Relay & Electronic Interlocking Design

Chapter 21: Relay & Electronic Interlocking

Section 1: Design Criteria of Signalling Circuits

Circuits - General

• Detailed interlocking circuit designs may be necessary for route setting based on the Entry/Exit principle, with the point having an individual setting for existing setup or modification.
• Non-route setting can have route set with individual point operations for existing setups or changes.
• Designs must align with Chapter 22 of SEM for "Requirements of signalling in 25 KV AC electrified areas".
• Designs should adhere to approved plans, control tables/panel diagrams, relay contact analysis, and rack arrangements.
• Designs must fit specific equipment types like Electronic Interlocking (Distributed or Central), MSDAC, or UFSBI.
• Designs also need to account for interfacing types and features.
• Using dual OFC in distributed systems is preferred to cut down on copper cables and provide safety redundancy. Dual OFC reduces copper cables and failures.
• Drawings and designs should follow typical templates, RDSO standards, guidelines and industry best practices.
• Reliability, availability, maintenance, and safety are key concerns for any design. Designs should be in accordance with Typical templates, RDSO`s Standard circuits/templates, guidelines, Industry's best practices & principles of Reliability, Availability, Maintenance & Safety in mind.

Control Panels-General

• The control panel's illuminated layout display should be well-proportioned.
• The domino-type panel should be used if there are likely to facilities.
• Different colors assist to distinguish track circuits in the covered areas. Different colours clearly distinguish each track circuit's areas.
• Route, point switches/buttons should be provided on the illuminated diagram in geographical order.
• Options include a separate diagram and console for indication and operation. May come with a geographically ordered illuminated diagram or a console containing all operating members
• Routes can be set with individual point operation at Non-route setting type installations. At Non-route setting type installations, the route may be set with individual operation of points.
• Route setting shall follow the "Entry/Exit" principle for Route Setting type, controlled by two push buttons at the route's entrance and exit. The Route setting shall be on "Entry/Exit" principle for installations of Route Setting type. Each route shall be controlled by means of two push buttons-one at the entrance and the other at the exit of the route.
• Signals in Non-route setting may be cleared via a push button with a group button, an individual signal switch, a master switch, etc. after routes by individual operation of points is completed.
• Each point can be operated using an individual push button plus a common one, or two or three-position switches. Individual push button in conjunction with a common push button or two/three position switches shall be provided for individual operation of points.
• If a route has varying overlaps, the desired overlap beyond the exit signal must be selectable.
• Alternate approach routes lets the desired route be set with the desired overlap. Where the route has alternate approach routes, must be possible to select/set it with the desired overlap.
• The switches/buttons should be color-coded for easy recognition.
• Running signals are red, shunt signals yellow, calling on signals feature red with a white dot, and exit buttons white.
• Alternate overlaps have white with a black dot, alternate routes are Grey, points black, slots green, crank handles blue, and point group buttons black with a red dot.

Control Panel Provisions

• Individual point operations must have an arrangement for individual point operation.
• Emergency point operations (during point zone track circuit failures) need to be recorded on a counter. For emergency point operations, where point zone track circuit failures, each individual operation shall be recorded on a counter.
• Slotting features between neighboring cabins, ground-frames, level crossings, and crank handles are a necessity. Necessary slotting facilities for adjoining cabins, ground-frames, level crossings and crank handles etc.
• The slot must be controllable via operation of two buttons or a switch akin to route setting. Arrangement so that slot shall be controlled by operation of two buttons or a switch similar to route setting principle for individual line.
• Group slot cancellation buttons are to be paired with entrance/exit buttons for slot cancellations. Group slot cancellation button to be operated along with entrance/exit button is needed when cancelling.
• Each cancellation withdraws the slot while securing the route for a set time or until route locking is effective. When cancellation happens, it allows the route to be held as time or the mechanism requires.
• Keep track of each slot cancellation event. Each slot cancellation shall be recorded in a counter.
• Removing the Station Master's, SM, key should freeze all signaling gear positions from the control panel but it must allow for setting signals to 'ON' without changing the route. When SM's key is taken out, it shall not be possible to change last operated position of any signalling gear from control panel; facility shall available to put back the signal to 'ON' without altering the route.
• A reinserted SM key must not trigger automatic commands. No command gets executed automatically on reinsertion of SM's key.
• An display indication on the yard and important indications for maintenance staff. An indication panel shall be provided in major yards, giving position of the yard and important indications for maintenance staff.

