WARNING: Only qualified electricians should wire mains voltage. Disconnect power before opening the terminal cover.
Below is a typical terminal assignment (check your specific manual on page 10–12):
Terminals 1–3 (Power and Output):
Terminals 4–5 (Alarm Output):
Terminals 6–8 (Sensor Input):
Quick wiring check:
If you can’t find the voltage rating, start low. Connect a 5V USB charger. If nothing lights up, try 12V. If it smells like ozone, you went too high. (Seriously, don't exceed 24V if you aren't sure).
If the official manual is unavailable in your language, user communities have created translated or simplified versions. Check:
Warning: Community manuals may contain errors. Always verify calibration steps against the original factory document. zn-401s manual
| Code | Meaning | Likely Fix | |------|---------|-------------| | E1 | Overload (weight exceeds max capacity) | Remove weight immediately | | E2 | Underload (pan missing or broken sensor) | Reinstall pan or service sensor | | E4 | Calibration error | Repeat calibration with correct weight | | Lo | Low battery (battery version only) | Recharge or replace batteries | | Err 5 | Stability timeout | Place on vibration-free surface |
Refer to your official manual pages 5–9 for the exact parameter sequence. Below is the standard process.
The ZN-401S is a workhorse, not a thoroughbred. It was built to be cheap and functional, not to come with a leather-bound user guide.
If you need the manual to set the time: Try the long-press method. If you need the manual to wire it: Look for the relay pins (NC/C/NO). If you need the manual to complain to support: You are probably out of luck. Terminals 4–5 (Alarm Output):
Did you finally figure out which variant of the ZN-401S you have? Let me know in the comments. If you found the actual PDF, please post the link—you’ll be a hero to the next poor soul who searches for this thing.
Happy wiring, and don't let the magic smoke out.
Flip the board over. Look at the silkscreen (the white text on the green circuit board).