Elevator emergency communication is one of the most quietly reliable systems in a commercial building — and one of the most exposed to the copper POTS retirement. Every passenger elevator in California is required to provide two-way communication from the cab to a live person, on a supervised line, per ASME A17.1 §2.27.1.
What the code actually requires
The current ASME A17.1 language requires:
- A two-way voice communication device inside the elevator cab
- Communication to on-site personnel or an emergency service capable of dispatching help 24×7
- Line supervision — the system must detect when the communication path is not functional and notify appropriately
- Visual indication in the cab that the call has been received and that help is on the way
- Video communication in most new-construction elevators, per the 2019 and later editions
The "supervised line" language is where copper POTS traditionally lived. When the copper is cut, the elevator loses its supervised path — and, technically, is no longer compliant.
Your replacement options
Cellular elevator phone service (most common)
Purpose-built cellular elevator phones from Kings III, Rath, and Viking install directly in the cab, use LTE-M or 4G LTE, and connect to a 24×7 monitoring center. They handle line supervision, ambient noise cancellation, hands-free operation, and — where required — video. Monthly cost is typically comparable to the retired POTS line, sometimes lower.
SIP over managed IP
Some buildings with a robust in-house VoIP system route elevator lines over SIP. This is compliant if the SIP trunk is supervised end-to-end, backed by a UPS with the required run time, and monitored 24×7. In practice, dedicated cellular is more common — it decouples the elevator from IT changes.
Managed facility voice network (MFVN)
A carrier-supplied MFVN is functionally similar to POTS from the elevator's perspective, meets the supervision requirement, and is explicitly recognized in current code language. Availability varies by market.
What to avoid
- Consumer VoIP (Vonage, Ooma) is not appropriate. It lacks the supervision, power-loss behavior, and monitoring center required by A17.1.
- Standalone cellular "hotspot" adapters strung together with a residential-grade phone. It may pass a casual inspection and then fail during the actual event.
- Waiting for the copper to be cut before planning a replacement. Once the wire center is retired, your elevators are non-compliant on day one.
How the state inspection interacts
Elevators in California are inspected under the Division of Occupational Safety and Health (Cal/OSHA) Elevator Unit. During annual inspection, expect the inspector to verify that the two-way communication works, reaches a live person, and is supervised. A dead POTS line means a failed inspection and, potentially, a shutdown notice.
Plan the migration once
If you have three elevators in a building, replace all three at the same time. Same install visit, same monitoring account, same billing consolidation. Trying to do them one at a time as budgets allow tends to leave the last cab non-compliant for months.
The copper POTS retirement is the single largest coordinated life-safety migration California commercial buildings have seen in a generation. Elevator phones are the piece most owners forget until the code inspector walks in. Get them on the same project as your fire alarm dialer migration and both problems solve at once.