SUN SAFES MFG. CO. KOREA
METACEL MC-20 / MC-40
User Manual
Read the complete opening and setup instructions for your PR, AL or C1 safe, including passcodes, fingerprints, batteries and troubleshooting.
Before changing settings
Keep the door open while setting a passcode or registering fingerprints. After changing batteries, confirm that the safe works correctly before closing the door.
1. Models, first use & safety
This page covers MC-20PR, MC-40PR, MC-20AL, MC-40AL, MC-20C1 and MC-40C1. Identify your model before using the keypad and port illustrations.
First-use checklist
- Locate START, the fingerprint sensor, the inside S memory button and the battery case.
- Check the battery supply. Open the safe with 123456 if the factory passcode is still in use.
- Set your personal passcode using the setup sequence displayed by your safe. The manual provides both 1-user and 2-user instructions.
- Check the new passcode with the door open before closing the safe. Register fingerprints if required.
Safety precautions
- Keep fingers and objects clear when opening or closing the door. Keep children away.
- Take care around the safe's edges to avoid injury.
- Take care when moving or installing the safe. Ask a professional for assistance when needed; improper handling can damage floors or furniture.
- Secure the safe firmly to the floor during installation. Ask your installer or purchase store about the correct fixing method for your model.
- Do not place fragile glass or ceramic objects on top of the safe, where they may fall.
- Use a dry, flat surface so the door can close correctly.
Reference: PDF page 1 and PDF page 2 (printed pages 01–02).
2. Parts & keypad layouts
The inside layout identifies the main body, tray, shelf on MC-40 models only, S memory button, door sensor, LED light, battery case, alarm and locking bolts.
PR keypad
AL / C1 keypad
- LCD display: shows prompts, confirmations and faults.
- Touch keypad and START: used to enter and confirm passcodes.
- Fingerprint sensor: used during fingerprint registration.
- USB-C port: supplies emergency power when internal batteries are depleted. Its location varies with the layout.
- S memory button: inside the door; used for passcodes, fingerprints and volume.
- B and W: marked not in use in the manual.
- Master-key hole: shown as an optional feature in the PR layout. The supplied manual does not give a key-opening procedure; contact the purchase store for instructions for your fitted option.
Reference: PDF page 2 (printed page 01).
3. Opening the safe
- Press START.
- Enter your current passcode. The factory passcode is 123456.
- Press START again to confirm.
- Pull the door open.
For privacy: press START twice to hide the passcode display. To disable the function, press START twice again.
CH-03 or Err-03 means the passcode is incorrect. Five incorrect entries trigger a 3-minute alarm. Enter the correct passcode or wait for that alarm to stop.
If the batteries are depleted, see USB-C emergency power. If you have forgotten the passcode, the manual directs you to the store where you purchased the safe.
After use, close the door carefully and check that it is secured before leaving the safe.
Reference: PDF page 2 (printed page 01) and PDF page 4 (printed pages 05–06).
4. Passcodes: 1-user / 2-user mode
The manual provides two setup sequences. Follow the prompt shown on your safe after pressing S. It does not assign these sequences to particular PR, AL or C1 models or explain how to switch modes.
Keep the door open throughout setup. Choose a 4–20 digit passcode and check that it works before closing the safe.
1-user mode
Use this sequence when the display goes from CodE directly to new-passcode entry.
- Open the door and press the S memory button inside the door.
- When CodE appears, enter the new 4–20 digit passcode and press START.
- When AgAin and the dash prompt appear, enter the same new passcode again and press START.
- Check for USEr_1, which confirms that the new passcode has been set.
- Test the passcode with the door open.
2-user mode
Use this sequence when CodE is followed by USEr_, prompting you to select a user.
- Open the door and press the inside S button.
- Wait for CodE, then USEr_.
- Select 1 for User 1 or 2 for User 2, then press START.
- Enter the new 4–20 digit passcode and press START.
- At AgAin, enter it again and press START.
- Check the confirmation: USEr_1 or USEr_2, matching the selected slot.
