ABB PFEA 113 User Manual page 97

Tension Electronics PFEA113, User Manual
Section 6.7 Fault Symptoms and Measures
Table 6-1. Fault Symptoms and Measures
Fault symptom Measures
No signal when load is applied 1. Check that cables to the electronics are
correctly connected.
2. Check that the load cells are connected with
correct polarity. If not, the load cell signals cancel
out each other. This is displayed on the operator
panel as described below:
a. The sum signal (A+B) or (C+D) is low
b. The difference signal (A-B) or (C-D) is high
c. The output signal of the individual load cells
have opposite signs (polarity) when a force is
applied on the middle of the roll.
To check load cell signal polarity, see Section 3.9
Checking Load Cell Signal Polarity.
For connecting the load cells to give positive
signals for increased web tension, see cable
diagram for the installed load cell type.
3. Switch off the tension electronics and measure
the cable resistance in the load cell signal circuit
between terminals:
X3:1 - X3:2,
X3:3 - X3:4,
X3:5 - X3:6
X3:7 - X3:8.
a. The resistance is > 25 ohms:
Check cabling and load cells.
b. The resistance is < 25 ohms:
Check the mechanics.
3BSE029382R0101 Rev C 6-5