Access control is one of those systems people rarely think about until something goes wrong. A power outage is exactly that kind of moment, and if your building’s access control setup isn’t prepared for it, you could find yourself locked out, or worse, with doors that fail wide open. Here’s what actually happens during a power loss and how a well-designed system handles it.
The Two Ways a Door Can Fail
Every access-controlled door is wired to behave in one of two ways when power is cut: fail-safe or fail-secure. This isn’t a preference setting you toggle after installation; it’s a fundamental design decision that should be made based on the door’s purpose and your building’s safety requirements.
A fail-safe door unlocks when power is lost. This is common on egress doors in schools, hospitals, and commercial buildings where occupant safety is the top priority. If something goes wrong, people need to get out, and a locked door is a liability. Many Denver and Lakewood commercial properties we work with choose fail-safe on their main exits for exactly this reason.
A fail-secure door stays locked when power is cut. This is appropriate for server rooms, financial vaults, evidence storage, or any space where unauthorized access during an outage would be a serious problem. Data centers and financial institutions in the Englewood, Littleton, and Arvada areas often require fail-secure on their most sensitive spaces.
Knowing which mode each door operates in, and whether that matches the original intent, is something we review carefully on every installation and assessment we do.
Where Backup Power Comes In
Most modern access control systems include some form of backup power, but not all backup solutions are equal. The most common options are:
- Uninterruptible power supplies (UPS): Battery-backed units that kick in immediately when the main power drops. A quality UPS can keep a system running for several hours depending on load.
- Panel-level batteries: Many access control panels have onboard battery backup built in, which handles the controller and connected locks even if the UPS for the broader network goes down.
- Generator integration: Larger facilities often tie access control into a backup generator. This works well but introduces a short gap between outage and generator startup, which is why UPS and generator solutions are often paired together.
For a small office, a single UPS might be plenty. For a multi-building campus or a government facility, layered redundancy is worth the investment.
What Happens to the Network Side
Cloud-managed and IP-based access control systems add another layer to consider. If your access control communicates over your network, and the network switches or wireless access points lose power, that communication link breaks, even if the door hardware itself has battery backup.
This is why we pay close attention to the full infrastructure picture, not just the locks. Network switches along critical paths should be on UPS protection too. For clients running Verkada solutions, which we install and support as an authorized provider, the local devices are designed to continue operating in offline mode, caching credentials and activity until connectivity is restored. That’s a meaningful advantage in an outage scenario.
Common Gaps We See in Existing Systems
After nearly 30 years working in low-voltage technology across the Front Range, including commercial properties in Denver, Lakewood, Arvada, Littleton, Englewood, and surrounding areas, we’ve audited a lot of systems that had thoughtful intentions but gaps in execution. The most common issues we find include aging or undersized UPS batteries that haven’t been tested in years, doors configured in fail modes that don’t match the space’s actual use, and network infrastructure left off the backup power plan entirely.
None of these are catastrophic on their own, but in a power outage they become real problems quickly. A periodic review of your access control system, including the backup power components, is a straightforward way to catch these issues before a storm or grid event does it for you.
Planning for the Unexpected
October in Colorado can bring early snowstorms, high winds, and utility disruptions, and that’s a good reminder that power outages aren’t hypothetical. Whether your facility is in Denver proper or further out in the mountain communities, having a documented plan for how your access control behaves during an outage gives your team a lot more confidence in how to respond.
If you’re not sure how your current system is configured, or you’re planning a new installation and want to get the power backup strategy right from the start, we’re glad to help. Give us a call or drop us an email and we can talk through your situation.
