Basics of terminal blocks and their various subtypes
- Terminal blocks for the transmission of I/O signals
- Terminal blocks for power distribution
- Terminal blocks for motor connections — including single-phase and three-phase motors for various industrial uses
- Terminal blocks to serve as ground blocks — designed specifically to make connection to ground)
How do you wire a terminal block?
Dec 28, 2018 · A terminal block is a tool used to safely connect two or more wires together. Also known as a terminal block connector, these blocks use a clamping component and conducting strip to secure and organize connecting wires. A terminal block allows users to join multiple outgoing wires to one singular incoming wire, thanks to its insulated frame and multiple …
What is a terminal block used for?
Apr 06, 2020 · A terminal block is used to fasten or terminate wires. It is often used to connect wiring to a ground or electrical switches and outlets to the mains supply. A simple design has several single terminals positioned in a long strip, with an insulating frame and a clamping part. There are several types and structures for terminal blocks.
What is the function of terminal blocks?
Jun 01, 2020 · What is the purpose of a terminal block? Terminal blocks are used to secure and/or terminate wires and, in their simplest form, consist of several individual terminals arranged in a long strip . Terminals are useful for connecting wiring to a ground or, in the case of electrical power, for connecting electrical switches and outlets to the mains.
How to select a terminal block?
Terminal blocks are modular, insulated blocks that secure two or more wires together. Terminal blocks are used to secure and/or terminate wires and, in their simplest form, consist of several individual terminals arranged in a long strip. Terminals are useful for connecting wiring to a ground or, in the case of electrical power, for connecting electrical switches and outlets to the …
What is the purpose of a terminal tool?
What is the use of test terminal block?
Can you use terminal blocks in residential wiring?
What is TTB in electrical?
What is a test block for electrical?
How many wires can you put in a terminal block?
Are terminal blocks safe?
Is it OK to use a junction box?
Why use terminal blocks?
Using terminal blocks is a much better solution for connecting wires. Terminal blocks provide more flexibility. For example, when using terminal blocks, wiring modifications are easy because wires can be removed or added quickly.
What is the purpose of a ground terminal block?
Instead of connecting wires, the Ground terminal block connects the incoming wire to Ground.
What is a barrier terminal block?
The Barrier terminal block is very similar to a Screw-in terminal block as they use screws to clamp the wires. Depending on the application and environment, the Barrier terminal strip may have a small lid to protect the wiring.
How are terminal blocks mounted?
Terminal blocks are mounted in a variety of ways but by far the most common is by attachment to a DIN Rail. A DIN Rail is a metal rail of a standard size universally used for mounting devices and components inside electrical panels and equipment racks.
What is a thermocouple block?
A Thermocouple block is designed to accept thermocouple lead connections. Thermocouples cannot be connected to typical terminal blocks.
What is the difference between a spring loaded and a push fit terminal block?
The big difference between the Spring-loaded and the Push-fit terminal block is the method of wire release. Push-fit terminal blocks have the release device mounted right next to the wire insertion point.
What are terminal blocks classified?
Terminal blocks are classified based on characteristics such as structure, device type, and termination options. Let’s explore some of the classifications and characteristics of terminal blocks typically encountered in industry today. There are a variety of methods used to connect the wires inside the terminal block.
What is a terminal block?
Most terminal blocks are usually modular and mounted on DIN rail. That allows us to increase the number of terminals according to the requirements. Terminal blocks keep connections much more secure and wires well organized.
What is dual level terminal block?
Dual level terminal blocks: These blocks have another level of connection terminal stacked on the first one. This arrangement is generally used to save space.
What is a single level pass through terminal block?
Single level pass-through terminal blocks: These are simply used to connect two wires together, i.e. wire-to-wire connection. These are also called as single feed terminal blocks. Single level terminal blocks are of the most simple type having one input contact and one output contact.
What is a power distribution block?
