Test block & plug systems

Test links are an important accessory for protection, metering and control panels. They enable test technicians to quickly and safely isolate protection relays so that test signals may be injected and system performance verified.

  • 4M200 Test Block system

    Read more The 4M200 Test Block system is an evolution of the 14 test circuit versions widely employed in the power utility sector. The primary difference is the incorporation of ‘finger safe’ test sockets which allow the use of shrouded 4mm banana plugs. A number of 4M200 Test Block configurations are available to suit specific protection and control applications as depicted in the wiring diagram examples. The 4M200 Test Block has 14…
  • 4M300 Test Block System

    Read more The Test Block type 4M300 comprises fourteen (14) test circuits, each of which is connected to a separate pair of terminals at the rear of the case. During the normal operation of the associated protection equipment, each pair of terminals are connected together by a circuitshorting link. Changing the 4M300 Test Block from the normal service condition to the test condition is described below & depicted in figure 3 in…
  • 4M400 Flexible and high performance test block system

    Read more The 4M400 Test Block is an evolution of our popular 4M300 system. The main difference is that each of the fourteen (14) test groups may be specified at time of order to provide automatic CT shorting and sequential circuit to suit specific protection schemes: Stage 1 isolation CT shorting Stage 2 isolation The main advantage of this approach is the improved level of safety and security afforded to the CT…
  • 4M402 Flexible and high performance test block system

    Read more The 4M402 Test Block is an evolution of our popular 4M300 system. The main difference is that each of the twenty eight (28) test groups may be specified at time of order to provide automatic CT shorting and sequential circuit isolation to suit specific protection schemes: STAGE I Test Block Cover Extraction Isolation of Type 1 circuits STAGE II Isolation Plug Extraction CT Shorting Automatic shorting of all CT circuits…