Cleveland Motion Controls ULTRA SERIES CARTRIDGE TRANSDUCER REV AA - Manual (Page 17)

MAN-70251 R EV . AA U LTRA S ERIES S TATIONARY S HAFT T RANSDUCER
P AGE 17 OF 18
4 T
ROUBLE
S
HOOTING
Safety should not be an afterthought. Before installing, servicing or calibrating review and follow applicable policies
and procedures to ensure worker safety. Machinery must be in a safe state and be aware of any additional hazards
that can arise when installing and calibrating higher force transducers.
The following table provides you with a list of typical issues that you may encounter and possible solutions:
If you are having this issue: Then:
Low Output Signal
The transducer may have too large a maximum working force (MWF) in relation to the
force to be sensed, or the wrap angle may be insufficient and is not able to generate an
optimum resultant force on the transducer.
Or
The transducer may be improperly orientated such that the transducer’s axis of
sensitivity is not aligned with the bisector of the wrap angle.
Or,
Check the amplifier to confirm that the signals from each transducer will combine
additively. Otherwise, the two signals will work against each other, and only
minute
differences between signals appear.
Wrong Polarity of Output Signal
Transducers may have been incorrectly oriented. Refer to Section 3.1 for proper load
direction. Alternately, change the signal sense by interchanging the white and black
transducer leads into the amplifier.
No Output Signal
Check to be sure that all connections have been made completely and properly.
Inspect the connecting cables for crimps or cuts.
Verify that the appropriate excitation voltage is being issued by the amplifier with the
load cells connected.
Disconnect the transducer output wires from the amplifier’s input terminals (to eliminate
any potential for accidental loading) and check the output signal using a voltage meter.
Check the transducer (refer to Section 4.1.1 - DC Resistance Check in this document).
Excessive Output Signal with Minimal or
No Load
There may be a high degree of misalignment of the transducers causing a severe pre-
load.
Or
The sensing guide roll assembly may be excessively heavy. The sensing guide roll
should not weigh more than ½ the maximum working force of the transducers in most
cases.
Or
The transducer may have too small a maximum working force for the application.
Replace with a higher maximum working force transducer or decrease the web wrap
angle.
Also,
Check cables and connectors for intended connections using an ohm-meter or
continuity checker. Inspect not only for continuity where expected, but also disconnect
pluggable connectors and check for unintended resistances (shorts) between
conductors.
Inspect the transducers for mechanical reasons why there is a reported overload.
Possibilities include, debris wedged in the transducer’s shaft seal area, or a roll shaft
bottoming inside the transducer body.
Poor Linearity
Check for mechanical reasons such as rubbing or binding that interferes with the force
being properly transmitted to the load cell.
Or
Your calibration efforts may have been conducted while either the transducer or the
amplifier was in a non-linear mode (i.e. under the effects clipping or saturation). Try and
recalibrate the amplifier using a lower force.
To determine whether the clipping is being caused by the transducer or the amplifier,
apply a series of intermediate forces and record the unamplified tension signal. If the
data demonstrates that the transducer is linear then, investigate the amplifier.