- ページ 7

産業機器 Siemens SIWAREX RのPDF 取扱説明書をオンラインで閲覧またはダウンロードできます。Siemens SIWAREX R 34 ページ。 Mounting units for sb series
Siemens SIWAREX R にも：取扱説明書 (38 ページ)

ページを印刷する

Edition 06/2009

1.3

System Configuration

In weighing technical systems one or more load cells are connected to a weighing

module for evaluation of the measured signal. Several load cells of a scales are

connected in parallel in a junction box to supply a common output signal.

Load cells may only be connected in parallel when they have the same

characteristic value, the same rated load and the same internal resistance.

ATTENTION

The total resistance in parallel connected load cells may not drop below the

minimum resistance specified in the technical data of the weighing module.

The maximum number of load cells that can be connected to a weighing module

depends on the total resistance of the parallel connected load cells. This must be

within limits of the weighing module specified for the load resistance. The length of

the lines and the data of other elements, e.g. Ex i-Interface, must also be taken into

account.

CAUTION

If several load cells are connected in a scales it cannot be determined whether

individual load cells are overloaded in the event of uneven load distribution.

The maximum cable length between the load cell and the weighing module can be

found in the technical data of the weighing module. For Ex applications the data of

the Ex-i interface must also be taken into account.

A shielded 6-wire cable, e.g.. Li2Y(ST)CY 6x0.75 mm

702-8AB or, for Ex applications, 7MH4 702-8AA must be used to connect the

junction box to the weighing module, to extend a load cell connecting cable or for a

cross-connection between two junction boxes.

Overloads should be avoided in the layout of load cells by creating a safety

reserve. The safety reserve for three application points should be 20%. In the case

of statically aspecific use of more than three application points, the safety reserve

must be at least 50% if it cannot be ruled out that the load is only resting on two

diagonally opposite load cells. The reason for this may be drops in the foundation

or improper assembly. Accidental overloads or overloads due to the process must

be taken into account or kept away from the load cells by overload protection

devices. Overloads are caused for example:

•

in the case of uneven load distribution as a result of attachments or tipping

mounds,

•

when rolling/pushing the load onto platform or rollway scales,

•

by hard setting down of the load,

•

by setting down the load in free fall,

•

when persons are leaning/standing on the scales,

•

by wind forces on the side of a silo facing away from the wind.

SIWAREX R Load Cells Operating Manual

A5E00159640

Technical Description

, Siemens order no.: 7MH4