Why does my HI 1756WS get a -8 error when using the HI 215IT junction box?

I am using a HI 1756WS with a HI 215IT junction box and 2 Load Cells. When I try to do a hard calibration an error is shown (-8 = "HARCALFAILSCOUNTS"). If I connect the load cell to the HI 1756WS directly (bypassing the junction box) it works with no error. Why does my HI 1756WS get a -8 error when using the HI 215IT junction box?

If you get the -8 HARCALFAILSCOUNTS error when you run the Cal High command, it is an indication that the input from the load cell did not change or changed in the wrong direction from the input for the Cal Low command.

If you can hook up the load cell directly to the HI 1756WS module and it responds to weight changes, then the module is operating correctly. If you connect the load cell to the summing junction box and you do not get a response to weight changes, that would indicate the summing box is not working properly, or the wiring from the summing box to the module is not wired correctly.

Things to check:

With the HI 215IT summing box, you must ensure you have the C2® connections made from the HI 1756WS module. Without this connection the summing box will not function properly.

With a voltmeter, check the voltages to insure everything is wired properly. Check the voltages on the connection terminals from the load cells, on the summing box output terminals, and on the connector on the HI 1756 module. Voltages at all three locations should be:

Between +EXC and -EXC = +5vdc
Between +SEN and -SEN = +5vdc
between +SIG and -SIG = 0 to +15mv. This will vary with weight with a higher weight giving higher mv reading.

If the voltages for the load cells are correct but the output from the summing card is incorrect check the C2® connections between the module and the summing board.

If the voltages at the output from the summing box is correct but the input to the module is incorrect check the wiring between the summing box and the module.