Cross-Wire Monitoring

What is a Cross Circuit?

A cross circuit is a signal that has gone the wrong way along two parallel wired cables or on a crossing point of two cables. The signal does not travel along its intended cable but jumps into the neighbouring cable and creates an interference there. Cross circuits are hints regarding failures in the insulation or design. Another cause for short circuits can be voltage peaks.

Why is it important to recognize Short Circuits?

Each electric interference can grow into a major problem. Even minor malfunctions lead to mishandling or faulty reactions of the control unit. The worst case would be electric disturbances leading up to cable fires which would expand into the entire system. Therefore a requirement for construction of electric systems is single-failure-proof. This means that one single error can not lead to failure of the entire system. Automatic recognition of shortages and cross circuits is an important part of setting up a single-failure-proof system.

What is Cross Circuit Detection?

The cross circuit detection is a signal interpreter that checks whether an incoming signal is the desired or expected signal or an interfering signal. A detected cross circuit usually initiates an emergency stop. The installation of cross circuit detection into a complex electric system is fairly complicated. On the other hand, a cross circuit can be detected quickly and therefore fixed as soon as possible. This increases the budget required for a system but it highly increases the fault tolerance.

How does Cross Circuit Detection work?

The task of cross circuit detection is to interpret an incoming signal correctly. The signal interpreter does so by using a target/actual comparison. There are several possibilities to do so. If, for example, a relay is open, the cable behind it can not transport any power. If power is detected on that cable anyway, it can be concluded that there is a cross circuit. Another possibility of cross circuit detection is checking synchronies of signal contacts. The signals of cross circuits are not transported in their entirety into the next cable but only partially. One part remains in the original cable and reaches the intended target. The result is the split signal simultaneously reaching the target as well as the not intended position. Cross circuit detection can be programmed in a way that detects suspicious incoming signals and reports them. Depending on the relevance of the error signal, the control unit can initiate an array of reactions. They can range from a simple error message to an emergency stop of the entire system. This prevents the error spreading and ensures the operational safety of the entire plant.

Installation of Cross Circuit Detection

The suppliers of electric components offer cross circuit detections. Often they are emergency stop buttons which are equipped with this additional functionality. This integration makes it much more comfortable and significantly simplifies installation of this important functionality. However, the installation of cross circuit detection remains a challenging task which should be done by electricity specialists. A system with sustainably installed cross circuit detection offers a maximum production availability and failure safety.