ABB RAM Memory Module PCM 21 H&B Contronic

ABB RAM Memory Module PCM 21 H&B Contronic

Basic Information

Dimensions and weight: Its estimated shipping dimensions are approximately 2.5 x 13.2 x 25.4 cm and its weight is approximately 0.2 kg.

Origin and Warranty: The module is of Swedish origin and is normally supplied with a 12-month warranty.

Performance features

Memory type and function: As a RAM memory module, the PCM 21 provides temporary data storage and fast data read/write functions for the system. In industrial automation control systems, it can be used to store dynamic data during system operation, such as sensor data collected in real time, intermediate calculation results, etc., so that the CPU can quickly access and process these data, thus realising real-time monitoring and precise control of the production process.

Data read/write speed: Although the specific read/write speed is not explicitly given, generally speaking, this kind of industrial-grade RAM memory module can meet the real-time requirements of the control system for data read/write to ensure that the system can quickly and accurately obtain the required data during operation, thus supporting the efficient operation of the system.

Compatibility: PCM 21 has good compatibility with other components of the H&B Contronic series, and can work seamlessly with CPU modules, input/output modules and other devices of the series to build a complete industrial automation control system, ensuring that all parts of the system can work together to achieve precise control and monitoring of the production process.

Reliability and Stability: Adopting high quality electronic components and advanced manufacturing process, it has high reliability and stability. It can operate stably for a long time in harsh industrial environments, resisting the influence of electromagnetic interference, temperature changes, humidity changes and other unfavourable factors, thus ensuring the normal operation of the system and reducing the downtime of the system caused by hardware failure.

The transfer sequence of OTM_C21D can be summarized in following steps: 

• An anomaly occurs on the Line 1 (LN1) 

• Generator start, immediately start generator in case of black-out, phase-loss, overvoltage or undervoltage (If Generator mode is selected) 

• The Line 2 start the normal functioning,  transfer delay Ts 

• Change-over switch (Switch I) to the position 0 

• Change-over switch (Switch II) to the  position II

FEATURE

• Low-impedance busbar protection 

• Stub and T-zone protection 

• High functional reliability due to two independent measurement criteria: 

- stabilized differential current algorithm 

- directional current comparison algorithm 

• Phase-by-phase measurement 

• Reduced CT performance requirements 

• High through-fault stability even in case of  CT saturation 

• Full solid-state busbar replica 

• No switching of CT circuits 

• Only one hardware version for  

- 1 and 5 A rated currents 

- all auxiliary supply voltages between  48 V DC and 250 V DC 

- nominal frequencies of 50, 60 and  16.7 Hz 

• Short tripping times independent of the  plant’s size or configuration 

• Centralized layout: Installation of hardware  in one or several cubicles 

• Distributed layout: Bay units distributed  and, in the case of location close to the  feeders, with short connections to CTs, isolators, circuit breakers, etc. 

• Connections between bay units and central  unit by fiber-optic cables 

- maximum permissible length 1200 m  

- for distributed and centralized layout 

• fiber-optic connections mean interference proof data transfer even close to HV power  cables 

• Replacement of existing busbar protection  schemes can be accomplished without restrictions (centralized layout) in the case of  substation extensions e.g. by a mixture of  centralized and distributed layout 

• Easily extensible