--- title: Installing Mercury Hardware description: Mercury Panel Installation, Setup And Configuration Guide, mercury,installation,wiring,rs-485,osdp,wiegand,fail safe, fail secure, eol --- [Skip to content](https://help.alocity.com/knowledge/mercury-panel-installation#main-content) English Show submenu for translations [SUBMIT A TICKET HERE](https://help.alocity.com/knowledge/kb-tickets/new?hsLang=en) [![Alocity](https://help.alocity.com/hs-fs/hubfs/alocity-logo%20Full.png?width=181&height=48&name=alocity-logo%20Full.png)](https://www.alocity.com/) Open main navigation Close main navigation - English Show submenu for translations - [SUBMIT A TICKET HERE](https://help.alocity.com/knowledge/kb-tickets/new) - [Contact Support Now](mailto:support@alocity.com) [Contact Support Now](mailto:support@alocity.com) Hello. How can we help you? - There are no suggestions because the search field is empty. 1. [Alocity Help Center (Knowledge Base)](https://help.alocity.com/knowledge?hsLang=en) 2. [Mercury Installation, Setup And Configuration Guide](https://help.alocity.com/knowledge/mercury-installation-setup-and-configuration-guide?hsLang=en) 3. [First Steps](https://help.alocity.com/knowledge/mercury-installation-setup-and-configuration-guide?hsLang=en#first-steps) # Installing Mercury Hardware ## How to Mount, Power and Wire Mercury Controllers, Sub-Panels, Readers and Locks This article covers the physical installation of Mercury controllers and sub-panels: mounting, power, network, the RS-485 bus, readers, locks and door inputs. Always follow the installation manual for each board, available on the [Mercury Security support site](https://www.mercury-security.com/support/), for terminal layouts and electrical ratings. Before installing, verify the location meets these requirements: - **Enclosure:** mount boards in a lockable metal enclosure with room for the power supply and battery. - **Environment:** a clean, dry, climate-controlled space such as an IT room or wiring closet. - **Physical security:** keep the enclosure locked and wire its tamper switch to an input. See [Configuring Inputs](https://help.alocity.com/knowledge/mercury-configuring-inputs?hsLang=en). --- ### 1. Mount the Hardware 1. Mount the controller and sub-panels in the enclosure on standoffs. 2. Leave room for wiring and airflow between boards. 3. Earth-ground the enclosure. *![Screenshot 2026-11-05 103049](https://help.alocity.com/hs-fs/hubfs/Screenshot%202026-11-05%20103049.png?width=421&height=574&name=Screenshot%202026-11-05%20103049.png)* --- ### 2. Connect Power - Power each board with 12–24 VDC from a regulated, battery-backed access control supply. - Use a separate supply, or separate fused outputs, for locks so lock current can't brown out the boards. - Edge models (LP1501, MP1501, MR62e) can be powered by PoE/PoE+ instead. - Check the voltage with a multimeter before connecting the boards. --- ### 3. Connect the Network Connect the controller's Ethernet port to a switch with internet access, using Cat5e or better. See [Mercury Intelligent Controller Network Requirements](https://help.alocity.com/knowledge/alocity-aivr-network-requirements-0?hsLang=en). --- ### 4. Wire the RS-485 Sub-Panel Bus - **Cable:** 24 AWG shielded twisted pair, up to 4,000 ft (1,219 m) in total. - **Polarity:** wire TR+ to TR+ and TR- to TR-. Reversed polarity prevents communication. - **Topology:** daisy-chain the boards, in one board and out to the next. Star and T-tap wiring aren't supported on RS-485. - **Signal ground:** connect GND between boards. - **Shield:** tie the drain wire to earth ground at **one end only**, usually at the controller. Grounding both ends causes ground loops and offline boards. - **Termination:** enable the 120 Ω termination jumper next to the RS-485 port on the controller and on the last sub-panel on the bus only. Leave it off on every board in between. *![Screenshot 2026-11-05 