BARC Seismic Switch (Digital) is packed with many distinctive features specially designed for meeting the standards for nuclear industries. This can be helpful in highly accurate detection of a strong earthquake or a structural vibration with various safe shut down options. This has a broad range of applications such as Industrial Processes, Chemical Processes, Gas Valves, Hazardous Systems, Solenoids, elevators, walkways, Electronic gates and doors.
Seismic Switch (Digital) monitors its attachment point to detect seismic (earthquake) motions in all 3 mutually perpendicular axes(X, Y and Z). It monitors acceleration in all the three axes and triggers on detection of Peak Ground Acceleration (PGA) on any axis. The unit provides two numbers of 2 Form C (DPDT) isolated relay contacts. Relay 1 (Earth quake relay) and Relay 2 (Status relay). Coils of both these relays are in energised state during normal operation and de-energises on any fault. This ensures ‘fail safe’ operation of the system. On-line testability is another important feature in this system which enables the user to manually initiate the self-diagnostics of the system without removing it from the installation. Seismic Switch (Digital) can communicate to a Graphical User Interface Software through an RS-485/RS-232 link. Various features of this software include remote reset for automatic leveling, self test, password protected access, saving instrument details in EEPROM, setting trip parameters, display of battery status, real-time plots of accelerations and display of various other system parameters such as voltage and temperature. The system can be programmed for having additional triggering conditions such as Cumulative Average Velocity (CAV).
| Default trigger condition | Peak Ground Acceleration (PGA) on any Axis. settable range: 0.005g to 1.7g |
|---|---|
| Features | Fail safe design, Online testability, manual and automatic self test |
| 3 dB Cut-off frequency on each axis | 13.5 Hz |
| Output | Two numbers of Potential free 2 form C (DPDT) relays with contact rating of 1.0A at 24VDC - Earth quake relay and status relay |
| Battery | Lithium-ion battery. 3700mAH X2(10Hrs Backup) Automatic charging during main power operation |
| Calibration | Generally not required. Tilt table can be used for verifying the calibration |
| Enclosure and mounting | Rugged IP 66, 4 M8 mounting holes for easy installation |
| Operating Temperature | 0-70 Degree Celsius |
| EMI/EMC | Designed to meet IEC-61000-4.2, 4.3, 4.4 ,4.5,4.6 and 4.8 (to be tested) |
| Chip software | MISRA-C 2006 Complaint. (Verification Under Progress) |
| MTTF | >80 Years (As per MIL-HDBK-217PLUS) |
| Software features | Remote reset for automatic leveling, self test, password protected access, saving instrument details in EEPROM, setting trip parameters, display of battery status, real-time plots of accelerations and display of various other system parameters such as voltage and temperature |
BARC Seismic Switch (Digital) is packed with many distinctive features specially designed for meeting the standards for nuclear industries. This can be helpful in highly accurate detection of a strong earthquake or a structural vibration with various safe shut down options. This has a broad range of applications such as Industrial Processes, Chemical Processes, Gas Valves, Hazardous Systems, Solenoids, elevators, walkways, Electronic gates and doors.
Seismic Switch (Digital) monitors its attachment point to detect seismic (earthquake) motions in all 3 mutually perpendicular axes(X, Y and Z). It monitors acceleration in all the three axes and triggers on detection of Peak Ground Acceleration (PGA) on any axis. The unit provides two numbers of 2 Form C (DPDT) isolated relay contacts. Relay 1 (Earth quake relay) and Relay 2 (Status relay). Coils of both these relays are in energised state during normal operation and de-energises on any fault. This ensures ‘fail safe’ operation of the system. On-line testability is another important feature in this system which enables the user to manually initiate the self-diagnostics of the system without removing it from the installation. Seismic Switch (Digital) can communicate to a Graphical User Interface Software through an RS-485/RS-232 link. Various features of this software include remote reset for automatic leveling, self test, password protected access, saving instrument details in EEPROM, setting trip parameters, display of battery status, real-time plots of accelerations and display of various other system parameters such as voltage and temperature. The system can be programmed for having additional triggering conditions such as Cumulative Average Velocity (CAV).