An electric power distribution terminal block is a convenient, economical and safer way to distribute power from a single input source to multiple outputs. One large wire is connected to the input terminal of the block and multiple output terminals are provided at the output. This way, wires are well arranged in a control panel giving it a neat, clean and professional look.
What is push in terminal?
Most push-in terminals require the use of a ferrule. A ferrule strengthens the end of the wire/conductor. However, some push-in terminal blocks allow to insert a solid conductor directly or a stranded conductor by inserting a screwdriver into the release hole.
What type of terminals are used to connect wires?
Spring clamps are a newer alternative to screw clamps and are generally used for relatively small wires. Push-in terminal blocks: Push-in terminal s allow you to connect a wire simply by inserting it.
What is a screw clamp?
Screw terminal: Screw clamp terminals are the most common type of connection method. The wire or conductor is simply pressed against the conductor strip in the block by tightening the screw. Screw terminals accommodate a very wide range of wire or conductor sizes.
What is a terminal block?
Terminal blocks are modular, insulated blocks that secure two or more wires together. Terminal blocks are used to secure and/or terminate wires and, in their simplest form, consist of several individual terminals arranged in a long strip. Terminals are useful for connecting wiring to a ground or, in the case of electrical power, ...
What are terminal blocks classified according to?
Terminal blocks can be classified according to their structure as well as device type.
What is contact in terminal blocks?
When discussing terminal blocks, the term "contact", also known as a position, way, or pole, refers to a wire attached to the block. The number of contacts is an important specification when considering a product, as a buyer is required to match this number with the number of wires necessary for a project or application.
Why are stackable terminal blocks mounted next to each other?
Stackable terminal blocks can be mounted next to each other to save space; they are typically DIN rail mounted devices.
What are terminal blocks grouped by?
Terminal blocks may also be grouped by application or type of device they connect.
What is dual level terminal block?
Dual level terminal blocks have two levels of contacts; this arrangement saves space and simplifies wiring. Multi-level products may use a bridge to connect one contact level to another for increased circuit flexibility.
What is a disconnect block?
Disconnect blocks allow a circuit to be easily disconnected using a knife switch and without removing wires. They are also known as switch blocks.
What are terminal blocks?
Terminal blocks are components that feature an insulated outer frame that houses terminals which join two or more wires/cables. A terminal blocks only purpose is to securely join two or more wires together.
What are the different types of terminal blocks?
The screw-in terminal block is one of the most common types of terminal blocks that are found in electrical systems and panels. They feature an insulated body with screws that are used to hold the terminated wires in place.
Where are terminal blocks used?
Terminal blocks are used in electrical panels and systems to quickly and safely allow for the connection of wires to certain points of a circuit. They make wiring modifications extremely easy as they allow for wires to be connected/disconnected easily.
How to mount terminal blocks
Mounting terminal blocks depends on what type of terminal block you have. Some terminal blocks are din rail mounted, this means that they are slotted at the back to clip onto din rail that is normally used in electrical panels.
How to wire terminal blocks
Terminal blocks are really simple and easy to use, to wire them all you need to do is the following:
Are terminal blocks safe?
Yes, terminal blocks have many different benefits and can increase the safety of an electrical system/panel. They can do this by grounding, isolating and protecting other components within the electrical system.
Can you cut terminal blocks?
Yes, but this depends on what type of terminal block you have/are using. Some terminal blocks cannot be cut as they come as single blocks. Other terminal connector blocks come in a strip. You can cut the desired quantity off the strip and use them as single connector blocks.
Structure Type
These blocks connect two wires together. The block is also called a single feed terminal block. It has one input and one output contact.
Device Type
Grounding terminal blocks mechanically and electrically connect wires to the DIN rail through a conducting clamping foot. In this way, the DIN rail functions as a ground bus bar. Grounding terminal blocks are in green and yellow per international standards.
Screw terminals
The screw on the terminal block is used to tighten the wire or conductor inside the terminal block.
Spring Clamp
The spring pressure is used to retain the wire properly clamped. It is generally used for lower rating applications, however, for power applications, the spring clamp terminal blocks are available in the market.
