@Călin Sas This was in Zeeland 🤭 I can totally remember it. What I can’t remember is whether I’m the one who left them turned off. I know I left a few of them like that whahaha! But like you said, you learn from your mistakes, and that’s the beauty of it. Oh boy, I’ve learned a lot.

In my experience, the best way to perform an Isc measurement is to use a tool that is specifically designed for it. Personally, I use an HT meter. This meter allows you to safely connect the positive and negative leads and measure up to 1500 V DC. The reason I recommend this method is that when using a standard DC switch, there is a real risk of accidentally leaving the switch ON while performing multiple measurements. This can expose you to dangerous arcs or faults. The HT meter method eliminates that risk because the device is built to safely handle and control the short-circuit during the test. Reason I prefer an HT meter instead of a DC switch. 1. Designed specifically for Isc measurements HT meters have: • Built-in protection circuits • Current-limiting components • Anti-arc design • Automatic internal load management A DC switch has none of these. 2. No risk of leaving the switch ON When using a DC switch to create a controlled short: • You must remember to turn it OFF after each measurement. • If you forget, you could unintentionally leave the string shorted. • This can overheat the switch or cables and cause a dangerous arc. With an HT meter: • The short-circuit is controlled internally. • The meter automatically breaks the circuit when the measurement ends. • No external switch handling is required. 4. Safer handling of high-voltage DC 1500 V DC can produce: • Strong arcs • Instantaneous heating • Irreversible equipment damage HT meters like other meter similar to it are designed to withstand and safely manage these DC conditions. A normal DC isolator is not designed for repeatedly opening and closing high-current shorted circuits. 5. Faster and more consistent results HT meters: • Automate the testing process • Produce stable, accurate Isc readings • Reduce human error A manual DC switch introduces variability and potential mistakes. HT meter method (simplified) 1. Connect meter leads to the PV string (+ and –). 2. Meter automatically applies a controlled short.

Hi Calin. Thanks for your feedback it is mucho appreciated your. Other thing also how or what can be use to keep track of your tasks?