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Screw Clamp Connection
The
most popular method of wire termination is obviously the
screw clamp type connection. In
comparison with all other terminations. It offers distinct advantage as listed below.
|
1 |
Suitable
for all cross-sections
and types of wires. |
|
2 |
Wires
can be connected without any special preparations. |
|
3 |
Vibration
proof termination is guaranteed. |
|
4 |
Wire
can be connected and disconnected simply by
using an ordinary screw driver. |
|
5 |
High
tightening torque because of cold forged
rolled
threaded screws. |
Most of
Connectwell terminals blocks are designed for screw clamp
wire connection.
The
steel clamping screw produces contact force. The steel
clamping yoke transmits this force by pressing the conductor
against the current bar. Current bar within the terminal
block is the conducting medium. It is made either from
electrolytic copper or 63/37 brass. Plating of tin ensures
excellent continuous contact and provides good protection
against corrosion. Even
the best electrical conductor materials are worthless
without the required contact force to press the connected
wire to contact surface of the current bar. For this reason,
clamping yokes and screws are made from steel. The steel
parts are zinc plated and additionally passivated by a
yellow chromate layer in order to achieve the highest degree
of corrosion resistance.
When
clamping screw is tightened, clamping yoke is pulled upward
pressing the wire against the current bar. Clamping yoke and
current bar are serrated. The serrations of current bar cut
through the oxide skin of the wire on tightening, provide
many contact lines. The serrations of the clamping yoke
increase gripping of wire. When wire is tightened, the
clamping pressure pulls top threaded surfaces of yoke. This
exerts extra high locking action on the clamping screw.
The
changes, if any caused by temperature variation are
effectively equalised by the elasticity of steel. This
provides an excellent vibration resistance.
Large
pressure areas on the current bar and the clamping yoke
prevent notching, which otherwise could lead to possible
wire fracture. The clamping yokes are made in various sizes
and shapes to accommodate wires of different cross section.
A flat clamping area ensures safe gripping of wire of
smaller cross section. Flange / Tail of the clamping yoke
prevents false entry of the wire underneath the yoke.
The
following characteristics make the Screw Clamp Connection
user friendly, versatile and sturdy :
|
1 |
Strong contact force, absolutely gas tight |
|
2 |
Very
low contact resistance |
|
3 |
An excellent vibration proof
protection against loosening |
|
4 |
A reliable electrical and
mechanical connection. |
|
5 |
Ease
of handling |
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