Warner Electric C30 User Manual

C30 Single Range Tensioncells

P-2012-5
819-0405

Installation Instructions

Contents

General Information . . . . . . . . . . . . . . . . . . . 3

Installation and Operation . . . . . . . . . . . . . . . 7

Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . 8

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . 9

Recalibration . . . . . . . . . . . . . . . . . . . . . . . 10

Dimension Drawing . . . . . . . . . . . . . . . . . . 12

Warranty . . . . . . . . . . . . . . . . . . . . . Back Page

Failure to follow these instruc­tions may result in product damage, equip­ment damage, and serious or fatal injury to
personnel.

Warner Electric • 800-825-9050 P-2012-5

2

Description

W1 W2

Machine
Frame

C30 Series Tensioncell
Single Bolt Mounting

Damper

C-Flexure
Far Side

Mechanical Stop

L

oad

Plate

LVDT
LVDT

Core

General Information

Warner Electric Series 30 Type C Tensioncells
are force transducers especially designed to
measure and control web tension on continuous
strip processing lines. They are normally
installed in matched pairs at each end of a
measuring roll. (See Figure 1)

A Tensioncell consists of a unique combination
of two integral systems (one mechanical, the
other electrical) for converting the mechanical
force of strip tension into an electrical signal
which is directly proportional to the strip ten­sion.

Type "C" Tensioncells are intended for ROTAT­ING shaft installations. They are supplied with
self-aligning ball bearings to assure positive
alignment of the measuring roll. Type "C"
Tensioncells are supplied in matched pairs, one
to be mounted at each end of the tension meas­uring roll. Note that the cell marked "W2" is a
mirror image of "W1". The 'W2" cell allows for
thermal expansion of the rotating shaft. (See
Figure 1)

The Mechanical System

The mechanical system consists of a Patented
"C-Flexure Pivot Assembly" which incorporates
a mounting Base Block, frictionless elastic pivot
(or hinge), and Load Plate. (See Figure 2) When
a mechanical force is applied to the Load Plate,
the pivot permits its deflection toward or away
from the Base Block.

Figure 2

Self-Aligning Bearings in Tensioncell - Rotating Shaft

Figure 1

Warner Electric • 800-825-9050 P-2012-4

3

For our discussion here, deflection of the Load

Black - (2)
Red + (1)

Green (3)
Blue (4)

Input

Output

X Twisted Leads

A B

Oscillator Demodulator

P1

S1

S2

X

X

WhenSupplied

withCable

(1)Red +DC
(2)Black –DC

(3)Green –Signal
(4)White +Signal

CD

BAC

D

P

late toward the Base Block is defined as the
"Compression Mode", while the opposite is
defined as the "Tension Mode". Tensioncells are
designed to operate equally well in either mode.

The Base Block contains an integral Mechanical
Stop to limit the amount of deflection in either
direction, and a Viscous Damper to allow
control of the tensioncell response to rapid
changes in apparent tension loads. (See Page 3,
Figure 2)

The Electrical System

The electrical system consists of a Linear
Variable Differential Transformer (LVDT) which
converts the mechanical deflection of the Load
Plate into a useful electrical output signal. (See
Figure 2) The movable core of the LVDT is
mechanically coupled to the Load Plate by
means of the Core Adjust Assembly. (See Figure

3) This adjustment is factory set and is not
accessible.

Type "K" DC LVDT

As illustrated in Figure 4, a DC LVDT consists
of the following components:

• An oscillator network, which converts the
DC input voltage into a high frequency alter­nating current for exciting the primary coil
(P1).

• A Primary Coil (P1)

• A movable, permeable metallic core

• Two Secondary Coils (S1 and S2)

• A demodulator and summing network to
rectify and integrate the currents from the
Secondary Coils

Warner Electric • 800-825-9050 P-2012-5

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Figure 3

7

6

5

4

3

2

1

0

.

030” 0.0 .030”

3.5 V. Set Point

Tension

Compression

LVDT Output vs Deflection

O

u

t
p
u

t

V

o

l

t
a
g
e

Deflection

With Warner Electric LVDTs, the input and out-

Nominal

L

R

p

ut circuits are electrically isolated from each
other and from the mechanical structure of the
tensioncell. Thus, they may be used in "floating
ground" or "ground return" systems. This elimi­nates the need for extra circuit boards which are
required for most straingage loadcells.

Tensioncells are factory adjusted to provide an
offset voltage with no load applied (no deflec­tion). Using an input of 24 volts DC, the LVDT is
set to provide an output of 3.5 volts into a resis­tive load of not less than 100,000 ohms. The
voltage resulting from the maximum rated
deflection then adds to or subtracts from the 3.5
volt offset. This results in an output voltage of

3.5 to 6.5 volts in the Compression Mode and

3.5 to 0.5 volts in the Tension Mode. (See
Figure 4)

LVDT Output vs. Deflection Chart

Figure 4

While acceptable performance may be obtained
over an input voltage range of 6.0 to 30.0 volts
DC, the output voltage will vary in direct propor­tion to the input voltage. Because of this, the
use of a well regulated constant voltage power
supply is essential for accurate and repeatable
tension measurement.

In standard applications, where two Tensioncells
are used, the inputs may be connected in paral­lel allowing the Tensioncells to be excited from
the same power supply. The LVDT outputs are
then summed to obtain a signal representing the
strip tension and tare loads distributed across
the roll.

Warner Electric • 800-825-9050 P-2012-4

Description of Operation

The total resultant load per cell (RF) is calculated
by resolving all force vectors acting upon the
Tensioncell, with respect to the Loading Line (OL).
(RF) is the resultant of both TENSION and TARE
loads, PER CELL!! (See Figure 5)

(Figure 5)

5