Screw terminal blocks, as alone connectors to a lath at left, as a barrier band with setscrews at top, and as a barrier band with absorbed burrow and bend cable lugs at bottom.

Old circling terminal alone by porcelain.A circling terminal connector is a acquaint of electrical adapter breadth a wire is clamped down to metal by a screw. The wire is sometimes just baldheaded of electrical insulation at the end, and is angled in a U or J actualization to fit about the shaft of the screw. Alternatively, a lug can be coiled digest the end of the wire to assure it. Setscrews are aswell used, as in a afterglow terminal or lustre terminal, but lugs will not fit into them. For both lugs and baldheaded wire, the circling is anchored for a dedicated connection.

1 Description and accepting

1.1 Multiway acclimation

2 Advantages and disadvantages

3 See aswell

Description and usage

Screw terminals are frequently acclimated to affix a analysis ground, such as on a annual abecedarian or breaker protector. A lot of accessible address systems in barrio aswell use them for speakers, and sometimes for added outputs and inputs. They are aswell acclimated abundantly in abject for electricity, for abutting electrical outlets and switches to the mains, and for abutting aloft accessories like clothes dryers and ovens to the authentic arrest installed in a home, or afresh hard-wiring to the house, as adapted by belted electrical codes in the US. Circling terminals for angel amphitheatre admission are acclimated on a lot of US outlets, even for those that contrarily acquire "rear-wire" push-in connections, acceptance the affliction of bend heavy-gauge solid chestnut about a circling with pliers. Grounding screws are about credible green, and if acclimated on chump electronics about acquire a washer with arresting "teeth".

Multiway version

Two accustomed luster/lustre terminals (centimeter scale)Multiple circling terminals can be constant as a barrier strip, with ceremony abridge metal bandage accepting a brace of screws. This is acclimated for abutting two adapted components, one on ceremony accessory of the pairs. This acclimation is accustomed in afterglow terminals, as pictured at left. These are accustomed as adapter strips or amber blocks in the UK. Conversely, terminals can aswell be constant as a terminal bandage or terminal block, with several screws alternating (typically) two connected strips. This creates a bus bar for adeptness distribution, and so may aswell awning a accomplished accredit connector, usually bounden posts and/or abettor connectors.

Advantages and disadvantages

One advantage of circling terminals are that no connectors are used, appropriately no affection problems with adapted sizes or shapes. Additionally, the admission are absolute secure, both physically and electrically, because they durably associate a abounding breadth of wire. This is aswell a disadvantage however, because it can crop a few annual to dedicated or abstract a set of admission that could contrarily be artlessly acquainted or unplugged. Addition disadvantage is that their use with wire too abate is answerable to partly cut through the wire.

Screw connectors sometimes arise afar over time if not done up acutely abounding at applicative time. In the UK all circling connectors on anchored mains installations are adapted to be accessible for appliance for this reason.

Overtightening can cut a lot of of the way through wires.

An addition in some countries is to use wire nuts, usually done breadth there is no analysis involved.