NEIEP Mechanics Practice Exam

What is the required clearance between the car door and the return jamb?

1. 1/2"

2. 1/4"

3. 3/8"

4. 5/8"

The correct answer is: 1/4"

The required clearance between the car door and the return jamb is typically specified to ensure that there is adequate space for the door to open and close smoothly without any friction or binding that would hinder operation. A clearance of 1/4” strikes a balance between providing enough space to accommodate slight misalignments and the operational growth caused by temperature changes, while still minimizing excessive gaps that could affect the aesthetics and functionality of the installation. When considering the clearance for a car door, it's important for it to comply with standards that promote not only operational efficiency but also safety. This allows for proper air circulation within the vestibule area and minimizes noise during operation—significant factors in lift design and maintenance. Having a larger clearance might create potential problems such as increased wind noise or drafts, which could lead to occupant discomfort or decreased energy efficiency within controlled environments. Conversely, a smaller clearance could result in the door binding against the jamb, leading to operational issues or increased wear over time. Therefore, the 1/4" clearance is both practical and widely accepted in the industry.