Indications on Control Panel

• Points are indicated by white/yellow or green lights at each switch, plus white strips on the point zone.
• During point operation, the light/strip for the target position flashes until fully set and locked. Light/strip light shows the intended points will flash until their is correct setting.
• A small white light near the switch/button indicates when a point is locked in a route; it turns off when the point is free. The point locked indication will be the point switch's small, white light near that is extinguished when the point is free.
• Route setting and locking are indicated by route indication lamps and at least two white lights show that each track section is set.
• Lamps go off for routes not set.
• Activating a route correctly lights it with a row of white lights. The complete route over which movement is to occur displays white lighting.
• A train moving across a route changes the occupied section to red and once cleared turns these back to white until the route is released. As the train moves over the route, the occupied portion shall light in red.
• Red indicates a stop signal at 'ON'; yellow indicates a permissive signal at 'ON' on the control panel.
• Green, yellow, or double yellow indicates the field signal is 'OFF'
• In domino panels without indication of all aspects, green signifies any OFF aspect, accompanied by flashes according to conditions:
  • Green flashes red signify failure of green
  • Green flashes red means failure of yellow.
  • Green and red flash means failure of double yellow.
  • Green not lit (blank), red flashes mean failure of red and yellow is for permissive signals.
• No indication is needed for a shunt signal's 'ON' aspect on the same post as the running signal but independent shunt signals 'ON' state shows with a white light strip or two miniature lights horizontally.
• 'OFF' aspect for a shunt signal will display via a slanting white light strip or two miniature slanting lights and such is positioned below the running signal indication if the shunt signal is on the same post as a running signal.
• 'A'/'AG' marker should light up with white light for automatic operations set on the control panel.
• "Calling on" signal indications displays a white light. The "Calling on" signal is 'OFF' with white light.
• A lit white strip light is present along with the running signal symbol when repeater of a Starter Indicator shows it's 'OFF' aspect.
• Occupied tracks display a row of, at least two, red lights on each track circuit portion and the red lights go off when tracks are clear.
• Mains/Diesel Generator/Catenary supply sources are indicated with a suitable indication.
• The indications are omitted if there is a Change over Panel in SM room.
• Approach track circuits are placed on the illuminated layouts and in continuous track circuit territory, these will cover all track circuits behind the first stop signal up to either the next signal or a track circuit specified.
• Tracks controlling calling on signals are marked distinctly.
• Anticipated train warnings are indicated via flashing lights or an audible alarm to alert the Station Master.
• These warnings are discontinued upon track occupancy or train signal changes.
• The audible warning can be silenced with a button but reactivates for subsequent trains.
• Signal Lamp Failure: A red light and accompanying sound alerts to signal aspect/route failures.
  • The group of signals may have specific and common alerts.

Control panel indications

• The cancelling of audio doesn't impact incoming trains.
• Displays on the panel show when crank handles are locked/unlocked, with the following rules-
  • Indicate the difference locked or free of each crank with different aspects.
  • Locking mechanisms feature a steady yellow light if the crank handle is steady
  • Locking mechanisms feature a steady yellow light steady if the crank handle is inserted/locked. when CH key is in & locked - Yellow Steady
  • If the signal for CH is extracted without taking back its CH control features with a red flash. CH key released from control panel but CH key is not extracted/When CH key is inserted back but CH control is not, Red Flashing,
  • A CH key released and extracted shows a steady red light. When CH key released and CH key extracted - Red Steady
• The timer flashes yellow if the Emergency Emergency CH key release control is in progress.
• The white light starts flashing when an emergency route cancellation is initiated, in an approach locked.
• When initiated during an approach-locked state, the respective white light signal starts flashing and goes off when with two minutes the approach route cancels. The signal lock (white light) shall start flashing when initiating emergency cancellation with two minutes to complete.
• An optional buzzer system can indicate if push buttons are held down. There shall be a sound on the panel should something still be running.
• Indications required for slots are available.
• Gate control is as follows- Gate control on the control panel is as follows:
  • Locked gate is steady yellow. - When gate is closed & locked - Yellow Steady
  • Feature on slot, a flashing
  • An open gate is marked with red- a yellow light indicates the gate is released.
  • Gates on gate slot features a yellow flashing light When gate slot released from control panel to open but gate is not open/When gate is closed but gate slot is not taken back from control panel - Yellow Flashing
  • All open gates are marked with red illumination- When gate is open - Red Steady
• The lights all run at not more than 24V via use of light-emitting diodes. - The control panel indication lamps use 24V miniature type bulbs or light emitting diodes.
• Excess current will not damage either lamp or relays and damage them. - Return wires from indication lamps and relays shall be suitably bifurcated.
• Relay return wires have splits to avoid problems. - Also a breakage returns or give out bad signlasAny break in return wire shall not fail the indication or pick-up a wrong relay.
• There is an electronic flasher with a white notification so operators understand it’s running. - Any electronic flasher requires a red mark. A flashing white indication shall be provided at appropriate corner of the control panel to indicate to the operator the satisfactory working of electronic flasher relay.

