Otis holds a clear lead for searchable elevator service documentation. KONE Spares offers specific manuals for older traction, hydraulic, and control systems.
For older elevators, the best source is usually the original manufacturer’s documentation, but the most useful source depends on how old/obsolete the equipment is.
Best sources, in order
Manufacturer/OEM technical documentation — best choice
For Otis, the OtisWave portal has catalogs covering older equipment, including Westinghouse and Thyssen systems.
TK Elevator (TKE) specifically offers wiring diagrams and layouts for TKE, Dover, and Swift equipment, including archived technical bulletins.
Other OEMs such as Schindler maintain documentation libraries, although these tend to emphasize newer/discontinued equipment rather than very old controllers.
National Association of Elevator Contractors (NAEC) is an excellent source for technical references and training material. Its CET curriculum specifically covers schematic circuit diagrams, wiring diagrams/prints, electrical troubleshooting, and elevator control systems.
National Elevator Industry Educational Program (NEIEP) is another authoritative technical resource, particularly for understanding older control technologies and interpreting prints.
Old elevator manuals/books and industry archives
For equipment from the 1940s–1980s, old service manuals, controller manuals, adjustment instructions, and manufacturer's parts catalogs can be much more valuable than modern documentation.
Search using the manufacturer + controller/model designation + “wiring diagram,” “print,” “adjustment manual,” “service manual,” or “schematic.”
Don't search only by elevator model—the controller manufacturer and controller designation are often the key identifiers.
One particularly useful tip
If you're trying to identify documentation for a specific old elevator, get the information from the controller nameplate and existing prints first. Useful identifiers include:
Manufacturer: Otis, Westinghouse, Dover, Haughton, Montgomery, Armor, etc.
Controller/model number
Serial number
Installation year
Relay/selector/controller type
Motor-generator or solid-state control type
Existing drawing/print numbers
If you give me the manufacturer, approximate year, and controller/model number (or a photo of the controller/nameplate), I can search specifically for the service manual and wiring diagrams for that elevator.
The best sources and strategies for tracking down these hard-to-find diagrams include:
Original Equipment Manufacturers (OEMs)
Contacting Otis, Schindler, ThyssenKrupp, or KONE: If the legacy brand was absorbed by one of the major modern conglomerates, their local branch or technical support desk sometimes holds archival data. However, they usually require proof of building ownership or an active service contract to release proprietary prints.
Elevator Community Forums: Private or professional trade boards (like local mechanic networks and specialized forums) are often the ultimate underground resource. Technicians frequently trade scanned PDF copies of hand-drawn or blueprinted relay-logic schematics for obsolete Dover, Montgomery, or Armor elevators that no longer exist in official corporate databases.
Local Municipal or State Elevator Inspection Archives
In many jurisdictions, original acceptance tests, wiring diagrams, and permits were required to be filed with the local Department of Buildings (DOB) or state elevator safety division when the unit was installed or modernized. Submitting a public records or archival request to the local municipality can occasionally turn up the blueprint left behind in old inspection files.
If you can share the specific manufacturer and model or controller type (e.g., Otis, Dover, Armor, relay-logic vs. early microprocessors), I can help you pinpoint whether there is a direct distributor or specific archival route for that brand.
