-754-2

An American-Standard Company

SERVICE MANUAL 543-A

UNION TIME CODE CONTROL SYSTEMS 506~A and 514

CONTROLLED WITH UNION FST CARRIER

UNION SWITCH & SIGNAL DIVISION WESTINGHOUSE AIR BRAKE COMPANY

Swissvale, PA 15218

MANUAL 543-A

UNION TIME CODE CONTROL SYSTEMS 506-A AND 514

CONTROLLED WITH UNION FST CARRIER

GENERAL APPLICATIONS

WRBCC ~

FST Carrier Control makes possible the simultaneous operation of a number of time

code control line circuits over one pair of wires. Consequently, it is employed princi­

pally for large C. T. C. installations where it is desirable to divide the territory into two

or more sections. Ordinarily this would necessitate the use of a separate pair of wires

for each section. However, with Carrier Control all sections can be controlled indepen­

dently from the same control point over one pair of wires. The section adjacent to the

office is usually controlled directly by means of a conventional d. c. code line circuit.

The second section, which is installed as an independent d. c. code line circuit, is con­

trolled by carrier frequencies transmitted over the first section. A third section can

readily be controlled by means of a different pair of carrier frequencies transmitted

over the first and second sections. It is thus apparent that additional sections, if requir­

ed, can be controlled in a similar manner to extend the territory to any desired practic­

able length or to handle any number of functions in a particular territory.

FST Carrier can readily be coordinated with other communication facilities and may

be superimposed on the same wires with other facilities. This very important applica­

tion affords great latitude in locating the control point for a C. T. C. installation. For

example, the desired control point may be far enough from the actual C. T. C. territory

that it might not be considered practicable to extend the wires of the line circuit to that

point. In such an instance, it is usually possible to transmit the carrier over an existing

communication line and thus permit the control point for the C. T. C. territory to be at

the preferred location. This flexibility in choosing the control point has resulted in an

increasing tendency to centralize the control of C. T. C. territories by locating the con­

trol machines at Division Headquarters.

PRINCIPLES OF OPERATION

A typical C. T. C. installation having one conventional d. c. section and two sections

controlled by carrier is illustrated schematically by Figure 1.

543-A, p. 1

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FEATURES OF THE SYSTEM 1. A number of sections may be operated simultan­

eously over a two wire line. 2. Addition of the carrier control equipment re­

quires no change in the standard d. c. code equip­ment.

3. "Union" Coded Carrier Control may be coordinat­ed with existing communication circuits of any kind, including carrier, with proper engineering of the installation.

SCHEMA TIC DIAGRAM ILLUSTRATING APPLICATION OF CODED CARRIER CONTROL TO C. T. C.

4. Coded Carrier Control units are conveniently plug connected, and office and field units are inter­changeable.

5. All units of the standard d. c. code equipment are interchangeable between non-carrier installations and systems employing Coded Carrier Control apparatus.

FIGURE 1

~I

WABCD ~""" The section adjacent to the office (line "A") is installed in the regular manner using

a multiple type Time Code Control system. A filter is installed between each coding unit

(office and field) and the line to prevent the line coding contacts from introducing undesir­

ed high frequency currents on the line, and to prevent the code equipment from shunting

the carrier current circuits and any voice frequency telephone circuits that may be on

the line. Also, a filter is provided between each telephone and the line to prevent faults

which may occur in the telephone from affecting either d. c. codes or coded carrier on

the line. This section thus provides a path over which the direct current, superimposed

carrier and voice frequency currents may flow simultaneously without interference.

The second section (line "B") utilizes all of the elements of the Time Code Control

system and, in addition, is provided with Carrier Control apparatus. The second sec­

tion has its own line battery and is insulated from the near section insofar as d. c. im­

pulses are concerned by a filter which blocks d. c. impulses while maintaining the con­

tinuity of the line for such facilities as voice frequency telephone, carrier communication,

or additional coded carrier circuits which may be superimposed on the line. When such

facilities are superimposeq on line "B 11, suitable filters must be inserted between each

coding unit and the line on the "B II section.

Control codes developed in the office coding unit for line "B II are transmitted over

line "A" in the form of coded impulses of a given carrier frequency, known as the "con­

trol carrier frequency". The field carrier equipment at the remote end of line 11 A11 re­

ceives these coded carrier frequency impulses and converts them to d. c. impulses which

operate the field stations on line 11B II in the conventional manner.

On indication codes the field carrier equipment receives d. c. indication impulses

from the field stations on line 11B" and converts them to coded impulses of a second car­

rier frequency, known as the "indication carrier frequency", which are transmitted to

the office over line "A". The office carrier equipment receives these carrier frequency

impulses and converts them to d. c. impulses which in turn operate the office line coding

unit for line "B".

