Some EQSS Overwatch kits receive their control signals from scissor control box LED display circuits.
Overwatch kits are engineered and adapted to reliably function as a safety cutout system. Various control signals are carefully considered and then the most reliable ones are chosen to be monitored by the Overwatch system. The panel LED lines are sometimes chosen as a reliable signal source and they also have the added benefit of being immediately visible (and thus are usable as a trouble shooting tool).
Therefore, if during an Overwatch installation test, some function is failing, please look at and observe all control box panel lights. If it's found that some light(s) are not illuminating (faulty control board), then this could be the cause of an Overwatch test failing.
Below is a generic schematic, illustrating the type of circuit being discussed in this Tech Doc:
In the schematic above, a connection is made for the Overwatch to monitor and sense a logic change. If a fault occurs at the logic chip that drives the transistor and LED, then the Overwatch will not sense a logic change and also the LED will not illuminate. This could be used effectively as a troubleshooting tool. So if the Overwatch is not sensing one of the signals from the EWP control box, then please observe and make sure first that all control box indicator lights are operational before raising EQSS support requests.