On the bottom side of the relay box, there is a plastic gap where a flat-headed screwdriver can be fitted. Place and push the screwdriver inside the gap and at the same time pull the cover away from the wall mount. The information in this. This handbook covers the code of practice in protection circuitry including standard lead and device numbers, mode of connections at terminal strips, colour codes in multicore cables, dos and donts in execution. From troubleshooting to fixing common issues, we've got you covered. more Sound or visuals were significantly. How to (not) Open a Relay: So, I was desoldering relays and one didn't work. So h. statement of guaranteed properties.