A remote line unit is required at the field carrier location to polechange the line

543-A, p. 3

WABCO ~

battery during indication codes originating on line "B" and to restore normal polarity at

the end of each indication code.

One or more additional sections can readily be controlled in the manner just describ­

ed, using different carrier frequencies for each section. The component parts for each

additional section would be the same as those shown for line "B". The carrier equipment

provided for each section would respond only to the carrier frequencies employed for that

section.

Detailed Description of Circuits

The basic principles of operation of the 506-A and 514 code systems, when car­

rier controlled, are described below. It should be kept in mind that the circuits shown

and described here are typicals. The circuit for each specific installation should be

used when wiring or trouble shooting a particular installation.

506-A System

The office carrier circuits used in connection with the 506-A system are shown

in Figure 2. On control codes, the transmitter keying relay is alternately energized and

de-energized by contact C3 of the office transmitting relay T thus causing the carrier

transmitter to send the code. (For an explanation of the 506-A code system, see manual

506A.) This circuit may be traced from battery 816 over T (C3) front, PC (B2) back,

terminal 41, back contact of field station disconnect button, terminal FSK on the carrier

terminal and thence to the coil of the keying relay. The keying relay is also energized

normal for a short interval at the 16th step of indication codes, to transmit a short pulse

for restoring the polarity of the carrier controlled section to normal so that field and

office units reset simultaneously to normal. This pick-up circuit is from battery through

R (3N), terminals 56 and 45, front contact of 16 (CS), back contact of T (C6}, back con­

tact of X (83), front contact of PC (BS) and the back contact of the field stations disconnect

button to the keying relay.

When the field stations disconnect (FSD) apparatus is used, there is an additional

energizing circuit for the keying relay through the front contacts of the FSD button. The

keying relay is energized during the entire time that the FSD button is operated. This

action de-energizes the d. c. line circuit in the field.

543-A, p. 4

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Figure 2. Office Carrier Circuits for 506-A System

543-A, p. 5

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Figure 3. Office Carrier Circuits for 514 System

543-A, p. 6

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Relay C functions only during indication codes. The indication carrier pulses

received cause relay C to be operated normal and reverse alternately. Contacts lN and

2R of relay C in turn apply energy pulses to the coil of relay R in the office line coding

unit in accordance with the indication code being received. Relay R thus follows the action

of the transmitting relay at the indicating field station.

514 System

The office carrier circuits used in connection with the 514 system are shown in

Figure 3. On control codes the keying relay is alternately energized and de-energized

by front contact of lT (C3) thus causing the carrier transmitter to send the code. (For

an explanation of the 514 code system, see manual 514.) This circuit may be traced

from 816 to terminal 200, front contact of lT (C3), back contact of PC (B2), terminal 210

and terminal FSK on the carrier panel to the keying relay. The keying relay is also ener­

gized for a short interval at the beginning of the last step of indication codes to transmit

a pulse for restoring the polarity of the carrier controlled section to normal so that field

and office units reset simultaneously. This pick-up circuit for the keying relay is from

battery on R (3P) over R (3N), terminal post 30, front contact of CS (C3), terminals 190

and 180, back contact of lT (C6), front contact of PC (BS), terminal 210 to the keying

relay.

Relay C functions only during indication codes. The indication carrier pulses

received cause relay C to be operated normal and reverse alternately. Contacts lN and

2R of relay C in turn apply pulses of energy to the top coil of the office line relay R.

Relay R thus follows the action of the 1 T relay at the indicating field station.

Figure 4. Remote Line Unit

543-A, p. 7

WABCC ~

FIELD CARRIER CIRCUITS AND REMOTE LINE UNIT

The circuits for a field carrier location are shown in Figure 7. The equipment is

the same for both 506-A and 514 systems.

Relays C and RL shown in Figure 7 are stick-type KP relays. Relays PC, PCP, NPCP,

NPCPP, and NSA are Style L relays and are mounted in a plug-connected unit known as the

remote line unit. The KP relays are associated directly with the transmission and recep­

tion of carrier codes, whereas the L relays are associated with the pole changing of the

d. c. line, the stabilization of relay RL during control codes, and the eventual local re­

storing of normal polarity to the carrier controlled section even though no carrier reset

pulse is received from the office.

On control codes, the contacts of relay C follow the carrier received from the office

and in turn apply corresponding d. c. pulses to the carrier controlled section; contact 2R

opens and closes the line battery circuit, and contact lN shunts the line to bleed off the

electrostatic charge on the line. The 0. 25 mfd capacitor between terminals 11 and 16 of

the remote line unit acts as a suppressor of the arcing at the C relay contacts. Relay

PC remains released during control codes to maintain normal polarity on the carrier

controlled line. Relay RL does not operate during control codes, and relays PCP and

NPCPP establish circuits to stabilize its position during these codes. On the first step

of a control code, relay PCP picks up over contact 3N of relay C, closing the pick-up

circuit for relay NPCP which energizes in turn its repeater relay NPCPP. When relay

PCP picks up, it estali>lishes a shunt circuit across the secondary winding of the impulse

transformer to prevent impulses from being delivered to relay RL as the control code

progresses. This shunt is also beneficial to code transmission because it reduces the

inductive effects of the transformer. The shunt circuit is over back contact Bl of relay

PC and front contact C3 of relay PCP which is in multiple with front contact C3 of relay

NPCPP. Relay PCP may release on some of the long steps of control codes, but the shunt

circuit is retained by front contact C3 of relay NPCPP which does not release until the

reset period of the code is reached. At the same time, the lower winding of relay RL is

energized in such a direction as to maintain relay RL in the position shown. This circuit

543-A, p. 8

WABCO "-,/'~

may be traced from battery mid-tap to the lower winding of relay RL and thence over

back contact Cl of relay PC and front contact A3 of relay NPCPP to negative battery (Nl6)

at terminal 20 of the remote line unit.

On indication codes, relay RL responds to the shunting of the line by the field station

and operates the keying relay which transmits the code to the office. When the line is

shunted at the beginning of the first step of an indication code, relay RL receives an im­

pulse from the secondary of the impulse transformer. This impulse operates relay RL

to its reverse position, and contact 4R of relay RL causes relay PC to pick up. Relay

PCP is then energized over contact 2R of relay RL and front contact AS of relay PC.

Front contact A3 of relay PCP closes the pick-up circuit for relay NPCP which in turn

energizes its repeater relay NPCPP. Front contact A3 of relay NPCP provides a stick

circuit for relay PC so that relay PC is not affected by subsequent operations of relay

RL during the remainder of the code. When relay PC picked up, its front contacts BS

and CS pole changed the line circuit. At the same time, front contact Bl of relay PC in

series with back contact A4 of relay NPCP established a shunt circuit across the second­

ary winding of the impulse transformer to prevent relay RL from receiving any undesired

impulses while the line circuit is being pole changed. Also, front contact Cl of relay PC

in series with back contact C4 of relay NPCP and back contact C4 of relay NPCPP com -

pletes a holding circuit for RL through the lower winding of the relay. These stabilizing

circuits are in effect during the interval between the pick-up of relays PC and NPCP, to

hold relay RL in its reverse position during the time the ct. c. line is being pole changed

and for an additional interval to permit the line current to become stabilized. This oc.­

curs before the end of the first step. At the end of the first step of the code, the trans­

mitting station removes the shunt from the line and relay RL is operated to its normal

position.

Throughout the main portion of the indication code, relay RL responds to the impulses

on the ct. c. line, going reverse when shunts are applied and normal when shunts are re­

moved, and in turn causes the indication carrier to transmit the codes to the office.

During the reset period of an indication code (after office relay 16 or CS picks up and

543-A, p. 9

WABCO ~

before office relay PC releases with office line relay normal), an impulse of control car­

rier frequency will, under normal circumstances, be received from the office. This

pulse of control carrier operates relay C to its normal position just long enough to open

the stick circuit for relay PC at contact 4R of relay C. Relay PC releases and restores

normal polarity to the d. c. line circuit. Therefore, the office and field units reset in

step with their line relays normal. Stabilizing circuits are again provided to prevent

relay RL from receiving undesired impulses while the line is being pole changed back to

normal. A holding circuit through the lower winding of relay RL is provided over back

contact Cl of relay PC and front contact A3 of relay NPCPP. At the same time, the sec­

ondary winding of the impulse transformer is shunted by back contact Bl of relay PC and

front contact C3 of relay NPCPP. These stabilizing circuits are maintained during the

interval between the release of relay PC and the release of relay NPCPP.

If, for any reason, such as being blanked by a severe lightning surge, the reset

pulse is not received during the reset period of an indication code, the field carrier

equipment will reset to normal automatically after a predetermined time interval. In

such an instance, the pick-up circuits for relay PCP will be open at contacts 3N of relay

C and 2R of relay RL, since relay C will not have been operated to its normal position

by a pulse from the office and relay RL will have operated to its normal position when

the last shunt was removed from the line by the indicating field station. Relay PCP will

release, causing relay NPCP to release. Relay NPCP opens the stick circuit of relay PC

and de-energizes relay NPCPP. Relay PC releases immediately and pole changes the d. c.

line circuit. During the interval between the release of relay PC and the release of slow

release relay NPCPP, the stabilizing circuits for relay RL described in the preceding

paragraph are established to prevent undesired operations of relay RL.

