Load Fault Monitoring in Bakery Production
A bakery ordered and took delivery of a tanker of flour, only to find that not all the flour would fit into the silo it was intended for. It was discovered that one of the load cells fitted to the silo had been severely damaged when a fork lift truck had hit the structure several weeks earlier. Returning the un-used flour back to the depot was a cost bourne by the bakery, however the situation could have been much worse. If the damaged load cells continued to take the incorrect weight reading of the silo, there could have been less flour in the silo than the bakery actually thought. The bakery would have run out of flour which would have stopped production, resulting in thousands of pounds of lost revenue to the bakery in down-time.
The Problem:
When two or more load cells are used in a single structure for weighing, the result is reliant on each load cell contributing the correct electrical signal for the force applied to it. Should a load cell or its cabling fail, then the indicated weight of the associated instrument will be incorrect, causing quality, safety and inventory issues.
The Solution:
The LCI Load cell junction box & fault monitoring alarm is an intelligent junction box for fault monitoring of up to four load cells. It is directly powered from the instrument that is providing the measurement as it scavenges power from the load cell excitation voltage, normally 10 Volts. The LCI has the same functionality as a summing junction box, but also provides individual measurements and integrity checks on each of the connected load cells and its cable. Should a fault condition arise, an alarm relay contact is used to warn of probable measurement failure. The display indicates which cell or cells are at fault allowing quick diagnosis and repair to be carried out.
The LCI performs the following checks:
- Open circuits on any load cell cable
- Short circuits on any load cell cable
- Excitation voltage error on any load cell
- Internal load cell fault such as bridge imbalance
- Load cell out of pre-set balance range where one cell is reporting more load than another
- Load cell out of range where one load cell is reporting greater or less than what is expected
The easy-to-use configuration and display allows the device to be used to aid installation as the individual mV/V and total mV/V can be displayed.
Products used in this application:
