# Wire a Door to an AC41 Cassette

The Verkada [AC41 access controller](https://docs.verkada.com/docs/door-controller-ac41-datasheet.pdf) comes with 5 removable cassettes, designed to make the installation and cabling process quick and easy.

{% hint style="warning" %}
See [Wire A Door to a Verkada Access Controller](https://help.verkada.com/access-control/installation/wire-a-door-to-a-verkada-access-controller) if you have an [AC42](https://docs.verkada.com/docs/access-control-ac42-quick-start-guide.pdf) or [AC62](https://docs.verkada.com/docs/verkada-ac62-door-controller-install-guide.pdf).
{% endhint %}

***

### Before you begin

{% hint style="danger" %}
⚠️ Ensure power is disconnected from the AC41 and locking hardware before you wire readers and other devices. Failure to do so can damage the AC41.

Before you begin to wire, we recommend that you configure the locking hardware.
{% endhint %}

Before you begin the wiring process, we recommend that you review the locking hardware guidelines.

At a high level, review how to wire a door to an AC41 cassette:

{% stepper %}
{% step %}
[**Remove the cassette**](#remove-the-cassette)**.**
{% endstep %}

{% step %}
**Connect the locks (**[**dry**](#h_7496ed9622) **|** [**wet**](#h_b312a8156a)**).**
{% endstep %}

{% step %}
[**Connect the reader**](#h_4ea2173362)**.**
{% endstep %}

{% step %}
[**Connect the inputs**](#h_b323f6ba5f)**.**
{% endstep %}

{% step %}
[**Plug the cassette**](#insert-the-cassette) **back into the AC41.**
{% endstep %}
{% endstepper %}

### Understand locking hardware

#### Fail-secure and fail-safe locks

Be aware of the different ways to configure locking hardware:

* **Fail-secure** locks require electrical power to unlock. In their normal unpowered state, they remain locked. They use a Normally Open (NO) circuit. When power is interrupted, it remains locked.
* **Fail-safe** locks require electrical power to remain locked. In their normal powered state, they remain locked. They use a Normally Closed (NC) circuit. When power is interrupted, it unlocks.

{% hint style="warning" %}
Some door strikes can be wired as fail-safe and some electromagnetic locks can be fail-secure; always check your third-party locking hardware wiring instructions and ensure you’re using the right configuration for your requirements.
{% endhint %}

#### Dry vs wet setup

* **Dry**—The AC41 does not provide power to the locking hardware (typically used with external power supplies).
* **Wet**—The AC41 provides 12V or 24V power to the locking hardware.

{% hint style="info" %}
Always use an external access power controller (dry setup) when wiring an electromagnetic lock (maglock).
{% endhint %}

***

### Step 1: Remove the cassette

From the side tabs, lift the door cassette to remove it from the AC41.

<div align="left" data-with-frame="true"><figure><img src="https://134288481-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaaHs5RfKqv9Z49mi02cC%2Fuploads%2FfLXLVSWyokhV45XaWUiY%2FScreenshot%202026-01-30%20at%2010.15.28%E2%80%AFAM.png?alt=media&#x26;token=7ec98b64-3425-4d37-acc6-d16205593cad" alt=""><figcaption></figcaption></figure></div>

{% hint style="warning" %}
Before you wire your doors, see the [recommended wires for the AC41](https://help.verkada.com/access-control/installation/wire-a-door-to-a-verkada-access-controller/recommended-wires-for-access-controllers).
{% endhint %}

***

### Step 2: Connect the lock (APC—Dry Contact)

When using an access power controller (APC), which uses a dry contact, ensure that **None** is selected on the door power selection switch. The APC then detects if the AC41 relay is open or closed, and translates that to the lock. Maglocks, crash bars, and gates are almost always wired using an APC.