In the event relay RL remains steadily in its reverse position, the circuit will also

function to establish normal polarity on the d. c. line circuit. In this instance, NSA is

the first relay to release, opening the pick-up circuit of relay PC and de-energizing re­

lay NPCP. The release of relay NPCP opens the stick circuit of relay PC which releases

promptly. Relay NPCPP is de-energized by the opening of contact C3 of relay NPCP.

543-A, p. 10

WABCD

~·~ Note the shunting of the secondary winding of the impulse transformer over back contact

Bl of relay PC and a front contact C3 of relay NPCPP. Other contacts of these same re­

lays establish a circuit to operate relay RL normal through its lower winding.

SYNCHRONIZING CIRCUITS

On a carrier system, a disturbance on the line, such as a severe lightning surge,

may stall or blank out a step of an indication code and cause the office and field units to

get out of step. To reset the office and field units together under these circumstances,

synchronizing circuits are provided in the office carrier circuits.

Assume that a severe line disturbance during an indication code causes relay C to

operate, thereby opening the remote line and prematurely releasing relay PC in the re­

mote line unit at the field carrier location. PC releasing will position relay RL normal,

cutting off carrier current to the office and operating relay R in the office to its normal

position with relay PC in the office coding unit still picked up. Once the line disturbance

has ceased, relay C recloses the remote line circuit and positions some of the field line

relays normal. Those stations that might have been indicating will have their M relays

energized and will now be pole changed with respect to the line. The line relays atthose

field stations more remote than the indicating stations will pick up only after the shunts

are removed at the stations that were indicating. Those ahead of these stations will have

their line relays up.

Thus, the office line relay is normal, the timing relays in the office have started to

reset, and relay PC in the office is still picked up. Some of the field line relays are up

and are resetting simultaneously with the office. Some of the field line relays are behind

in picking up the line relays. The remainder will stay down until their M relays release.

The field carrier equipment is ready to receive control codes since relay PC is released

at the field carrier location, but some of the field stations are not yet ready to receive

them. Therefore, all line relays must be brought into synchronism before the units in

both office and field reset completely. The first step is to drop all line relays to agree

with those that are already down in the field, and hold them released until all units have

had time to reset. The second step is to pick up all line relays simultaneously, including

543-A, p. 11

WABCD ~

operating the one in the office normal, and have the units reset normal ready for coding.

The action of the synchronizing circuits for accomplishing this is as follows:

S06-A System

Relay RS provides the means for accomplishing the synchronizing in this system.

When relay R in the office stays normal with relay PC up ( 16 has not yet been energized),

the timing relays 2L, LP, LB, and LBP drop out. A circuit from positive battery over

the 30-ohm resistor, front contact C3 of relay PCP, back contact CS of relay 2L, back

contact CS of relay LBP, terminal 62, relay RS, terminal 61, front contact B2 of relay

PCP, front contact A2 of relay PC, back contact CS of relay X, back contact C3 of relay

M, back contact B3 of relay T and 33-ohm coil of relay R to battery mid-tap energizes

relays RS and R reverse. Relay RS locks relay R reverse and energizes the keying re­

lay, causing a character to be transmitted to the field to operate relay C normal. This

de-energizes the carrier controlled line and releases all field line relays. When relay

R in the office goes reverse, the timing relays pick up, and then start dropping out since

relay R stays reverse. Relay 2L remains picked up for the same reason. When relay

LBP releases with relay 2L up, relays RS and R are energized normal, over battery mid­

tap, 33-ohm coil of relay R, back contact B3 of relay T, C3 of relay M, CS of relay X,

front contacts A2 of relay PC, B2 of relay PCP, terminal 61, relay RS, terminal 62, back

contact CS of relay LBP, front contact CS of relay 2L, back contact AS of relay lL, and

30 ohm resistor to negative battery. This unlocks relay R, allowing it to go normal.

The keying relay is de-energized restoring the carrier circuit to normal. Consequently,

relay C closes its reverse contacts and re-energizes the carrier controlled line. All

field line relays pick up, and all office and field units reset simultaneously. When office

relay R goes normal with relay LBP down, relay PC in the office releases, thereby open­

ing the circuit for sending relay R back to reverse.

Relay PCS is provided to insure that the office and field units reset together in

the event that a code is stalled with the office line relay normal. Without PCS, the key­

ing relay would be energized and would send a pulse of carrier energy to the field for the

full duration of the PCP release time. Since the release time of relay PCP is necessarily

543-A, p. 12

long, for the purpose of stabilizing the circuits on the secondary of the impulse trans­

former on a conventional d. c. line, this impulse would last so long that the field units

would get behind the office in resetting.

