Relays for Railway Signalling Overview
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Questions and Answers

What are the two main classifications of relays mentioned in the content?

Shelf type and Plug-In Type.

Which style of relay is specified for use in internal circuits except in AC RE areas?

QN1 Style Relay.

What is the working voltage of the QS3 Style Relay?

12 V DC.

How does the QB3 Relay ensure continued operation under high voltage conditions?

<p>It has biasing that stands good up to 240 Volt DC.</p> Signup and view all the answers

Describe the configuration of the QNN1 Style Relay.

<p>It comprises two neutral line relays with a common heel piece, and they operate independently.</p> Signup and view all the answers

What is unique about the AC Immunised DC neutral line Relay’s design?

<p>It achieves immunisation intrinsically without external means.</p> Signup and view all the answers

What happens to the front contacts of the AC Immunised Relay when 1000 V AC is applied?

<p>It does not make any of its front contacts.</p> Signup and view all the answers

What specification do all the mentioned relays conform to?

<p>B.R.S. Specification No.930A.</p> Signup and view all the answers

What type of relay is QT2 and what is its primary usage?

<p>QT2 is a type of relay used as a track relay in Non-RE areas.</p> Signup and view all the answers

Describe the significance of the copper slug in QTA2 relays.

<p>The copper slug in QTA2 relays provides AC immunity.</p> Signup and view all the answers

What are the pickup voltage and current for QBAT relays?

<p>The pickup voltage for QBAT relays is 1.75 V and the pickup current is approximately 175 mA.</p> Signup and view all the answers

How does the contact configuration differ between QT2 and QTA2 relays?

<p>QT2 has 2F-1B contacts, whereas QTA2 features a 2F-1B contact configuration as well.</p> Signup and view all the answers

What is the primary role of timer relays in signaling circuits?

<p>Timer relays are used to release interlocking after a specified period for safety.</p> Signup and view all the answers

What are the limitations regarding the track circuit lengths for QTA2 relays in RE areas?

<p>QTA2 relays can be used up to 450 meters with a choke at both ends and have specific limits without chokes.</p> Signup and view all the answers

What distinguishes QT2 relay construction compared to the shelf type relay?

<p>QT2 has a single coil and fewer contacts compared to the two-coil construction of shelf type relays.</p> Signup and view all the answers

In terms of operating power, how do QTA2 relays compare to QT2 relays?

<p>QTA2 relays require more D.C. operating power and have slower pickup and dropout times compared to QT2 relays.</p> Signup and view all the answers

What is the main function of the QNA1 relay?

<p>The QNA1 relay serves as an external relay in electronic interlocking systems.</p> Signup and view all the answers

How does the QBA1 relay achieve its immunity?

<p>The QBA1 relay achieves immunity through the provision of a copper slug and a permanent magnet for biasing.</p> Signup and view all the answers

What distinguishes the QBCA1 relay from the QBA1 relay?

<p>The QBCA1 relay has two heavy-duty front contacts and can carry higher inductive currents than the QBA1 relay.</p> Signup and view all the answers

Why is the QSPA1 relay specifically used as a repeater for certain track relays?

<p>The QSPA1 relay is used as a repeater due to its slow to pickup characteristic, making it suitable for Q series track relays.</p> Signup and view all the answers

What type of relay is the QL1 relay and how does it maintain its state?

<p>The QL1 relay is a magnetically latched DC line relay that remains in an operated condition even when the power is cut off.</p> Signup and view all the answers

What type of contact is required for track relays in non-electrified areas?

<p>Track relays in non-electrified areas must be of the metal to carbon contact type and normally be of plug-in type.</p> Signup and view all the answers

What specifications must track relays comply with in electrified areas?

<p>Track relays in electrified areas must be 9 ohm DC neutral, AC immunized, or 9 ohm DC biased, AC immunized.</p> Signup and view all the answers

What is the immunisation method used in QLB1, QBA1, and QSPA1 relays?

<p>The immunisation method for these relays involves incorporating a copper slug on the core.</p> Signup and view all the answers

What is a significant feature of the Minor Group relays in Siemens interlocking?

<p>They can replace multiple neutral relays with interlocked relays or contactor relays.</p> Signup and view all the answers

List the configurations available for Non AC immunised Neutral Relays.

<p>They are available in 4F/4B, 5F/3B, and 6F/2B contact configurations.</p> Signup and view all the answers

What is the ohmic value of interlocked relays across all contact configurations?

<p>The ohmic value is 615 ohms for all configurations.</p> Signup and view all the answers

How does the configuration of AC immunised relays differ from Non AC immunised relays?

<p>AC immunised relays are available only in 5F/3B configuration, while Non AC immunised can vary.</p> Signup and view all the answers

What is the function of the Universal ECR relay in the context provided?

<p>It serves as a lamp proving relay.</p> Signup and view all the answers

Identify the contact configuration available for double coil relays mentioned in the content.

<p>They are available in 5F/3B contact configuration.</p> Signup and view all the answers

What differentiates the WKR1 and WKR2 relays based on their specified configurations?

<p>Both are available in 5F/3B contact configurations, but WKR1 has a specific role in point detection.</p> Signup and view all the answers

What is the importance of the ohmic values provided for the relays?