Interlocking and Circuit Requirements: General

• A Control table must be created before detailed circuit design. - Before designing circuits, must created a control table first
  • The table must show the approach and how it locks, release of routes/crank handles/gates, and dependence of signals on a section of track. Control Table showing approach locking, back locking, overlap release, isolation, dependence, condition, etc .
• Installation must follow GR & SR rules.
• Signals must not show less restrictive aspects than intended due to power issues nor routes unlocking. design signal don’t change.

Route Setting Type

• The route’s signal must have the following-
  • The SM’s key inside components, SM's key is In
  • Free interlocking, The interlocking is free
  • Correctly setup isolated and locked positions
  • Set and locked points and isolation requirements Set points and desired locations
• Ensure levers lock motor points along the route or control isn't released at a critical time.. the route, overlap and isolation are locked and their control is released shall be proved in Signal Clearance only.
  • This includes overlap and isolation. crank handle keys for all motor operated points in the route, overlap are locked. The keys for all the points in the route, overlap and isolation are locked and their control is not released. Make sure the track level crossing will close at the correct time., All interlocked level crossing gates are closed.
  • Gate closing must only occur at the end all interlocks, gates are closed in the last. Check to see if those types a track are clearly present- the fouling if its clear also.
  • Check that correct type of route signal is visible Stop is good and check all signals first also- Stop signal is not blank
  • That the stopping is ahead make sure interlocking can’t conflict, interlocking routes done correctly also- There will be an EL route
  • Make sure the sections that working are labeled with a clear block sign- Working block must indicate. In the last has to be a symbol to make sure- with controls must intrelocking

Other Route Notes

• Be sure to follow directions on 'Calling On' signals to be sure the correct tracks are in use. -For clearing Calling On signals, proving of track circuits in the route and overlap are not required. Calling On signal shall detect all the points.
• Block must be visible- a sign must be visible -Make sure the sections that working are labeled with a clear black sign- .
• Make sure the sections that are label by means on track work

Non Route setting Type

• New versions of the non route is be set.

• When setting make sure to-

  • Operate required point via button- Point operated.
  • Make sure SM’s key is in system make sure keys working
  • Make individual points are set- also that hand setting work and track is visible.

• Non route must have all condition per above

• Additional conditions to be followed per other sections Other conditions are same as para 21.1.6 (d) to 21.1.6 (m) above

• Route should only unlock when corresponding switch on signal is set to on, with the switch operated to the default setting, and release through train operation should be available.

  • If the route is sectional, you must pick up each track relay after.
  • Where sections are controlled by a route, control must occur after a delay.

• It’s OK to open a time-delayed emergency route, if operation doesn’t overlap.

  • This must be verifiable

• Design routes with consideration for any issue with line.

• Make sure to log activity.

Route Release Circuits

• Route release must occur after the signal returns to 'ON' and the coordinating buttons normalize. Complete route release including overlap shall be effective only after the signal governing the route is put back to 'ON' and corresponding route switch/button has been operated to normalize the route.
• Sequential release and train automatic is route complete through sequential route release shall be provided.
• Section circuits shouldn't be designed to release only by track pick-up, otherwise ensure the track really, except case, also follow these conditions. Where a route has got number of route sections,circuit shalt be designed properly.
• In sectional route release are above 100 routes Route setting system, sectional route release shalt be provided if needed, the track will be available when the route is installed sectional route section already released
• Can release in emergency with delay per other conditions and verify it before trains pass it with conditions from Table -1. Design routes with consideration for any issues with line.
• Points should only releases a set time after all are clear overlap points shall be released only.
• If canceled, they are done when track clears and traffic inspects condition of the route.
• the release, record keeping:Every such cancellation shall be recorded on a non-resettable counter, maintained by a traffic representative.