Relay PCS is placed in the circuit so that it is energized in multiple with the key­

ing relay and its back contact C4 is in series with the keying relay circuit. In the event

of an incomplete code, relay PCS picks up immediately after the keying relay and cuts

short the carrier impulse to the field so that the field units will reset at the same time

as the office coding unit. The multiple pick-up circuit for PCS and the keying relay is:

positive battery over contact R (3N), back contacts of 16 (CS) and X (AS), front contact

of PCP (CS), back contact of PC (C2), then over one multiple path through the coil of re­

lay PCS to negative battery. The other multiple path is through back contact of PCS (B4),

back contact of T (C3), back contact of PC (B2), through the coil of the keying relay to

negative battery.

Relay PCS is also picked up during control codes to eliminate the snubbing action

of the keying relay in case there is a voltage drop in the negative battery wiring between

the PCS and keying relays.

514 System

Relay XS provides the means for accomplishing the synchronizing in this sys­

tem. When relay R in the office stays normal with relay PC up (CS has not yet been ener­

gized), the timing relays 2L, LP, LB and LBP drop out. When LBP releases, PC is de­

energized and released. A pick-up circuit for relay XS is closed over back contact of

PC (C6), PCP (BS), IL (C7), back contact of LBP (D6) and 2L (Bl) to the coil of XS.

Relay XS up energizes relay IT over XS (C3), back contact of M (C3), and back

contact of 2T (B3) to the 1 T coil. 1 T up keys the carrier and causes the line circuit in

the field to become de-energized over previously described circuits. 1 T up also reverses

the office line relay (contact AS). Thus the office and all field units are in agreement.

The office R relay going reverse causes the timing relays 2L, LP, LB and LBP

to pick up as well as relay PC. When LBP picks up, XS is held up over its own front

543-A, p. 13

WABCC ~

contact A3 and front contact of LBP (06). The unit (along with all field units) now goes

through a reverse drop-out during which relays IL, LP, LB and LBP release. When LBP

releases, XS is de-energized and releases.

XS releasing removes the battery from relay 1 T and it releases. This results

in all line relays returning to their normal (picked up) positions. The circuit for the

office R relay is negative battery through a 30-ohm resistor, PCP (A7), back contact of

PC (C2), back contact of M (C6), back contact of IT (AS) and the lower coil of the R re­

lay. With R normal and LBP down, relay PC releases.

When relay PC releases, it de-energizes PCP which, after a time interval, will

release. All units, office and field, reset normal and are ready to code.

TWO-WAY REMOTE LINE UNIT

The circuits for a two-way remote line unit used for the purpose of operating two

separate sections of line are shown in Figure 8. The carrier equipment itself is similar

to that used at regular field carrier locations. There is a repeater relay C 1 that follows

the control code pulses. Contacts 1 and 4 of this relay code the two d. c. line sections in

the usual manner. Relay PCP and its repeater relays NPCP and NPCPP pick up on control

codes, placing a shunt on the secondary winding of each of the impulse transformers.

These shunts are established over the usual disagreement circuit between relay PC and

relays PCP and NPCPP. A circuit for stabilizing the RL relay for each line during con­

trol codes is provided. The stabilizing circuit for relay RL may be traced from the lower

coil of relay RL through back contact Bl of relay PC, front contact A3 of relay NPCPP,

and a 15-ohm resistor to negative battery (Nl6). A similar circuit for relay RL-1 may

be traced from the lower coil of relay RL-1 through back contact Bl of relay PC-1, front

contact 86 of relay NPCPP, and a 15-ohm resistor to negative battery (Nl6). The action

of these circuits is the same as that of the circuits of the standard remote line unit. It

is thus obvious that control codes coming in over the carrier circuit will result in cor­

responding d. c. pulses being delivered to each of the d. c. line circuits.

A pole changing relay (PC or PC-1) is provided for each d. c. line circuit. Assume

an indication code to originate on the right-hand (east) line circuit. Relay RL will move

543-A, p. 14

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to its reverse position, energizing relay PC over contact 4R. Relay PC then sticks up

under control of contact 3R of relay Cl, and is not affected by the following operations

of relay RL. This pole changing of the line circuit locks out all other field stations on

the same line and, as will be seen later, prevents the field stations on the left- hand line

circuit from transmitting. Contact 3N of relay RL will then code the indication carrier

and thus transmit the code to the office. Back contact D2 of relay PC is in series with

the line battery circuit for the d. c. line circuit on the left. During the time that an in­

dication code is being transmitted by a field station on the line circuit to the right, the

line circuit to the left is held open at the back contact D2 of relay PC, preventing trans­

mission of indication codes by any field station on the line circuit to the left.

