Elevator Brake Code Compliance: UCM and Ascending Car Overspeed
New York City DOB guidance for affected single-plunger traction elevators references Unintended Car Movement Protection under ASME A17.1-2013 Section 2.19.2. ASME A17.3-2020 separately addresses Ascending Car Overspeed Protection and Unintended Car Movement. Confirm the adopted code, amendments, device acceptance, and project deadline with the Authority Having Jurisdiction before specifying work.
Who This Affects
New York City's requirement affects legacy geared traction machines with a single-plunger brake design. ASME A17.3-2020 adoption and local amendments vary by jurisdiction. Nevada, Oklahoma, Georgia, Seattle, Phoenix, North Carolina, Ohio, Oregon, Alabama, and Dallas are among the jurisdictions with A17.3-2020 adoption activity. Confirm the current local rule and enforcement date with the AHJ for every project.
- Building owners with affected single-plunger traction machines in New York City
- Traction elevator owners in jurisdictions that have adopted or amended ASME A17.3-2020
- Elevator consultants specifying modernization projects in these jurisdictions
- Property managers planning work that requires a permit, inspection, or acceptance test
Two Approaches to Evaluate
For affected NYC machines, the project team should confirm the accepted approach with DOB and the AHJ. Both machine-brake and independent rail-mounted approaches have different installation scopes, documentation needs, and acceptance requirements.
Dual-Plunger Retrofit Kit
Modify or replace the existing machine brake with a second plunger, adding mechanical redundancy at the brake assembly. This is a code-accepted approach when it is appropriate for the machine configuration and project scope.
- Requires work on the elevator machine itself
- May require OEM coordination or machine-specific parts
- Machine room access and downtime are part of the retrofit scope
- Scope varies by machine make and model
- Confirm the required documentation and acceptance test with DOB or the AHJ
Rail-Gripping Safety Brake (HydraSafe)
A rail-mounted device engages directly on the guide rail outside the machine brake assembly. Confirm the applicable function, code edition, rated-load and rated-speed test scope, and AHJ acceptance for the specific installation.
- No machine modification, removal, or OEM coordination
- Physical rail mounting is typically completed within six hours inside a permitted project
- Project return-to-service timing depends on permitting, testing, and acceptance
- Technical certificates and supporting documentation are available for project review
For projects where machine-room access is limited or installation scope needs to be minimized, a rail-mounted approach may offer practical advantages. The project team should confirm code applicability and acceptance with the AHJ.
How HydraSafe Works
HydraSafe Brake engages directly on the guide rail when its detection and actuation system is triggered. Unintended Car Movement and Ascending Car Overspeed are separate code functions under ASME A17.3-2020, with distinct provisions and test criteria. Request the current technical documentation for the device configuration, rated load, rated speed, and applicable certification scope before specification.
See the full How It Works explanationCommon Questions from Specifiers
Plan Your Compliance Project
Our team can provide technical documentation and help your project team prepare for jurisdiction-specific review. Confirm final requirements with the local AHJ.