Rice Lake Contego-Hygienic Weigh Module Kits, Lateral Cable Outlet - Manual (Page 27)

Installation Manual Hygienic Weighing Module Contego®
Sartorius EN-25
7.2 Checks with Multimeter
7.2.1 Check Zero Output Signal of Load Cell
• Unload load cell.
• Disconnect the load cell measuring outputs.
• Check whether the output voltage without load is within the limits.
Type Zero output signal
D1, C3 0 mV ±0.02 mV/V
7.2.2 Checking the Strain Gauge Bridge of the Load Cell
• Do not exceed the test voltage.
• Check whether the values of the resistors are within the permissible limits.
Maximum test voltage Standard industrial 28 V DC
intrinsically safe version (PR …/…E) 25 V DC
Type Input impedance
(red core, blue core) Output impedance
(green core, gray core)
D1 650 Ω ±6 Ω 610 Ω ±1 Ω
C3 650 Ω ±6 Ω 610 Ω ±0.5 Ω
7.2.3 Checking the Insulation Impedance of the Load Cell
• Never apply the test voltage between the cores of the load cell cable (danger of destroying the load
cell).
• Insulate the load cell cores.
Maximum test voltage Standard industrial 100 V DC
Intrinsically safe version (PR …/…E) 500 V AC
Insulation impedance Core - housing >5000 M Ω
Core - screen >5000 M Ω
Screen - housing >5000 M Ω
7.2.4 Check Insulation Impedance of Connecting Cable
• Disconnect connecting cable and load cells.
• Insulate the cores of the connecting cable.
Insulation impedance Core - core ≥600 MΩ × km
Core - screen ≥600 MΩ × km