Terminal blocks
One of the simplest components of an electrical circuit are the terminal blocks. They’ve just got two simple functions: firstly, linking up the terminal blocks’ wires to make them conductive, and secondly, holding the wire ends in place. To fulfil these functions properly in the long time, though, an array of physical aspects need to be taken into consideration. Many of these are misunderstood. All terminal blocks have the same essential components. The wire ends to be connected are pushed onto the connecting bridge but remain detachable.
An overview of terminal blocks
Screw terminals
Screw terminals are the bulkiest terminal blocks for the best contact.
- Maximum power transmission
- Screw terminal with side contact
- A screw for all applications
- Inscription panel, front
- The best-selling terminal in Switzerland
Spring-loaded terminals
Spring-loaded terminals are quick to assemble and provide medium-strength contact.
- Functional operation of all elements
- Inscription panel, front and side
- Compatible with cross-connection rakes
Spring-cage terminals
Spring-cage terminals are the most affordable terminal blocks but provide the weakest contact.
- Push-in terminal with comfortable contact
- Large cross-section area measuring 0.5–4 mm²
- Inscription panel, front
- new, pluggable cross-connection rakes
The right technology for every application
Technical background
Comparison with maximum power transmission
Clamping force depends on:
- Torque
- Spring force (limited by housing’s resilience, wire/strand bending strength)
Contact resistance
Contact resistance and contact quality depend on:
- Contact surface
- Contact force
- Contact material
- Impurity layers (oxides, dirt)
Assembly times – difference
The truth about assembly times and the difference between screw terminals and spring-cage terminals.
Moving forces when shaken
Moving forces depend on:
- Mass of the conductor
- Frequency of movement
- Clamping force > as moving force
Heat dissipation
Generation of heat depends on:
- Contact quality
- Current
- Surface area of metal parts
- Heating capacity (bufferable heat quantity) of metal parts
Heat dissipation
Generation of heat depends on:
- Contact quality
- Current
- Surface area of metal parts
- Heating capacity (bufferable heat quantity) of metal parts
Electrical components
Profile rail, item no. 4382 and 4383, type C30
29×15×2mm and 32×18×3mm
- available in four different materials
- We can provide all lengths of profile rails with a price supplement for the cut
- Profile rails are also available with fastening holes or straps for an additional cost
Combo rail, item no. 80291, DIN35/C30
29×15×2mm and 32×18×3mm
- outside flanks in line with EN 60715
- to snap blocks and devices in line with DIN35
- Interior profile to include slot nuts, series no. 4420 and no. 44320, and fixing brackets, series no. 4350
Fixing bracket with aluminium alloy
for profile rails, no. 4382, 4383 and 80291, type C30
- also available in A4 stainless steel
- with six-sided slotted screw
- Wire base plates are always required to lay wires