104336](https://help.alocity.com/hs-fs/hubfs/Screenshot%202026-11-05%20104336.png?width=670&height=322&name=Screenshot%202026-11-05%20104336.png)* #### Set each sub-panel's address Each sub-panel needs a unique address on its bus, set with its DIP switches. On the MR52, switches 1–5 set the address (0–31) and switches 6–7 set the speed; Alocity's standard is **38,400 bps**. Boards read their DIP switches only at power-up, so power-cycle after any change. See [Adding Sub-Panels](https://help.alocity.com/knowledge/mercury-adding-sub-panels?hsLang=en). --- ### 5. Wire the Readers - **OSDP readers:** 4 wires (power, ground, data A/B) to the reader port. Several OSDP readers can share a port on S4 boards, each with its own address. Use OSDP Secure where the reader supports it. - **Wiegand readers:** power, ground, D0, D1, and LED/beeper lines as needed. Wiegand runs are much shorter than OSDP; check the reader's maximum cable length. - Note each reader's port and, for OSDP, its address. You'll need them in [Configuring Readers](https://help.alocity.com/knowledge/mercury-configuring-readers?hsLang=en). --- ### 6. Wire the Locks - **Fail-secure locks** (locked without power, such as most electric strikes): wire through the relay's **Normally Open (NO)** contact. - **Fail-safe locks** (unlocked without power, such as magnetic locks): wire through the relay's **Normally Closed (NC)** contact. - Switch lock power through the relay. Don't power locks from the board. - Install a suppression diode across DC locks (or an MOV across AC locks) to protect the relay contacts. - Check that each lock's current is within the relay's contact rating. - Magnetic locks must also release on fire alarm and allow free egress, as required by local code. > **IMPORTANT:** Fail-safe or fail-secure is a life-safety decision. Confirm it with the authority having jurisdiction before wiring. --- ### 7. Wire Door Contacts, REX and Tamper Inputs - **Door contact (DPS):** to an input, usually normally closed. - **Request to exit (REX):** to an input. Motion REX devices often have a second contact to unlock maglocks directly. - **Supervision:** install end-of-line resistors at the device for supervised inputs. Mercury commonly uses 1k/1k. Match the setting in [Configuring Inputs](https://help.alocity.com/knowledge/mercury-configuring-inputs?hsLang=en). - **Tamper:** wire the enclosure tamper switch to the board's tamper input. --- ### 8. Power Up and Check 1. Apply power and watch the controller's LEDs. LED 1 flashing mostly on means the controller is online with the host; mostly off means offline. 2. On each sub-panel, a fast-blinking comm LED means it's talking on the RS-485 bus. A slow blink means check the address, speed and wiring. 3. If the controller is locked or has unknown settings, see [Factory Defaulting a Mercury Controller](https://help.alocity.com/knowledge/mercury-factory-default?hsLang=en). Otherwise, continue to [Adding a Mercury Controller to Alocity](https://help.alocity.com/knowledge/adding-a-device-2-0?hsLang=en). For questions or assistance, please contact your account manager or email [support@alocity.com](mailto:support@alocity.com). - [Quick Start Guides](https://help.alocity.com/knowledge/quick-start-guides?hsLang=en) - [Alocity Control Center Guide](https://help.alocity.com/knowledge/alocity-control-center-guide?hsLang=en#main-content) - [Software and Account General Setup](https://help.alocity.com/knowledge/alocity-control-center-guide?hsLang=en#software-and-account-general-setup) - [Video Security Management](https://help.alocity.com/knowledge/alocity-control-center-guide?hsLang=en#video-security-management) - [User and Group Management](https://help.alocity.com/knowledge/alocity-control-center-guide?hsLang=en#user-and-group-management) - [Access Control Management](https://help.alocity.com/knowledge/alocity-control-center-guide?hsLang=en#access-control-management) - [Intercom