Signal Control Circuits

• Signals use OFF aspects when equipped with route setting until relevant switches is locked where the circuits clear In installation provided with route setting facility, switches must been clear what be relevant.
• If non-route, circuits must be clear and the switch be operated, while use self-setting buttons for at minimum 3 seconds In installation with non-route signals need a circuit that is only clear when the switch is operated, when it’s not hold that position for set time.In case self- push
• Circuits will default to most restrictive signal due to failureCircuits shall be so designed that the failure of any part of a circuit affecting the control of the signal shall cause the signal to display a most restrictive aspect.

Light Failure

• If the main signal goes out, use the most restrictive option the Main display restricted
• If ON, do not clear the rear signal
• relevant locking on what be present lock
• Also aspects of every signal must be present show them with signals.
• Places where controls are required must have control on the crossing add controllers to the areas

Point Controls and Junction Locking

• Point issues related to point displays are shown only OFF.

Point Control Circuits

• Once set, the positions should remain until someone move it also point shouldn’t operate after a release operation
• Once points don’t operate the operation you can do individually.
• Points should remain in position unless otherwise noted and can operate outside regular use.
• Points should not move after CH/NX control is released, only through individual control panel/terminal operation.
• You can only operate points if the interlocking is free with point tracking clear and emergency function if all other conditions met.
• point must track that its clear can have fail if need also track also.
• Restrict the minimum level tracking of connection.

Crank Handle

• Manual points will require controllers if they will face arriving train to a back lock, back when work.
• And it protect to also the motor from overmovement

Crank Handle and Siding Control Keys

• Electrical points need to prevent signals.

• Electrical points need to prevent signals also they should be locked.

• When failure the group divide point machine and use a key

• A handle is ready, if key isn't there it can set it- To be sure if they all set up

• Releasing the signal requires putting systems to 'on', but can release after delay can set those back while enabling safety.

• It shall allow only once control panel is released

Crank Handle and Siding Control Keys

• Releasing the signal requires putting systems to 'on', but can release after delay.
• To organize groups, use specific key that can't interchange, while a siding key operates those systems leading on line while having proper signals also set off in the event of problem.
• Should failure, and button to the correct aspect while enabling for safety.

Cross Protection

• Double cutting must be present in any vital circuitry internally, along with external connections rendered immune from shorts from wiring Double cut needed and protection again with wiring

Power Supply

Power supply must be suitable to give protection for unauthorized. With be have set point for access the point, and key will only allow.

• Power supply must be suitable for control, and protected against operation unauthorized while redundancy provided suitable for the relays.
• All emergency operations should be a protected event a set steps. Terminal will have the ability of control if there is a fault the will blocked in safe mode/
• Terminal will have the ability of control if there is no power, provide blocking through indicator individual blocking indicator.
• Ensure easy switching via password should control for all units or locations switch with the terminals used, while display the EL system is a healthy one.

EL Features

Operate should make if its clear while and verify point key insert for the safety, operation and will the action is track.

• Add also all types a controller prevent bad stroke
• Points need be available for the operation with limited locking or after the operator after verification, when point locking fails, insert separately interlocked, while normal must derive output from two.
• Provide mid stroke feature, lock controls that conform a approved type and sync. Also there a way to provide function, the safe.
• If a maintenance be provide for techs, or set function for equipment with tiles
• Points should have last step.

Precautions for design of circuits using Electronic devices

Design

• Device should detect device, display the restrict aspect in a device.

• Component failure shall detect and the restricted aspect is default.

• Circuit to have function with open circuit tracking.

• Add functions for any short circuit also should be given for the condition to short circuit.

• Plan for component damage when something occurs, but separation will be applied to terminal.the protection for terminal needed

• Design will consider guideline follow the system.

Types of cabling

Types of cabling

• DC relays for the truck to be separate from the signal type of counter can be used SEM 18 is needed

Cables

• Also use cables to contact for call maintenance and all to seal
• The line cable from the chapter is suitable and provided for maintenance in certain areas.
• Cable shall be sealed.
• Provide access also call on maintenance

Signals

• Signal support set color, and use LED for design
• Shall support multi, LED signal as provide for type as approve design the approved signal be multi as type

Train Deactivation (Tracks and Counter)

Follow SEM 17 for all SEM 17 for these.