**Fail Secure**

<div align="left" data-with-frame="true"><figure><img src="https://134288481-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaaHs5RfKqv9Z49mi02cC%2Fuploads%2FaVSO77rb9FwMmf7FDrBt%2FScreenshot%202026-01-30%20at%2010.15.40%E2%80%AFAM.png?alt=media&#x26;token=07dfede5-c94b-4416-ba2c-a135accd0a4d" alt=""><figcaption></figcaption></figure></div>

**Fail Safe**

<div align="left" data-with-frame="true"><figure><img src="https://134288481-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaaHs5RfKqv9Z49mi02cC%2Fuploads%2F3WCOKLP70NlCsWNfFHxz%2FScreenshot%202026-01-30%20at%2010.15.50%E2%80%AFAM.png?alt=media&#x26;token=dad879c5-2695-4bd9-b3df-60e7ab154edc" alt=""><figcaption></figcaption></figure></div>

{% hint style="danger" %}
⚠️ When the AC41 door power selection switch is set to **None,** the relay is not completely dry. The AC41 has the ability to power locks at 12V or 24V, but as a result, the relay is not completely dry. Isolation or [common ground](https://help.verkada.com/access-control/troubleshooting/verkada-ac41-status-led/configure-dry-lock-on-an-ac41) issues may occur. **This issue is unique only to the AC41 model.**
{% endhint %}

***

### Step 3: Connect the lock (wet)

In a wet configuration, ensure that power selection for each door is set to the correct voltage, as outlined by the locking hardware specifications:

* Set it to **12VDC** for 12-volt locking hardware.
* Set it to **24VDC** for 24-volt locking hardware.

The AC41 is rated to power 12V locks up to 700mA and 24V locks up to 350mA.

<div align="left" data-with-frame="true"><figure><img src="https://134288481-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaaHs5RfKqv9Z49mi02cC%2Fuploads%2FQ4IXLY7Ac2vM589D3UpE%2Fgif.gif?alt=media&#x26;token=9ffcb30f-5da3-4ebf-8f6d-57668b0ddc5a" alt="" width="563"><figcaption></figcaption></figure></div>

#### Wet 12V / 24V NO-COM

If you have a fail-secure lock, connect to NO-COM where LOCK (+) positive goes into NO (fail secure) and LOCK (–) goes into COM.

#### Wet 12V / 24V NC-COM

If you have a fail-safe lock, connect to NC-COM where LOCK (+) positive goes into NC (fail-safe) and LOCK (–) goes into COM.

{% hint style="info" %}
Always use an external access power controller when wiring a maglock. **Do not use the wet configuration**.
{% endhint %}

{% hint style="danger" %}
⚠️ When connecting the lock in the wet configuration, ensure the negative of the lock goes into the COM port, as shown in the diagrams below. Polarity matters.
{% endhint %}

<div align="left" data-with-frame="true"><figure><img src="https://134288481-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaaHs5RfKqv9Z49mi02cC%2Fuploads%2FtroMj5JZT1FerWuZmi0d%2F4.png?alt=media&#x26;token=0ccf8e03-e2f0-45e8-ac94-eb17cc4d8c62" alt=""><figcaption></figcaption></figure></div>

***

### Step 4: Connect the reader

The AC41 is rated to power readers at 12V up to 250mA via the + (VIN) and – (GND) connection. Verkada readers use the far left 4-port inputs while standard Wiegand readers use the middle 6-port inputs.

<div align="left" data-with-frame="true"><figure><img src="https://134288481-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaaHs5RfKqv9Z49mi02cC%2Fuploads%2FVqp5iPGwWSD0ArdyL6LK%2F20210622_AC41_Artwork-11.jpg?alt=media&#x26;token=4925a613-4a33-433e-8494-449d6103815f" alt=""><figcaption></figcaption></figure></div>

<div align="left" data-with-frame="true"><figure><img src="https://134288481-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaaHs5RfKqv9Z49mi02cC%2Fuploads%2FLDF0S4fYnOlfxxS1tzKK%2F5.png?alt=media&#x26;token=b620b7b1-286a-441c-8d58-be6bc070d1ea" alt=""><figcaption></figcaption></figure></div>

The Verkada AD31 uses the following color scheme:

**+ -** Red

**– -** Black

**A** - Purple

**B** - Blue

<div align="left" data-with-frame="true"><figure><img src="https://134288481-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaaHs5RfKqv9Z49mi02cC%2Fuploads%2FHrUoGoB7AKF9oM5EMGfc%2F6.jpg?alt=media&#x26;token=839e0b3a-fdbd-4d23-93ef-cd2bc6a18c91" alt=""><figcaption></figcaption></figure></div>

The Verkada AD32 and AD33 uses the following color scheme:

**+ -** Red

**– -** Black

**A** - White

**B** - Green

<div data-with-frame="true"><figure><img src="https://134288481-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaaHs5RfKqv9Z49mi02cC%2Fuploads%2F0gZLKmsGqCw9F0q28MVg%2F7.png?alt=media&#x26;token=8f602985-71ec-477b-a4dc-8d98103815fb" alt=""><figcaption></figcaption></figure></div>