Management](https://help.alocity.com/knowledge/alocity-control-center-guide?hsLang=en#intercom-management) - [Aimee](https://help.alocity.com/knowledge/alocity-control-center-guide?hsLang=en#aimee) - [Alocity 1id Mobile App Guide](https://help.alocity.com/knowledge/alocity-1id-mobile-app-guide?hsLang=en#main-content) - [Resident & tenant guide](https://help.alocity.com/knowledge/alocity-1id-mobile-app-guide?hsLang=en#resident-tenant-guide) - [Mobile Credential Users and Super Admins Guide](https://help.alocity.com/knowledge/alocity-1id-mobile-app-guide?hsLang=en#mobile-credential-users-and-super-admins-guide) - [AiVR Installation, Setup And Configuration Guide](https://help.alocity.com/knowledge/aivr-installation-setup-and-configuration-guide?hsLang=en#main-content) - [First Steps](https://help.alocity.com/knowledge/aivr-installation-setup-and-configuration-guide?hsLang=en#first-steps) - [Setup and configuration](https://help.alocity.com/knowledge/aivr-installation-setup-and-configuration-guide?hsLang=en#setup-and-configuration) - [Configuration Tips](https://help.alocity.com/knowledge/aivr-installation-setup-and-configuration-guide?hsLang=en#configuration-tips) - [AI Video Agents](https://help.alocity.com/knowledge/aivr-installation-setup-and-configuration-guide?hsLang=en#ai-video-agents) - [F3D100 Installation, Setup And Configuration Guide](https://help.alocity.com/knowledge/f3d100-installation-setup-and-configuration-guide?hsLang=en#main-content) - [First Steps](https://help.alocity.com/knowledge/f3d100-installation-setup-and-configuration-guide?hsLang=en#first-steps) - [F3D100 Installation and Wiring](https://help.alocity.com/knowledge/f3d100-installation-setup-and-configuration-guide?hsLang=en#f3d100-installation-and-wiring) - [I/O Controller Installation (F3D100)](https://help.alocity.com/knowledge/f3d100-installation-setup-and-configuration-guide?hsLang=en#i-o-controller-installation-f3d100) - [Connecting the F3D100 to 3rd Party readers and controllers](https://help.alocity.com/knowledge/f3d100-installation-setup-and-configuration-guide?hsLang=en#connecting-the-f3d100-to-3rd-party-readers-and-controllers) - [AI-1000 Installation, Setup And Configuration](https://help.alocity.com/knowledge/ai-1000-installation-setup-and-configuration?hsLang=en#main-content) - [First Steps](https://help.alocity.com/knowledge/ai-1000-installation-setup-and-configuration?hsLang=en#first-steps) - [AI-1000 Installation and Wiring](https://help.alocity.com/knowledge/ai-1000-installation-setup-and-configuration?hsLang=en#ai-1000-installation-and-wiring) - [I/O Controller Installation](https://help.alocity.com/knowledge/ai-1000-installation-setup-and-configuration?hsLang=en#i-o-controller-installation) - [Mercury Installation, Setup And Configuration Guide](https://help.alocity.com/knowledge/mercury-installation-setup-and-configuration-guide?hsLang=en#main-content) - [First Steps](https://help.alocity.com/knowledge/mercury-installation-setup-and-configuration-guide?hsLang=en#first-steps) - [Setup and Configuration](https://help.alocity.com/knowledge/mercury-installation-setup-and-configuration-guide?hsLang=en#setup-and-configuration) - [Elevator Control](https://help.alocity.com/knowledge/elevator-control?hsLang=en#main-content) - [First Steps](https://help.alocity.com/knowledge/elevator-control?hsLang=en#first-steps) - [Elevator Control Configuration](https://help.alocity.com/knowledge/elevator-control?hsLang=en#elevator-control-configuration) - [FAQ'S](https://help.alocity.com/knowledge/faqs?hsLang=en#main-content) - [Frequently Asked Questions (FAQ'S)](https://help.alocity.com/knowledge/faqs?hsLang=en#frequently-asked-questions-faqs) - [Common Problems Troubleshooting](https://help.alocity.com/knowledge/faqs?hsLang=en#common-problems-troubleshooting) - [Release Notes And Versions History](https://help.alocity.com/knowledge/release-notes-and-versions-history?hsLang=en) # Alocity alocity.com Help Center Copyright © 2026, Alocity