Push-in terminal blocks
With Push-in connection technology, you can connect conductors from 0.25 mm² easily – both directly and without tools just by inserting the screwdriver into the release hole. The special contact spring allows easy insertion and guarantees a high level of contact quality.
Insulation Displacement Connector ( IDC )
IDC is an electrical connector that connects conductors of insulated cable. There is no need for stripping of the conductor insulation.
Barrier Terminal Block
Barrier terminal block is used in power system. A spade or ring terminal is attached to the wire and then inserted into a bolt and tightened with a nut on the terminal block.
What is terminal block?
Terminal blocks are one variety of connector component for joining sections of electronic circuits in industrial applications. They include electrically conductive assemblies having wire-securing receptacles — all encased in monolithic plastic housing. Some terminal blocks have contact pads or legs for connection to PCBs, ...
What happens when you select a terminal block?
When selecting a terminal block, current ratings are paramount. Excessive current through a terminal block can induce overheating and failure. Voltage is usually less of an issue, but still a key terminal-block parameter: Excessive voltage (while rare) can induce dielectric breakdown and current leakage between adjacent blocks.
What is a pluggable terminal block?
Pluggable terminal blocks have wire and cable input receptacles as expected — as well as a male plug output to insert into a mating socket. Such terminal blocks are indispensable for hot-swapping connections during inspection and service.
What is an interface block?
In fact, the job of an interface block is to connect an array of wires from a power component to pre-engineered cable (sporting a specialty connector) from a controller or other low-signal component. For example, one common interface might accept a 37-pin D-sub plug and connect it to a 38-position terminal block that holds the wires in their terminals with push-in contacts. Recall that the D-subminiature connector is named for its distinctive D-shaped metal plug shield … perhaps most familiar for its inclusion on older consumer-printer cable ends.
What is dead front wire?
Some safety-featured styles include dead-front wire receptacles that recess conducting elements into the plastic housing. Other styles have a stepped (tiered) design to save space and make it easier to access all wire receptacles even if one section of the block is already wired.
What is tubular clamp contact?
It is called tubular clamp contact when a flat pressure plate on the screw end clamps the wire … which is a setup that’s useful for finely stranded wire. Terminal blocks with barrier terminals also employ screws to hold conducting wires and cables fast.
What is a terminal block?
Terminal blocks —also referred to as terminal connectors, connection terminals, or screw terminals—are used in a wide array of applications where electrical systems need to be safely connected.
What is a single piece terminal block?
Single-piece terminal blocks are constructed in a way that all poles are contained in a single housing. These are typical for pluggable housings where it would not be feasible to have multiple pieces. Other uses include high current or high temperature versions where a single housing would be stronger.
How does a PCB mount work?
Often referred to as Eurostyle or wire-to-board terminal blocks, PCB mount terminal blocks work by inserting bare wires into the module where a clamp secures the wire in the housing. The housing is then soldered to a PCB in common footprints. PCB mount terminal blocks can be single, dual, or multi-level modules.
What is feed through terminal block?
Feed-through terminal blocks are used to connect two wires together for wire-to-wire connections. This terminal block type has one input and one output contact where two distinct wires are fed into opposite sides of the housing. Like PCB mount versions, these can also be single, dual, or multi-level modules.
What happens if you run a terminal block at high current?
Operating at too high of a current can cause overheating and damage of the terminal block, leading to major safety concerns. It is best practice to use a terminal block that is rated for at least 150% of the max current that is expected in the system.
What is the current rating of a terminal block?
The current rating is based on the conductivity of the terminals, cross-sectional area, and the corresponding heat rise. Operating at too high of a current can cause overheating and damage of the terminal block, leading to major safety concerns. It is best practice to use a terminal block that is rated for at least 150% of the max current that is expected in the system.
How many poles are in a terminal block?
The number of individual circuits within the terminal block is also known as the pole count. This can be as few as a single pole, and as high as 24 poles, based on how many individual circuits are needed in the specific application.