<p>They determine the current flow and compatibility in various applications.</p> Signup and view all the answers

What is the ohmic value of the relays used for point detection?

<p>1840 ohms</p> Signup and view all the answers

What is the function of the WJR relay?

<p>To provide a 10-second time duration for point operation.</p> Signup and view all the answers

What contact configurations are available for the WR (Heavy Duty contactor Relay)?

<p>2F/2B contact configurations.</p> Signup and view all the answers

What is the voltage requirement for the Siemens Motorised Clockwork Timer?

<p>11 OV A.C. +/- 10%.</p> Signup and view all the answers

What type of relays are approved for ECR applications?

<p>Relays of an approved type.</p> Signup and view all the answers

What is the ECR pickup current at 50Hz?

<p>108 mA/AC.</p> Signup and view all the answers

What is the consequence of an interrupted energising circuit in a Siemens Timer?

<p>The mechanism returns to its normal position before actuating the contacts.</p> Signup and view all the answers

What is the maximum continuous current the ECR can withstand?

<p>250 mA/AC.</p> Signup and view all the answers

What are the two primary components of the DC Thermal Type Element Relay (QJ1)?

<p>The two primary components are a heating element (H) and a neutral line relay (R).</p> Signup and view all the answers

What are the maximum operations recommended per day for the DC Thermal Type Element Relay, and why?

<p>The maximum operations recommended are 100 per day to avoid changing the characteristics of the heating element.</p> Signup and view all the answers

Describe how the Electronic Timer Relays achieve time delays.

<p>Electronic Timer Relays achieve time delays through charge and discharge methods or by counting clock pulses.</p> Signup and view all the answers

List the group classifications for K-50 relays and provide an example of what is included in a Mini Group.

<p>K-50 relays are classified into Mini Group, Minor Group, and Major Group. A Mini Group includes 2 neutral control relays and 2 interlocked relays.</p> Signup and view all the answers

What happens to the timing in a DC Thermal Type Element Relay if there is a 10% increase in applied voltage?

<p>A 10% increase in applied voltage may result in a time decrease of up to 10%.</p> Signup and view all the answers

Study Notes

Relays for Railway Signalling

  • Relays are electromagnetic devices used to close or open electrical circuits.
  • They can be shelf type or plug-in type.
  • They operate on an electromagnetic principle, using a base electromagnet, armature, contacts, springs, and a cover.
  • Relays operate on low current.

Metal to Carbon Line Relay - Non- AC Immunized Relays

  • QN1 Style Relay: Used in internal control and detection circuits (except AC areas).

  • Immune to 300V AC 50Hz (except in emergencies in AC areas).

  • Specification BRS No: 930A

  • QS3 Style Relay: Sensitive line relay, operating on 12VDC.

  • Specification BRS No: 930A

  • QB3 Relay: Biased neutral line relay, operating on 12VDC.

  • Contact configuration 4F/2B. Biasing up to 240VDC.

  • Specification BRS No: 930A

  • QNN1 Style Relay: Comprises two neutral line relays.

  • Contacts and magnets are mounted side-by-side.

  • They operate independently.

  • Specification is BR specification 960.

Metal- Carbon - AC Immunised Q- style line relays

  • AC Immunised DC neutral line Relay: Immunisation is intrinsic, without external components.

  • Does not make any front contacts with 1000V (rms) 50Hz AC applied to terminals.

  • Does not break any back contacts with 300V (rms) 50Hz AC applied to terminals.

  • Confirmation with IRS Specification No. S60 -78.

  • Usage in Electronic Interlocking systems.

  • QNA1 Relay: Immunisation achieved through a copper slug on the coil core.

  • Otherwise similar to QN1.

  • Specification BR specification no. 931A

  • External relay usage.

  • QBA1 Relay: DC biased AC immune neutral line relay.

  • Copper slug for immunisation, permanent magnet for biasing.

  • Does not operate if 20 times rated voltage is applied in reverse direction.

  • Specification BR Specification No. 932A

Track Relays

  • Track relays are typically metal to carbon contact type, usually plug-in type, unless otherwise specified in non-electrified or electrified areas
  • Resistances vary depending on the area and type of relay.
  • Relays such as QT2, QTA2 and QBAT are commonly used in track circuit applications.

Timer Relays

  • Used in signalling circuits for releasing interlocking after set time periods for safety.
  • Types include DC Thermal (QJ1), Siemens motorized clockwork, motor type, and electronic types.

Metal to Metal Relays

  • K-50 relays: Available in mini, minor, and major groups; varying capacities based on size.
  • Used in various point control applications (interlocking, etc.)

ECR Relays

  • Relays of approved type.
  • Plug-in type relays (Neutral/Polar Biased/Magnetic latch/Interlocked) rated at 24, 48 or 60 VDC are normally used.
  • Suitable LED lamp proving relays are used to suit various LED lamps.

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Railways Signaling Relays PDF

Description

Explore the essential functions and types of relays used in railway signalling systems. This quiz covers electromagnetic principles, various relay styles, and their specifications, focusing on both AC and DC applications. Test your understanding of how these components ensure the safe operation of railway circuits.

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