Typical Wiegand wiring uses the following color scheme:

**+ -** Red

**– -** Black

**D0** - Green

**D1** - White

<div align="left" data-with-frame="true"><figure><img src="https://134288481-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaaHs5RfKqv9Z49mi02cC%2Fuploads%2FfeNaxKqg1h53zrmhRvOD%2F8.jpg?alt=media&#x26;token=fa77b4ec-591c-4228-856c-547997ed65c2" alt=""><figcaption></figcaption></figure></div>

{% hint style="warning" %}
Each door cassette can be connected to both a Wiegand reader and a Verkada reader. The AC41 supports simultaneous Verkada reader and Wiegand connections.
{% endhint %}

***

### Step 5: Connect the inputs (optional)

Both the [Door Position Indicator (DPI)](#h_a21dc64e91) and the [Request-to-Exit (REX)](#request-to-exit-rex-optional) inputs are dry contacts. Installing these inputs is optional and can be configured in Verkada Command.

#### DPI (Door Contact) (optional)

{% hint style="warning" %}
The Verkada AC41 expects the DPI to be NC.
{% endhint %}

<div align="left" data-with-frame="true"><figure><img src="https://134288481-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaaHs5RfKqv9Z49mi02cC%2Fuploads%2F7qUeB2nfrxfC6Rf2L4Vg%2F9.png?alt=media&#x26;token=f32860a2-2546-49bf-936f-b8902a7e7a5d" alt="" width="375"><figcaption></figcaption></figure></div>

### REX (optional)

You can configure the REX to release the lock in Command (most commonly seen in maglocks) or simply show door forced open (DFO) events. You can also configure the REX unlock time.\
​\
REX motion sensors and REX buttons are often required by regulation to meet building codes for access-controlled entrance doors.

{% hint style="info" %}
The REX motion sensor should be wired into the REX terminals on the AC41 while the emergency REX button should be wired directly in line with the lock to provide direct interruption of power in an emergency situation.
{% endhint %}

{% hint style="warning" %}
Verkada AC41 expects the REX to be NO.
{% endhint %}

<div align="left" data-with-frame="true"><figure><img src="https://134288481-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaaHs5RfKqv9Z49mi02cC%2Fuploads%2Fu6cBwQ3iuIBFMX1DEAGI%2Frex.png?alt=media&#x26;token=cd7ab03d-a643-4349-9c5d-88f1fc65dde2" alt="" width="375"><figcaption></figcaption></figure></div>

#### Powered REX

If necessary, you can utilize the 12V port for the unused reader to power the REX device.

<div align="left" data-with-frame="true"><figure><img src="https://134288481-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaaHs5RfKqv9Z49mi02cC%2Fuploads%2FIgawoC3JqWVapSgC3PK6%2Frex2.png?alt=media&#x26;token=8b037569-09a9-422d-bd5e-6bf07928b6ac" alt=""><figcaption></figcaption></figure></div>

**Wet configuration with emergency REX button release**

<div align="left" data-with-frame="true"><figure><img src="https://134288481-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaaHs5RfKqv9Z49mi02cC%2Fuploads%2F3mRnZFiNZcA3Vy375OZJ%2F10.jpg?alt=media&#x26;token=5e839fb3-0102-4879-a2c6-68efa854182b" alt="" width="563"><figcaption></figcaption></figure></div>

**Dry configuration with emergency REX button release**

<div align="left" data-with-frame="true"><figure><img src="https://134288481-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaaHs5RfKqv9Z49mi02cC%2Fuploads%2FVC0fx3RimVeaEMbHy4Ry%2F12.jpg?alt=media&#x26;token=827b5f78-27a9-4f93-a88e-65e67df3e6f7" alt="" width="563"><figcaption></figcaption></figure></div>

***

### Step 6: Insert the cassette

To finalize the installation, insert the cassette back into the desired slot on the AC41, then power the AC41 back on.

<div align="left" data-with-frame="true"><figure><img src="https://134288481-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FaaHs5RfKqv9Z49mi02cC%2Fuploads%2FrlsO6YoDLKWgUyw4nwH1%2Fcropped.jpg?alt=media&#x26;token=fa9421e3-e8f0-41bd-b597-05c210ef63b6" alt="" width="375"><figcaption></figcaption></figure></div>