Do I really need to use a summing Junction Box?

Using a summing junction box is not absolutely required, but it is strongly recommended. If you try to connect one or two load cells directly to the weight controller there should not be a problem. If you try to connect more than two load cells then the connection becomes more difficult and the chances of having a loose, intermittent or poor connection increases dramatically.

If you want Integrated Technician (IT) functionality and are using more than one load cell, an IT summing junction box is required to test individual load points.

Some of the benefits of utilizing a summing junction box include:

1. An organized and designated way to terminate your load sensor and weight controller cables together, and a lower chance of a bad or intermittent connection.

2. Quick disconnect connector for isolation and troubleshooting load cells.

3. Optional INTEGRATED TECHNICIAN® (IT) Junction Box allows troubleshooting from certain Hardy Instruments PLC module, weight controller or indicator front panel, or from the internal web browser or communication network (where applicable) without having to open the junction box.

Any controller using 10vdc excitation cannot use the Integrated technician summing junction box, including the HI 1771WS, HI 220xLT, HI 2160RC and the older HI 2151/20WC. See related answers on Integrated Technician.  The HI 3010, HI 2080-WS, and the HI 200DNWM do not have programming for Integrated Technician.  The HI3010 can be equipped with Smart Diagnostics.

Hardy’s summing cards can be ordered in a NEMA 4 or 4X metal box to shield EMI/RFI or a fiberglass box for resistance to harsh chemicals. The Hardy Process Solutions INTEGRATED TECHNICIAN® junction box can be used with non-C2® load cells, but Hardy’s specialized C2® Cable should be used to ensure the diagnostic routines run reliably.  The C2 wires provide communications and control path and is a specialized cable for that purpose.