Chapter 5
Maintenance and Repair Notes
ITW Dynatec
UFD Applicator, Manual 40-43, Rev. 6.16
Page 43
5.9 Testing of Resistance
Testing Resistance of Heater Cartridges
WARNING
Heed all security advices given in Chapter 5.1.
Maintenance and repair work is only permitted for skilled personnel!
1. Stop all motors.
2. Turn the ASU OFF or disable the Applicator and preheater zones at the control panel.
Disconnect all electrical cables from the Applicator.
3. Relieve the adhesive pressure by following the instructions under Chapter 5.4
“Relieving Adhesive Pressure”.
4. Unplug the electrical cable from the adhesive supply hose or extension cable to
expose the pins in the cable.
5. Use the schematics in Ch. 9 to determine the correct pins used to measure the heater
resistance. Compare the reading with the values given in the charts below.
Service Block Heaters
The service block of the Dynafiber UFD Applicators contain three 10mm heaters wired in
parallel. The parallel resistance values of these heaters is listed below:
Applicator Model
Parallel Resistance
Minimum Maximum
UFD050 Series
115.8
141.9
UFD075 Series
98.7
120.7
UFD100 Series
86.9
106.4
UFD150 Series
57.9
70.9
Air Preheater Heaters
The air preheater contains three or more heaters wired in parallel. One heater, located at
the front of the preheater, is 8mm diameter. The remainder of the heaters, located in the
spiral tubes at the rear of the preheater, are 10mm diameter. The number of 10mm
heaters depends on the width of the Applicator.
The parallel resistance values of these heaters is listed below:
Applicator Model
Standard Models
Parallel Resistance
Minimum Maximum
Slim Line Models
Parallel Resistance
Minimum Maximum
UFD050 Series
86.9
106.4
129.6
158.4
UFD075 Series
57.6
70.4
86.9
106.4
UFD100 Series
43.3
53.2
64.8
79.2
UFD150 Series
43.3
53.2
43.3
53.2
If one of the heaters is not functional, the parallel resistance as measured at the contact
pins will be
higher
than the range given in the chart. To determine which heater is not
functional, remove the cover plate and test each heater independently.