
Explore the trip command and logic across local, remote, emergency, and off controls, including two trip coils and anti-slam and drift-free schemes in medium voltage switchgear.
Explore the trip circuit logic table, detailing test and service positions and the middle position, and how local and remote commands govern breaker tripping during testing and emergencies.
Learn how the trip coil safe feature in a medium voltage circuit breaker cuts off the DC trip supply as soon as the breaker opens, preventing prolonged coil energization.
Explore how the CB trip control operates the tripping circuit using the tripping coil, DC supply, and selector switches (local, remote, emergency) to energize the trip and open the breaker.
Understand how the test switch circuit uses two tripping contacts in series to protect relay contacts, with test plugs and banana connections enabling timing measurements via a timer relay.
Explain the tripping command from protection relays, energizing the tripping coil to trip the breaker, and note the absence of local remote contacts ensuring the system can always trip.
Explore how local and remote trip commands operate in medium voltage schematics, using the S1 position, F1 interlock, and binary inputs to a cpu-based protection unit.
Explore how busbar protection in medium voltage switchgear issues a trip command to all feeders, using tripping coils in a single bus, single breaker configuration.
Explore the trip coil two circuit in medium voltage schematics, including dual dc supplies and two tripping coils, with under voltage and under frequency tripping and trip circuit supervision relay.
Understand trip circuit supervision relays (TCS) that monitor the DC supply and tripping coils, detecting failures, loose or open wire, or coil is bound or open, to ensure breakers open.
Dear All,
Welcome to the course "Mastering Medium Voltage Schematics". This training starts from a very basic level to an advanced level. Focus has been given to delivering practical and hands-on knowledge.
Trainer Introduction:
Your trainer brings over 21 years of experience in operation & maintenance, erection, testing, project management, consultancy, supervision, substation automation, SCADA, and commissioning. With a background spanning power plants, high voltage substations, and HVDC installations, he has worked with renowned organizations such as Siemens Saudi Arabia. He has been involved in over 20 high-voltage substation projects across Pakistan and Saudi Arabia.
His expertise encompasses a wide range of areas including protection systems, substation automation systems, design, testing, and commissioning of power generation systems, high voltage switchgear, protection relays, and control schemes. He has a proven track record of leading testing and commissioning teams for implementing electrical infrastructure projects for industrial clients, including steel and petrochemical industries.
This online course is part 03 of the Mastering Medium Voltage Switchgear drawings. In this part we have covered the following topics.
•Trip Command and logic table
•Trip coil save scheme
•Anti slam scheme
•Trip free scheme
•CB Trip control Local / Remote / Emergency / OFF
• Tripping from Local / Remote
•Tripping from Emergency
•Trip coil 1 & 2 circuit
•Tripping from OC relay
•Tripping from BB relay
•Tripping from UV / UF Relay
•Trip circuit supervision relay
•Sold DC, Ghost DC, Return DC
•Test Lamp
•ABB TCS Relay
•MVAX 11, 12 ,13 TCS Relays
••Indication circuit
•Binary input circuit
•Loop supervision
•DC supply supervision
•Interlocking of OG feeder with Earth switch
•Trip Circuit Supervision Alarm and Close block logics
•Each TCS create alarm
•Both TCS fail means CB can’t be open if closed, that is dangerous
•Concept of CB close block if both TCS fails
•When to monitor healthiness of TC , CB is closed or open
Concept of Ghost / Fake DC, Solid DC & return negative and positive supplies.
•What is it mean by Solid DC
•What is return negative or positive
•Ghost / Fake DC
•Use of Test Lamp
•Test lamp supersede any high-tech tools for trouble shooting
Trip circuit supervision relay SPER 1C1
•Continuous monitoring of circuit-breaker trip circuits and other essential control circuits
•Preset operate time preventing unwanted alarm signals at circuit-breaker operation
•Indication of relay operation with LED indicator on the front panel and output relay
•Detects bad contact, contact welding and auxiliary voltage failures in the supervised circuit
TCS Supervision Relay MVAX12
Best Regards