In a similar manner, ind,ication codes originating on the line circuit to the left (west)

will operate relay RL-1 which in turn will energize pole changing relay PC-1. Back con­

tact D2 of relay PC-1 is in series with the line battery circuit for the d. c. line circuit

on the right. Therefore, during the time that a field station on the line to the left is

transmitting an indication code, field stations on the line to the right are prevented from

transmitting.

In the event that field stations on both lines start to transmit indication codes at the

same time, both pole changing relays may pick up, but relay PC-1 is given preference

and relay PC releases promptly following the pick-up of relay PC-1. This preference is

established by back contact D6 of relay PC-1 which is in series with the pick-up and stick

circuits of relay PC. It is evident that this preference may readily be given to either line

as desired.

MAINTENANCE OF REMOTE LINE UNITS AND ASSOCIATED APPARATUS

General

It is recommended that field maintenance tests as outlined below be made at

regular intervals of three months during the first year and at intervals of six months

thereafter.

Since traffic conditions vary so widely on different installations, no specific re­

shopping schedule can be generally applicable. However, the auxiliary equipment should

543-A, p. 15

WABCO

~·"""' be brought into the shop after the first one or two years of service and given a detailed

check and inspection.

The condition of the units as shown by the first shop inspection will enable rail­

road maintenance personnel to set up a suitable re-shopping schedule.

Field Maintenance Tests

The operating condition of the auxiliary equipment can be determined in service

by making timing checks of control and indication codes as described under the Field

Maintenance Tests section of the Time Code Control system maintenance manual apply­

ing to the installation (U-5122 for 506-A and U-5138 for 514).

Satisfactory results on the code timing checks indicate that the auxiliary equip­

ment as well as the coding apparatus is operating properly.

In the event that the "in service" timing is not within the limits specified, the

faulty equipment can best be detected by placing spare equipment, known to be in good

condition, in service one unit at a time and repeating the timing checks after each re­

placement. The nature of the timing discrepancies will very probably be of considerable

aid in determining which equipment may be at fault.

Re-shopping Remote Line Units

The following procedure is recommended for re-shopping remote line units.

The inspections and tests should be made in the order listed.

l. Inspect wiring of equipment and top plate for evidence of heating and

lightning shots. Test insulation of relay contact stacks involved in the line circuit,

using an instrument that applies at least 100 volts between the contact members and the

relay frame. A 500-volt megger is a suitable instrument for this purpose. In the tests

below, readings in excess of 200 megohms :should be obtained.

Insulation tests may be made by meggering between the following terminal posts

on units which have been removed from service. A more detailed check should be made

inside the unit when the megger tests indicate the presence of damaged insulations. In­

sulated bushings and blocks which give a megger reading of zero or nearly zero should

543-A, p. 16

WABCCI ~

be replaced. (The resistance of such damaged insulations when measured with instru­

ments other than the megger, may be as high as 3000 or 4000 ohms.

One- Way Remote 17 to 1, 2, 6, 7, 10, 12, 13, 18, 19, 20, case Line Unit Pc. UN255172

18 to 3, 6, 7, 10, 12, 13, 19, 20, case

Two-Way Remote 7 to 2, 8, 10, 11, 12, 17, 18, 19, 20, 25, 26, 27, 31, Line Unit Pc. UN271178 32, case

8 to 10, 11, 12, 17, 18, 19, 20, 25, 26, 27, 31, 32, case

31 to 10, 11, 12, 17, 18, 19, 20, 25, 26, 27, case

32 to 10, 11, 12, 17, 18, 19, 20, 25, 26, 27, case

2. Inspect all connections for tightness and proper soldering.

3. Inspect mounting of equipment and mounting strips for tightness.

4. Inspect relay contact stacks to determine whether any are loose.

5. Inspect and clean relay armatures, cores, and backstraps in accordance

with Service Specification SU-3701 for Style "L" relays.

6. Inspect the relays for burned or pitted contacts and check contact adjust­

ment. With the exception of the contacts listed below, it is not necessary to accurately

gauge and adjust each contact. On each relay, one contact which meets the values speci­

fied in Service Spec. SU-3701 may be used as a guide in making a visual comparative

check of the adjustments of the remaining contacts. Each of the contacts listed below

should be accurately gauged and adjusted. See wiring diagrams for piece numbers of

these relays.

One-Way Remote Line Unit Pc. UN255172

PC relay, contacts Bl.and Cl

Two- Way Remote Line Unit Pc. UN27 l l 78

PC relay, contacts Bl and Cl

PC-1 relay, contacts Bl and Cl

Relay contact stacks are numbered A-B-C-D-E from left to right facing front of

relay which in the type "L" relay is the armature end. If a space for a stack is left va-

543-A, 1?• 17

WABCD ~~

cant, the space is lettered as if the stack were present. Contact spring members are

counted from top to bottom, only members appearing in the stack being counted. Coil

connectors are counted as a contact member, unless they are in the same space with

the contact.