- Test the new passcode with the door open.
| 2-user slot | Selection | Confirmation |
|---|---|---|
| User 1 | 1 → START | USEr_1 |
| User 2 | 2 → START | USEr_2 |
If setup times out, repeat the procedure promptly. The troubleshooting guide specifies entering the passcode within 5 seconds. Contact the purchase store if you cannot identify the setup sequence or a keypad/button fault prevents completion.
Reference: PDF page 2 (printed page 02) and PDF page 4 (printed page 06).
5. Register or delete fingerprints
Register a fingerprint
- Open the door.
- Hold the inside S button for 3 seconds until SEt appears.
- Briefly press S once more to display FIngEr.
- Press 0 to register.
- Scan the fingerprint three times. Up to 10 fingerprints can be registered.
Delete one fingerprint
- Open the door and hold S for 3 seconds until SEt appears.
- Briefly press S once more to display FIngEr.
- Press 1 for deletion.
- Enter the ID number of the fingerprint you want to delete.
Delete all registered fingerprints
This removes every registered fingerprint. In the deletion sequence, press the S button instead of entering an individual ID number. See the original sequence on PDF page 3.
Reference: PDF page 3 (printed page 03).
6. Batteries & USB-C emergency power
Safe batteries: four AA alkaline
Use four new 1.5 V AA alkaline batteries in the safe's battery case. Check the marked battery direction. Correct insertion is confirmed when good appears and a beep sounds.
- With access to the inside battery case, replace depleted batteries with new ones of the specified type.
- Check their direction and the good startup confirmation.
- Confirm that the safe works properly before closing the door.
Use new batteries. The manual warns of leakage when used batteries are fitted. Remove batteries if the safe will not be used for a long time.
Replace batteries immediately when
- The display shows Lo_bAt.
- The door fails to open when OPEn appears after passcode entry.
- good appears with “beep beep” after passcode entry.
- The screen does not turn on when START is pressed.
- The touch-button display is faint, there is no response, or the safe malfunctions.
The context of “good” matters: after fitting batteries it confirms correct insertion; with “beep beep” after passcode entry, it is a battery-replacement warning in the manual.
Supply emergency power through USB-C
When internal batteries are depleted, the manual identifies a USB-C port that can supply power for opening the door. Locate it using the keypad layout for your model.
- Connect an emergency power accessory specified for your safe to the USB-C port.
- Follow the normal opening sequence: START, current passcode, START, then pull the door open.
- Replace the internal batteries and test normal operation before closing the door.
The alarm uses separate batteries: three 1.5 V AAA batteries, rather than the safe's four AA batteries.
Reference: PDF pages 2–3 (printed pages 01, 03–04).
7. Privacy, keypad lock & volume
Security mode: hide the passcode display
Press START twice to hide the passcode display. To disable this function, press START twice again.
Keypad lock mode
| Action | Procedure |
|---|---|
| Activate | Hold START for more than 10 seconds, until Act appears. |
| Deactivate | Hold START for more than 3 seconds, until dEAct appears. |
While active, keypad input displays Act. Deactivate it before entering a passcode normally.
Adjust volume
- Open the door and hold S for 3 seconds until SEt appears.
- Briefly press S twice more to display VoL.
- Select a level from 0 to 7.
- Press START to confirm.
Reference: PDF page 3 (printed page 04) and PDF page 4 (printed page 05).
8. Using the alarm
The separate alarm unit uses three 1.5 V AAA batteries. Use the alarm's own ON/OFF switch to control it.
- Check that the three AAA batteries are installed correctly.
- Turn the ON/OFF switch ON.
- The unit becomes ready 10 seconds after switching on.
External impact or tilting triggers the alarm, specified in the manual as 120 dB. A light sensor disables it when the door is open.
The passcode-error alarm is described separately in troubleshooting: after five incorrect passcodes, enter the correct passcode or wait 3 minutes for that alarm to stop.
Reference: PDF page 3 (printed page 04) and PDF page 4 (printed page 06).
