Okay, this is a common point of confusion and code interpretation, and unfortunately, LADBS is known for being strict about these things. Let's break it down

Why LADBS is Requiring a Disconnect
Local Code Amendments and Interpretations

Los Angeles (and California in general) often has local amendments to the National Electrical Code (NEC) that are stricter. They also have specific interpretations by the AHJ (Authority Having Jurisdiction), which in this case is LADBS.

General Safety and Lockout/Tagout

The core idea behind disconnects is to ensure that maintenance or repair personnel can safely de-energize equipment at the equipment location before working on it. This aligns with OSHA's lockout/tagout procedures. Even if the equipment doesn't have a motor or heater, the argument is that it needs to be safely isolated.

Easier Servicing

A disconnect switch right at the BMS panel can make it easier and faster to work on. This reduces downtime.

Enforcement

It's possible that this is a new enforcement emphasis or a change in the inspector's interpretation.

NEC (National Electrical Code) Considerations



Article 408.54 Switchboard and Panelboard Overcurrent Protection Although not specifically talking about a disco, this section may be the rational for an overcurrent device, such as a breaker. Article 645 Information Technology Equipment Is a very specific article. If your IDF room qualifies as an "Information Technology Equipment" room, then NEC 645.10 specifies a disconnecting means is needed for HVAC systems and remote power control. It would also require fire detectors and other specific elements. Emergency Systems

If any of your systems in the IDF room are part of an emergency system (fire alarm, emergency lighting, etc.), there might be specific disconnect requirements related to those systems.

Will You Need a Disconnect for Every Panel?

This is the key question, and the answer depends on a few factors:1. What Did the Inspector Say? The most important thing is to clarify with the LADBS inspector. Ask them specifically what code section they are citing that requires the disconnect. This will guide your next steps.2. Similar Panels and Systems

The inspector may want similar panels in that room also to have a disconnect. The argument may be that each piece of equipment has 120V or 277v going into it, and the inspector wants it off to work safely.3.

Panel Location and Accessibility

If the panel is difficult to reach, or if the breaker panel is not easily accessible (e.g., locked room, far away), that might increase the likelihood of needing a local disconnect.4.

Voltage

If any of your equipment runs on high voltage, it's more likely to need a disconnect.

Practical Steps to Take


Talk to the Inspector

Before doing anything else, contact the inspector. Be polite and ask for clarification on the specific code section that requires the disconnect. Also, ask if this requirement will apply to all similar panels in the IDF room. If you can get something in writing from the inspector, that's even better.2.

Review the Plans

Look back at your approved electrical plans for the IDF room. If disconnects were not shown on the plans, but now the inspector is requiring them, that could be a point of discussion (though it doesn't guarantee they'll back down).3.

Consult with a Licensed Electrical Engineer or Contractor

A qualified electrical professional familiar with LADBS requirements can assess the situation, review the code, and advise you on the best and most cost-effective solution. They can also help you negotiate with the inspector if necessary. They may have seen this issue before and know the preferred solutions.4.

Consider the Solution

The "bell box" solution you mentioned is probably the most cost effective as long as its accessible. I have run into this a few times and that is the route most contractors take.5.

Documentation

Keep detailed records of all communication with LADBS, including dates, names, and what was discussed. This is important if you need to appeal or challenge a decision.

Important Considerations



Cost

Adding disconnects can add to the cost of the project, especially if you have to do it for multiple panels.

Space

Make sure you have enough space to install the disconnects properly.

Accessibility

The disconnect switch must be readily accessible.

In summary: While you are right that disconnects are typically associated with equipment that poses a significant electrical hazard, it's not uncommon for AHJs, especially in strict jurisdictions like Los Angeles, to require them for a wider range of equipment for safety and maintenance purposes. Talk to the inspector, consult with an expert, and document everything. Flag for review