7. Check relay calibrations and re-calibrate when necessary in accordance

with Service Spec. SU-3701.

8. Time the relays in the unit using the cycle recorder connected as indi­

cated in the timing table at the back of this pamphlet (Figure 6). Follow the instructions

given in the table for timing the individual relays. For example, to time the PCP relay -­

a. Connect positive 16 volt battery to one pole of the double-pole snap

switch and the other pole to one side of 110 volts a. c. (A snap switch should be used to

insure correct timing values·.)

b. Connect the first point of the switch to post 10 on the remote line

unit and the second point to post R on the cycle recorder.

c. Connect post 2 of the line unit to post N of the cycle recorder.

d. Connect the same side of the a. c. as was connected to one pole of

the switch (paragraph "a" above) to post 1 on the line unit.

e. Connect the other side of the a. c. to post CX on the cycle recorder.

f. Connect the common or negative side of the 16-volt battery to post

20 on the line unit.

g. Then close the snap switch.

h. Start the cycle recorder.

i. Open the switch and obtain the timing of the PCP release in accord­

ance with the information given in the timing table.

9. Make relay timing adjustments 1 when necessary, in accordance with

Service Spec. SU-3701. If a relay is re-timed, the electrical calibration of the relay

should be re-checked. In the event that a relay does not meet calibration limits after

being re-timed, an effort should be made to adjust it to meet both timing and calibration

limits. Should this prove to be impossible, the relay should be adjusted to meet the tim-

543-A, p. 18

WA&CC ~

ing limits, as timing is the more important factor from the standpoint of satisfactory

operation.

10. Replace and seal the front and back covers on the unit.

KP and P-4 Relays

On standard installations, relays C and RL are Style KP relays and should be

calibrated and re-adjusted, when necessary, in accordance with instructions provided

in Service Spec. SU-3623. On installations where greater sensitivity to line current

change is required of the RL relay than can be obtained with the Style KP relay, the more

sensitive Style P-4 relay may be used. The Style P-4 relay should be calibrated and re­

adjusted, when necessary, in accordance with Instruction Pamphlet U-5447.

KP relays have their .contacts numbered as shown in Figure 5.

On those KP relays which have independent contacts, 1 and 3 are normal contacts

while 2 and 4 are reverse contacts.

(1H)IP--­

+1--t-....--

+2-J.. ....... .,

(4H)O-I-......... _.

(4B)4R_..._,_..,

KP RELAY

C.ONTAC.T NUMBERING VIEWED FROM FRONT

2R(2B)

,.. -- --2N

2P(2H)

-1

-z 3P(3H)

--3R

3N(3f)

KP RELAY AS SHOWN ON CIRCUIT PLAN

+1::B=-1 +2 -2

-i=.IP STIC.K SYMBOL

IN IR

-i=.ZP 2N -ZR

+1::E}::-1 +2 -2

IF--µ-IH

/ZH BIASED SYMBOL

28

38--µ-3H

/4H

411

Figure 5. KP Relay Contact Numbering

543-A, p. 19

l J

1

' ·J j

WABCC ~

Relay Nomenclature

Connections To Cycle Recorder

And Remote Line Unit

Timing Procedure

Relay Release

Time

Relay Nomenclature

Connections To Cycle RPcorder

And Remote Line Unit

Timing Pr:Jcedure

Relay Release

Time

TWO-WAY REMOTE LINE UNIT PC. UN271178

PC PC-1 • PCP *NPCPP *NPCP NSA

Bl6~o---{] 12 Bl6 >-::X:-° 12 .._rg27 BIS~o---{]9 BX 110 --------0 R

cg1s B16ci 12 BXllO --------0 R

~~o 19 BXllO ~R

~~7 ~~o BXll0>-017 BXll0>--019

~~o BXll0>--025

"C "C cx110--®cx BXll0>-019 CXllO--®CX E " .. CXllO--®cx ·; ; C!6+-{]26

B16>1]f

Cl6--026 O' i 816>-025 " 16 a: a:

C16--026 0 0 25 z z

C!6+-{]26 .. .. c c

cx110--®cx ·e ·e i'.: i'.: Open switch, read left hand

Open switch, read left hand Open sw Itch, read left hat'ld Open switch, read left hand recorder punch from time recorder punch from time recorder punch from time right hand punch stops.

recorder punch. right hand punch stops. right hand punch stops.