9. Display message guide
| Message | Meaning / next step |
|---|---|
| CodE | Passcode setup. Continue with the 1-user sequence, or select a user if USEr_ follows. |
| USEr_ | 2-user setup: select 1 or 2, then START. |
| AgAin | Enter the new passcode again and press START. |
| USEr_1 / USEr_2 | The corresponding user's passcode has been set. Test it with the door open. |
| SEt | Settings mode. Continue with the fingerprint or volume sequence. |
| FIngEr | Fingerprint setup: 0 to register; 1 for deletion. |
| VoL | Choose volume 0–7, then START. |
| Act | Keypad lock active. Hold START for more than 3 seconds to deactivate. |
| dEAct | Keypad lock deactivated. |
| CH-03 / Err-03 | Incorrect passcode. Enter the correct passcode. |
| Lo_bAt | Replace the safe's four AA alkaline batteries with new ones. |
| OPEn but door will not open | Listed as a reason to replace batteries. |
| good | After battery insertion, with a beep: correct insertion. After passcode entry, with “beep beep”: replace batteries. |
Reference: PDF pages 2–4 (printed pages 02–06).
10. Troubleshooting
No response when START is pressed
- Replace depleted batteries with four new 1.5 V AA alkaline batteries.
- Confirm correct battery direction.
- If keypad lock is active, hold START for more than 3 seconds until dEAct appears.
- If there is still no response, contact the purchase store; a circuit fault may require service.
The alarm continues after incorrect passcodes
Five incorrect passcode entries trigger the alarm. Enter the correct passcode or wait 3 minutes for that alarm to stop automatically.
CH-03 or Err-03 appears
The passcode is incorrect. Enter the correct one using START, passcode, START. If you have forgotten it, contact the store where you purchased the safe.
The passcode cannot be changed
Repeat the appropriate 1-user or 2-user setup sequence. Enter the passcode within 5 seconds, as instructed in troubleshooting. For a keypad or button fault, contact the purchase store.
Lo_bAt or Act appears
Lo_bAt: replace the safe batteries. Act: hold START for more than 3 seconds until dEAct appears to deactivate keypad lock.
The safe will not open after battery depletion
Use the USB-C emergency power facility with the correct accessory, then follow the normal passcode sequence. This supplies power; it does not replace the need for the current passcode.
Forgotten passcode
Contact the store where you purchased the safe, as instructed in this manual.
Reference: PDF page 3 (printed pages 03–04) and PDF page 4 (printed page 06).
11. Frequently asked questions
Does this page also cover MC-20C1?
Yes. The original manual includes both MC-20C1 and MC-40C1, along with the PR and AL versions listed at the top of this page.
Should I use the 1-user or 2-user passcode instructions?
Follow the prompts after pressing the inside S button. If CodE is followed by USEr_, select User 1 or User 2. If it proceeds directly to new-passcode entry, use the 1-user sequence. The manual does not explain switching between the modes; contact the purchase store if you need this confirmed.
How many times do I scan a fingerprint?
This manual specifies three scans per registration, with a maximum of 10 registered fingerprints.
How do I disable hidden passcode display?
Press START twice again, as specified in the original manual.
Which batteries go in the safe and alarm?
The safe uses four new 1.5 V AA alkaline batteries. The separate alarm uses three 1.5 V AAA batteries.
Where is the USB-C emergency power port?
Its location varies with the keypad design. Use the PR or AL/C1 illustration under Parts & keypad layouts.
How do I use the optional master key?
This manual shows an optional master-key hole in the PR layout but does not give a key-opening procedure. Obtain instructions for your model and fitted option from the purchase store.
Why does the PDF include an MC-15 protective-film note?
The supplied PDF is a shared manual whose cover also lists MC-15 models. Its note about the decorative panel coming off during protective-film removal is specifically labelled MC-15; it is not an MC-20/40 panel-removal procedure.
12. PDF manual & support
Keep the original illustrated manual
Download the original 4-page English PDF, version 202601. It includes spreads with printed pages 01–06.
Need assistance?
Contact the store where you purchased the safe for a forgotten passcode, circuit/keypad/button fault, confirmation of passcode mode, optional-key instructions or the correct emergency power accessory.
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