Yesterday and Monday was the most tiring and stressful days of my internship so far. But the "rain" has to stop eventually and up comes the sunshine. 

There's NO fieldwork today so not much movement and thinking is involved. But still, I have plenty of work to do in the office like soldering the potentiometer, test the customer's voltage regulator device, reorganize the toolbox and ponder about yesterday's Sungai Besi factory problem. Initially we plan to revisit the factory for the third time today but since there's some conveyor problem at the factory, we cannot go there until next week.

In the morning...aaarrggghhh!! I can't recall what I did this morning!! Should have written it down! Lucky I took a picture of a machine. The machine is actually a motor and an inverter bundled together in one package. It was sent to us because the inverter was damaged by some fluid that has entered into the inverter and short-circuited the circuitry inside. The motor is fine so only the inverter is replaced with the exact same model. Below is the picture of the whole machine.

Wired the power cables, motor cables and mounted the inverter onto the base of the motor. After everything is tight, I powered up the motor and inverter for a short test run with the supervision of Mr. James. We only change one program code of the inverter according to the instructions in the motor manual. Everything is running fine so I switched off the machine and prep the machine so that it is ready to be collected by the customer.

After lunch me and Mr. James pondered about the Sungai Besi factory problem. Recall that the problem is that the inverter controlling a motor is unable to deactivate itself after all of the switches on it is turned off. The off signal is coming from an array of relays and a PLC module. Mr. James gave me a similar inverter to simulate the problem. He thinks that the problem lies somewhere in the wiring or relay of the control panel back at the factory so he suggests that I isolate the switch signals with a relay. Great, how do I connect them? I took the challenge and Mr. James gave me some time for me to figure out the terminal connections.

After a few tries, I managed to find the correct terminal connections. And I learn how a relay works too! Now the signal from the control box has to go through the relay before reaching the switch terminals on the inverter. If the switch is on, it will activate the relay and the relay contact will then pass the signal to the inverter thus activating it. This is how the terminal connection looks like:

The "rain" of work have finally ceased, for now. Not sure what's in store for me tomorrow but I better prepare myself and get sufficient rest while I can. The rain can re-start at any moment and the next one can be worst than the previous one