Controller and Door Operator Replacement in an Occupied 1968 Building
A 1968 six-story office building in Grand Rapids has a 2,500 lb, 350 fpm traction elevator with a relay controller and a motor-generator set. The owner wants to keep the existing car enclosure, 42-in car doors with a 36-in clear opening, and door tracks. The contractor proposes to replace the controller with a solid-state VVVF unit, replace the DC machine with a gearless PM machine, install new ropes, and add a new door operator. The existing car doors have no reopening device, and the door close speed is set at 1.4 ft/s. The contractor argues that because the car enclosure and doors are not being replaced, the reopening device can be omitted and only the controller must meet current code. The building will remain occupied during the work. Michigan has adopted ASME A17.1/CSA B44 with amendments. The inspector asks for the alteration scope and a test plan before issuing the permit.
1. Which items in the proposed scope are alterations under A17.1, and what does that trigger?
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Treat the controller and machine replacement as alterations, not routine maintenance. A17.1 generally defines an alteration as a change to the equipment other than maintenance, repair, or replacement with an equivalent component. New ropes alone might be replacement, but changing the machine, controller, and door operator changes the system and its interfaces.
Once an item is altered, the altered component and its safety interfaces must comply with the code edition adopted by Michigan. The contractor cannot isolate the controller and ignore the door system: a new door operator directly controls the car door, so the door closing force, kinetic energy, reopening device, and reopening timing become part of the altered system. The existing 36-in clear opening may remain as an existing feature if it is not being made worse, but the door operator cannot be installed without meeting current door safety requirements. The permit application should list the alteration scope and the specific code tests.
2. Can the existing car doors remain without a reopening device? What measurements and tests would you require?
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No. Because the door operator is being replaced, the door system is part of the alteration. The car door must have a functioning reopening device, and the installer must measure and document the closing force and kinetic energy at the door edge against the limits in the adopted A17.1/B44 edition. A typical check includes placing a force gauge at the leading edge, testing the reopening device with an obstruction, verifying reopening force and time, and confirming that the door does not close on a passenger.
A 1.4 ft/s closing speed is not automatically acceptable or unacceptable by itself; the force and kinetic-energy measurements decide compliance. If the measurements exceed the code limits, adjust the operator, door closer, or reopening device. Record the results on the test form and have the inspector witness the obstruction test. Do not rely on the argument that the car enclosure is existing; the alteration is the door operator.
3. What inspection and test category should follow this work before the elevator returns to service?
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The alteration requires an acceptance inspection and test before return to service, not just a visual check. The exact category depends on the adopted code and the authority, but expect at least a Category 1 inspection/test plus component-specific tests for the altered controller, machine, door operator, and safety circuits. Because the machine and controller are replaced, test the governor, car and counterweight safeties, buffers, brake, terminal stopping, leveling, emergency operation, and door interlocks.
A Category 5 full-load test is not automatically triggered merely by a controller replacement; it is triggered when the alteration changes rated load, rated speed, or other conditions that require re-verification, or when the authority requires it. If the new machine changes speed or load capacity, perform the full-load and speed tests. Submit the test plan with the permit application and do not place the car in service until the inspector accepts the results.