As Measured As Measured Time Measured Less

As Measured l 9c2 l Cycles 12-14 Cycles

NPCPP Release Time. 24-26 Cycles

14-16 Cycles

ONE-WAY REMOTE LINE UNIT PC. UN255172

PC 'PCP 'NPCPP 'NPCP NSA

B16 ~---010 BXllO ~R

B16~--019 BXllO o--@R

Bl6~--024 BXllO ---® R

B16~--0 6

BXllO ---® R

~~ ~~5 ~~· ~!4 "C

BXllO >-01 BXll0>-03 BXll0>-03 BX!l0>--0 19 i:: ·; CX!lO ~ex CX!lO~CX CXllO~CIC CXllO~ ex O' <I.> C16 --020 Cl6--020 Cl6--0 io C16--0 20 a: 0 B16~10 816~ 10 z bJl 24 19 c: ·e Open switch, read left hand Open switch, read left hand Open switch, read left hand Open switch, read left hand i'.: recorder punch from time recorder punch from time recorder punch from time recorder punch from time

right hand punch stops. right hand punch stops. right.hand punch stops. right hand punch stops.

As Measured 19-21 Cycles

TEST CONDITIONS

D.C. Voltage = 16-18 Volts Temperature - 70° F. Approximately

SYMBOLS

As Measured 12-14 Cycles

O Terminal on Remote Lme Unit Top Plate.

® Terminal on Cycle Recorder

Time Measured Less NPCPP Release Time

14-16 Cycles

Caution: - When timing relays, the Style KP relay which is an integral part of the Recorder should be removed from its plug connector.

To insure proper timing, the double-pole single­throw switch should be snap action type.

• Release Times of the individual relays should be within the specified limits, but the sum of the release times of the PCP, NPCP and NPCPP relays should not exceed 45 cycles.

FIGURE 6

As Measured 24-26 Cycles

TIMING TABLES FOR REMOTE LINE UNIT RELAYS Timing of Relays in Unit, Using Cycle Recorder - Timing in Cycles (60 Cycles= 1 second)

543-A, p. 20

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1-0

N I-'

LI LI

FROM OFFICE L2 L2

TO f'IELD STA.TIONS

L 1 T &::::::oR ,If 2T I JL2 R I - l RL 818

BIS 816Q FSK

i------ RL _____ I i - Nl6 i i '" ... . I

NII NI&! I ~L~ I _ _J

FST CARRIER TERMINAL

! ,, "" """ . ! I C4 23 I PC ~ 6

19

I NPCP~P I L A3 .. o--..!!!! I ---------- -~-~ 3

BIS C4P

4R C4R C3P

~

0 ..... TERMINAL ON CARRIER RELAY PANEL.

0 . .... TERMINAL ON REMOTE LINE UNIT. C3N

816

17

MILLI­AMMETER

PROTECTIVE RESISTOR

PCP NSA~3f C3 24

~~~rr:·~-~~~~~-~~

0

FIGURE 7. Field Carrier Circuits for 506-A ( 506 & 506C) and 514 Systems Using Standard Remote Line Unit.

NI&

PROTECTIVE RESISTOR

,1 ~8

U1 ti::. w I ~

'O

N N

7

MILLI­AMMETER

PROTECTIVE RESISTOR

TO FIELD STATION5 (WEST)

PC-1 PC-1 _ es.--....... ./9CS _

40

816 25 NPCPP NPCP

~• 26 1s• I NPCPP

~~B~&.,__~~~~-z

u-w

L2-W

8

I

I

PC-1 A18 Cl 510..,

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NPCP

.. 818

RL-1

LI L1-E

FROM OFF ICE L2

LIT L1R L2T L2R 31 32

e,61

- l RL-1 RL 816

BIO FSK~ 0

NIO N16 I GNDI c

ri lli1 I 20

816 100w C2P C

~ 22

2R ,.:..c_g_R

I c:\ L L.: _ _J

FST CARRIER TERMINAL

C1

JR RL

PC

A~~i~~R(;'.

PROTECTIVE RESISTOR

19

NP;f P 25 BIO

~· ,-----" NPCPP 5 15°' -_, Al r---0-,./\/

PC 510MJ

20

~l I

I I 4R l4 NSA

C3• '. I ,c-, LI "'""lJ

21 N18 g ~

13 NPCP NII : ~

,2

RL

•2R CJ ~

816 IN

25

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FIGURE 8. Field Carrier Circuits for 506A ( 506 & 506C) and 514 Systems Using Special Remote Line Unit Used to Operate Two Line Circuits.

PROTECTIVE RESISTOR

~I

WABCCJ

An American-Standard Company

UNION SWITCH & SIGNAL DIVISION WESTINGHOUSE AIR BRAKE COMPANY

Swissvale, PA 15218

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