Industrial Control - NEMA/EEMAC Terminal Blocks
Terminal block, tubular screw without pressure plate. Terminal block, screw terminal with #6 screw. Certifications, Click to enlarge - 1492-16-3a ...
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Reliable clamping of the conductor is ensured by the force-increasing swiveling movement of the angled PRESSURE PLATE, which is supported in the rugged clamping part pocket such that it can swing freely and presses the conductor against the power rail.
Method of operation of a screw connection with pressure clip technology
http://www.phoenixcontact.ca/pcb-terminal-block/226_51580.ht...

Terminal blocks with a rising cage clamp keep constant force on the screw, preventing loosening or backing out. This screw-locking technique greatly eliminates or reduces potential problems in applications with high vibration or extreme temperature variations.

The technique is simple: As the screw is tightened, the PRESSURE PLATE moves upward toward the conductor to be clamped, while the conductor stays stationary. Once the pressure plate contacts the conductor, it exerts increasing pressure, resulting in an equivalent upward counter force on the threaded bar.
http://www.connectorsupplier.com/Problem_Solved_Phoenix_9-15...

I prefer switches and receptacles with PRESSURE-PLATE CONNECTIONS and I will buy those for new installations or replacements. But for old wiring when there are only screw terminal connections, what do you recommend?
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I would use PRESSURE PLATE DEVICES. Although fork terminals are good there's a lot of wasted labor in installing them on every conductor.
http://forums.mikeholt.com/archive/index.php/t-126494.html

The following clamping methods are used: Terminal body with PRESSURE PLATE for terminal sizes 16, 35 and 70. Strain-relief clamps for terminal sizes 2.5, 4 and 6. Screw with connection disk for fuse terminals and component terminals.
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Damage to the clamped conductors is prevented by PRESSURE PLATES or strain-relief clamps. For the connecting cross-sections when 1 or 2 conductors are connected, see "Technical specifications
https://eb.automation.siemens.com/goos/Catalog/Pages/Product...

Angled PRESSURE PLATE for reliable clamping of all conductor types, ... Screw connection; 300V / 65A UL; 24 - 6 AWG; 10 mm pitch ...
www.phoenixcontact.com/pcb-terminal-block/32102_29901.htm plates or strain-relief clamps
www.reco.net/pdfs/ALPHA-FIX-Terminal-Blocks.pdf