Table 1 : Specifications of Digital Seismic Switch.
| Sr. No. | Specification | Value |
|---|---|---|
| 1 | Actuation Methods | Peak Ground Acceleration (PGA) on any Axis. Default 0.1g on each axis 0.005g to 1.7g with a set point accuracy of 0.005g. The set point can be fixed through RS-232 /RS-485interface. Standardized Cumulative Average Velocity (CAV) Default CAV Threshold (0.025g ) and Trip on 0.16 g-sec |
| 2 | 3 dB Cut-off frequency on each axis | 13.5 Hz |
| 3 | Output | Two numbers of Potential free form C relays with contact rating of 1.0A at 24VDC. Earth quake relay and status relay. Relay actuation conditions is given in the table 1. |
| 4 | Closure Timing | On seismic event, relay will remain actuated for user settable time period. Typically set for 5 Seconds. |
| 5 | Battery | Lithium-ion battery. 3700mAH X2 (10Hrs Backup) |
| 6 | Battery Charging | Battery will be charging while system is operated on mains power. Automatic switching to battery during power outage |
| 7 | Enclosure | IP 66 |
| 8 | Operating Temperature | 0-70 Degree Celsius |
| 9 | Calibration | Generally not required. Tilt table can be used for verifying the calibration |
| 10 | EMI/EMC | As Per IEC-61000-4.2, 4.3, 4.4 ,4.5,4.6 and 4.8 (to be tested) |
| 11 | Functional verification on Shake Table | Yes |
| 12 | Warning conditions | Over temperature; Power supply errors, Flash memory checks and Battery Charging error through status relay. RS-232 /RS-485 communication can be used for detailed diagnosis |
| 13 | Chip software | MISRA-C 2006 Complaint. (Verification Under Progress) |
| 14 | GUI Software | Settings to EEPROM Real time Plot and Data Storage Self test command Password protected access |
| 15 | MTTF | >80 Years (As per MIL-HDBK-217PLUS) |
Table 2 : Various Triggering conditions of Digital Seismic Switch.
| Condition | Earthquake Relay | Status Relay |
|---|---|---|
| Earth quake | Actuates for 5 seconds | No Actuation |
| Complete power loss including battery | Actuates and latches till power restores | Actuates |
| Manual confidence test | Actuates for 5 seconds | Actuates for 5 seconds |
| Working on battery | No actuation. It will actuate on detection of earth quake | Actuates when battery power is less than 98% |
| Automatic confidence test pass | No actuation | Actuates for one second |
| Automatic confidence test fail | Actuates | Actuates |
| Warning condition | No actuation | Repeated actuation in 2 seconds interval |
BARC Seismic Switch (Digital) is packed with many distinctive features specially designed for meeting the standards for nuclear industries. It can be helpful in highly accurate detection of a strong earthquake or a structural vibration with various safe shut down options. This has a broad range of applications such as Industrial Processes, Chemical Processes, Gas Valves, Hazardous Systems, Solenoids, elevators, walkways, Electronic gates and doors.
After Fukushima incident it has become a regulatory requirement to have Automatic Reactor Trip System (ASTS) on detection of earthquake. This is designed to scram the reactor upon the occurrence of a seismic event, before turbine trip or other conditions resulting from the seismic disturbance could cause a scram. The earlier scram could give a lead time between 5 to 20 seconds. The lead time could provide resulting benefits such as reduced loads during the seismic event and, therefore, fewer burdens on the plant systems. It may also reduce the likelihood of a LOCA or severe transient after a seismic event. ASTS comes under classification as safety Class IA system (reactor protection) and has to meet the relevant standard requirements such as on-line testability, fail safe and other qualification requirements. Since systems that are available in the market and not meeting these requirements, BARC has developed fully functional prototype designs of the Seismic Switch.
FACILITIES REQUIRED / INFRASTRUCTURE REQUIREMENT FOR COMMERCIAL PRODUCTION
