Okay, let's break down the situation and figure out the best course of action. It sounds like you're having some second thoughts about the aircraft cable suspension you specified for the cafeteria pendant lights, especially considering the presence of large ceiling fans.Here's a structured thought process to help you decide

1. The Risk of Swaying:
Yes, there's a high likelihood of swaying. Large ceiling fans create significant air movement. Even with a 4-5 foot separation, the turbulence they generate will almost certainly cause aircraft cable-suspended pendants to sway, especially larger or heavier pendants. The longer the cable, the more pronounced the sway will be. This isn't just an aesthetic issue; it can be distracting, potentially damage the lights over time due to collisions, and even create a strobe-like effect if the lights are swaying across the path of the fan blades.2. Why Stem Mounts are Usually Better in this Situation



Stability

Stem mounts offer significantly more stability than aircraft cables, particularly in areas with air movement. They resist swaying because they are rigidly connected to the ceiling.

Safety

Minimize risk of lights colliding with each other or fan blades.

Aesthetics

They maintain a more consistent and professional appearance. Swaying lights can look sloppy and unfinished.

3. Key Considerations for Your Decision



Pendant Weight

How heavy are the pendants? Heavier pendants on aircraft cable are more susceptible to swaying.

Cable Length

The longer the aircraft cable, the greater the sway. You can technically shorten the aircraft cable to try and mitigate the sway.

Fan Speed

Higher fan speeds, more intense turbulence.

Construction Team

It will be difficult to shorten on the field, because you will need to cut cables and crimp with special tools, so most likely the construction team will not attempt to modify on the field.

Light Fixture Cost

How expensive are the pendants? If they're relatively inexpensive, the cost of replacing them might not be prohibitive.

Manufacturer Options

Does the manufacturer offer a stem mount option for the pendants you specified? This is the most critical question. If they don't, you're looking at potentially specifying entirely different fixtures.

Change Order Cost

Get a quote from the contractor ASAP. Include the cost of the new stem mounts, the labor to install them (which could be more straightforward than aircraft cable, depending on the situation), and any potential adjustments to the electrical wiring.

Your Liability

As the designer, you have a responsibility to specify lighting that is safe, functional, and aesthetically appropriate. If you know there's a high likelihood of problems with the aircraft cables, proceeding with the original spec is risky.

Client Satisfaction

Consider the client's perspective. Swaying lights in a cafeteria are likely to be a source of complaints and frustration.

4. Recommended Actions


Immediately Contact the Manufacturer

Confirm if a stem mount option is available for the specified pendants. Get detailed information on the stem length options and installation requirements.2.

Contact the Contractor for a Change Order Quote

Provide the manufacturer's stem mount information and request a formal quote for the change order. Be clear about what the change order covers (materials, labor, disposal of the aircraft cable hardware, etc.).3.

Assess the Cost vs. Risk

Carefully compare the cost of the change order to the potential problems caused by swaying lights. Factor in the cost of future maintenance/repairs, client dissatisfaction, and your professional reputation.4.

Document Everything

Keep a detailed record of all communication with the manufacturer, contractor, and client. This documentation is crucial for managing potential disputes.5.

Discuss with Client (if applicable)

If you have a direct relationship with the client, explain the situation and your recommendation for stem mounts. Frame it as a preventative measure to ensure a more functional and aesthetically pleasing space.

5. Potential Alternatives (If Stem Mounts are Not Available)

If a stem mount isn't an option, you have a few (less desirable) choices:

Damper Mechanisms

Some manufacturers offer small damper mechanisms to attach between light and cable. This might help reduce minor sway, but is unlikely to solve the turbulence issue.

Different Lights Entirely

If a stem mount isn't possible, then you may need to look at a different pendant fixture (or even a different type of fixture altogether, like recessed lighting or surface-mounted fixtures).

Lower Fan Speeds

This is not ideal, but might be acceptable to the client.

6. Conclusion

In my professional opinion, based on your description,

you should strongly consider initiating a change order to switch to stem mounts if the manufacturer offers them. The risk of swaying lights in a cafeteria environment with ceiling fans is significant. A change order is a proactive solution that will likely save you headaches (and potentially costs) in the long run. Flag for review