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Intercom door release lock voltage

Updated: 22 October 2026

You already have a monitor kit, or you are about to order one, and the visitor still cannot open the communal door. Intercom door release lock voltage is the missing half of that purchase. None of the five amazon.co.uk kits in this comparison lists a strike or a maglock in the box. The unlock button is an output. The lock is a second product, and it has to let people out when the power fails. Screen size and kit scores stay on the [multi apartment intercom system comparison](/hub/electronic-surveillance/multi-apartment-intercom-system). Listings were scraped on 20 October 2026. This is not a wiring diagram.

You already have a monitor kit, or you are about to order one, and the visitor still cannot open the communal door. Intercom door release lock voltage is the missing half of that purchase.

Our top picks

ANJIELO SMART ANJIELO SMART 7 inch, 3 monitors

Best overall

ANJIELO SMART ANJIELO SMART 7 inch, 3 monitors
5.0/10about £319.99
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LIBO Smart Home LIBO 7 inch, 2 monitors

Rank 2

LIBO Smart Home LIBO 7 inch, 2 monitors
6.4/10about £149.99
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uoweky uoweky 4.3 inch, 3 monitors

Best value

uoweky uoweky 4.3 inch, 3 monitors
5.4/10about £200.99
View offer
On this page
  1. 1.None of these kits includes the strike
  2. 2.12 V or 24 V, and only what the listing names
  3. 3.Fail-safe, fail-secure, and the only way out
  4. 4.Maglock, fire door, and a separate supply

None of these kits includes the strike

None of LIBO B07CQQHTY8, Kadongli B07RJR9HJW, uoweky B07SX3NY45, ANJIELO SMART B0D3HR83HJ or ANJIELO SMART B0FXG9R1ZL lists a strike or a maglock in the box. Kadongli states one-key unlock. LIBO says unlock is supported, and a reviewer asks whether a separate supply is needed because the door does not always open. uoweky states a monitor button and RFID for 500 cards, and still does not list the lock. ANJIELO B0D3HR83HJ names lock types, and its included line is still an indoor screen, installation kits, a memory card, an outdoor doorbell and manuals. Supports unlock means the indoor station is described as able to send a release command. That decision sits on the buying guide.

12 V or 24 V, and only what the listing names

Access-control lock supplies are specified as 12 V or 24 V in the Guild of Architectural Ironmongers’ specifiers’ guide from September 2024. Match the release to the output the listing names. None of these five pages states a milliamp figure. Only ANJIELO SMART B0D3HR83HJ states a lock voltage. It says the doorbell connects to various 12 V electronic locks, and it names electric, electromagnetic, and cathode and anode locks. The lock is not in the box. No kept listing states 24 V. LIBO, Kadongli, uoweky and the six-family title leave the voltage unstated. Do not read the monitor’s 240 V line as the strike supply. That line is the corded monitor. A correct voltage can still be the wrong lock. The next question is what the door does when the power is removed.
ANJIELO SMART ANJIELO SMART 7 inch, 3 monitors

Testsieger

ANJIELO SMART ANJIELO SMART 7 inch, 3 monitors
5.0/10about £319.99
View offer

Fail-safe, fail-secure, and the only way out

CDVI’s UK split is simple. A fail-safe lock is locked only while power is applied, so a power cut unlocks it. A fail-secure lock is unlocked only while power is applied, so a power cut leaves it locked. Electromagnetic locks are fail-safe, because there is no magnetic field without power. Fail-secure is the wrong behaviour on someone’s only way out. NACD’s emergency-egress note, from April 2022, says a fail-secure lock on an escape door needs a mechanical handle or thumb-turn on the inside. A powered-to-lock magnet needs a green break-glass unless that override already exists. Secured by Design’s homes excerpt, for blocks of 25 or fewer flats, expects video, release from the dwelling, and unrestricted egress if power fails, unless a written fire-evacuation policy requires the lock to stay locked. Trades buttons are rejected. That guide is not a certificate for these amazon.co.uk kits.

Maglock, fire door, and a separate supply

A maglock lets go when the power fails. It can still be the wrong purchase when the magnet is the only fastening. BS 7273-4 covers release on a fire alarm. It is not a diagram for these monitors. A LIBO reviewer describes a door that does not always open and asks about a separate supply. Videx’s cable guide, for Videx equipment only, says a lock and a fail-safe release can need more cores. Those counts are not a pinout for LIBO or uoweky. Monitor cable is on the 2-wire versus 4-wire page. Hand the job to an installer when the door is a fire door, when a maglock is the only fastening, or when the release has to follow a fire alarm. The order of work is on the install page.

Common questions

Is the electric lock in the video intercom box?
No. None of LIBO B07CQQHTY8, Kadongli B07RJR9HJW, uoweky B07SX3NY45, ANJIELO SMART B0D3HR83HJ or ANJIELO SMART B0FXG9R1ZL lists a strike or a maglock in the included parts. The pages say one-key unlock, unlock supported, a monitor button, 12 V lock types, or electronic unlocking. Those are descriptions of an output. You buy the release separately.
What voltage should the door release be?
12 V or 24 V, matched to the output the listing names. In this set only ANJIELO B0D3HR83HJ states a lock voltage, and it states 12 V. Nobody states 24 V, and nobody states a milliamp output. Do not read a monitor’s 240 V line as the strike supply. If the page is silent, ask the seller before you order a coil.
What is the difference between fail-safe and fail-secure?
Fail-safe is locked only while power is applied, so a power cut unlocks it. Fail-secure is unlocked only while power is applied, so a power cut leaves it locked. CDVI describes maglocks as fail-safe because the magnet has no field without power. A lock can be the right voltage and still be the wrong one of these two.
Can I put a fail-secure strike on the only way out?
Not unless a mechanical handle or thumb-turn on the inside lets people out when the power is off. NACD expects that override on an escape door. If the inside has no such handle, fail-secure is the wrong lock. Fail-secure does not belong on the only way out.
Does a maglock open when the power fails?
Yes. It is fail-safe, so the door is released when the supply is removed. A maglock can still be the only fastening, and it can still be the wrong product on a fire door.

Related pages

Best multi-apartment intercom

Multi-apartment intercom system

UK 2 wire vs 4 wire video intercom for a small block

UK multi apartment intercom buying guide for flats

How to install a multi apartment intercom in a house

Sources

Public UK sources from the digest first, then the amazon.co.uk listings compared on this page. Prices and stars were taken on 20 October 2026. A search-snippet price from that day is context only.

  1. Videx, wired video intercoms (retrieved 20 October 2026)
  2. GAI, access control specifiers' guide, September 2024 (retrieved 20 October 2026)
  3. Citizens Advice, asking for adjustments (retrieved 20 October 2026)
  4. Equality Act 2010, explanatory notes (retrieved 20 October 2026)
  5. Shelter England, landlord responsibilities for improvements (retrieved 20 October 2026)
  6. Secured by Design, homes guide excerpt (retrieved 20 October 2026)
  7. Approved Document P (retrieved 20 October 2026)
  8. ICO, home CCTV systems (retrieved 20 October 2026)