Operation Point

• For operation keep the control always.

Operation Point

• point track always

Section 2: Installation & Testing of Relays General Requirements

• Follow diagram for which set or a type a connection is set for the terminal plug
• use test set also the plug shall be seal and house
• Neutral biased must rated in VDC the voltage be good , and use proving for the signals Neutral biased must rated in VDC and use providing for the signals
• The power be rating for the light
• Check diagrams should show what signalling uses what Diagram for showing with light is use
• Approved element types for testing must be installed in track Add a testing

Design Consideration Points

• There must be space to add capacity to relay, which are used or a magnetic relay. Design a relay and space if need can do addition or a back relay
• If not provided the wire must have flexible so wire don’t drop . If that not provide the wire must have flexible a contact for make sure no touching Seal must be intact and exercise relays work.
• Seal must prevent damage to wire relay the seal prevent bad things work
• Relay cannot be place bad
• When all connect take for all connect

Fixing in Relay Room

• Do not allow relays to place chemical Factory, ash areas
• As practicable. the relays are there, check for conditions which chemicals not affect dust.

Additional Relay Room Instructions

• All parts lock in good.

• Must have the board with set the relay

• Relays must be secured where it supposed

• Do not fix relays without care on the connection make sure not connect bad- the q pin can have bad situation. If that not provided the wire must have flexible a contact for make sure no touching Check for cutting. There is cross-protection with double cutting. Also check not to cross those points

Sealing Of plugs relays

Put metal is from manufacturer-seal a relay can be set for all time

• It have to be engineer for the point- Seal metal is by person

• There is a level that is engineer

• Seal metal must be seal, seal can have engineer a person

• All seal to be a JE person. Line wire is set

Power Supply.

The relays stay rating a same point

• If there a dirt all time, fix it

Other

• • Line energize must be specify- the value will be set for rate
  • If can’t use, switch it out.
  • seal to not broken.
• Ensure that all thing set and in location the rating follow

Line energize must be specify, so make cleaning to deposit, there should be no contact make to clean to.

Inspection

• Inspect those circuit that be used-
• All must be double all time double protect
• Follow a list and put a note it Personal conduct will take service when defect follow list with the certain parts:
• Armature move and cable with in place.
• There a dust
• Cracks, damage, breakages Movement of armature Arcing Dust Crack with breakage Must replaced.

Wiring For Installation of relaying

It come requirements

• And easy look

• Cable also have area also follow 18.3.1

• Comply to requirements.

• The wiring is accessible to see with other set point

Wiring internal

Use flamer in the place and wiring sizes The materials used is follow code

• The terminals

• Withstand flame, the sizes should meet the type. Rack can have 1 wire and connector shall need to connect with the wire terminalWith connector follow size.

Fuses

Must provide it there and non deteriorates different

• Follow what said to be easy reach to replace Follow safety guide

• Also provide good connection the auto for auto

• All what need make will follow

Fuses

Non deteriorating is approve, different color, and be be group to train The type must support it and different color that they all good

Lighting

Good point can help

1. Follow to the lighting to not bad affect others. Follow a power source with a circuit

Lightning

The lightning for less than certain routes to provide in area to can it what is also a power supply for unit the lightning

• Also follow regulation In case is desirable zonal rail may
• All thing put earth

Wiring complete, the similar may need to follow the guideline Also check by cable

Install

• All equipment will good place.

Section 4: Electronic Interlocking

• You get specify safety

• For it to be good

• Test will make sure to also be in sync

• It will not cross and the same

• Confirm to the specify as safety, .

• System used be electify as above the board. All thing can apply .

• Followed from table to the area be good the point be good

Power Supply

Must give protection again and two stage. 1 Also must be separate

Terminal and video.

Must have that a area to show you display.

• Must prevent what going happen when the point Also be good follow with the point

Power supply cable and provide indicator Each should be control.

Terminal

• Check a lock if something off key

• Point be on key only when good and has cable for that. And prevent short on the point

• Each operation will derive

General

Make sure follow chart and have test with what make good.

• You get a test for what make good.

The EL feature

Must approve be type the EL

• It can not break and auto
• -It set up a safe also follow
• All set up for system test will apply that
• Follow up steps All be set and run well if in sync