Okay, this is a common and understandable issue, especially in situations with diverse existing electrical infrastructure. Let's break down the problem and the compliant solutions.

Understanding the Inspector's Concern

The inspector is likely concerned about Section 200.7(C)(1) of the National Electrical Code (NEC). This section deals with the identification of grounded (neutral) conductors. Here's the gist of it: General Rule

White or gray wiring must be used only for the neutral conductor.

Exception

The NEC allows a white wire to be used as a phase conductor IF it is permanently re-identified to indicate its use as an ungrounded conductor. This re-identification must be done by painting or other effective means at the termination points (i.e., both ends). The color must be something other than white, gray, or green.

Why the Inspector is Concerned with Your Situation

Even though your power supply can accept 120-277V, and the sign functions correctly with 240V using a black and white wire, the potential for future confusion and safety hazards exists. Someone unfamiliar with the sign's wiring (e.g., a future electrician) might assume the white wire is a neutral and take actions based on that (e.g., bonding the white wire to ground), creating a dangerous situation.

Complying with Code (and Keeping It Simple!)

Here are several options for ensuring code compliance while accommodating the wide voltage range and minimizing complexity for your manufacturing process:1. Re-Identification of the White Wire (Most Common and Recommended) Procedure

Use black electrical tape, red electrical tape, or a permanent marker (or paint) to completely and permanently re-identify the white wire with black or red color at both the bell box connection point and at the power supply connection point. Make sure the markings are visible and durable.

Why this works

This satisfies the NEC exception allowing the white wire to be used as a phase conductor, as long as it is clearly and permanently identified as such.

This option is a very common practice, and an easy fix!2. Use Only Black or Red Wires Internally



Procedure

Wire the sign using only black and red wires from the bell box to the power supply. This will eliminate any possibility of someone assuming there is a neutral.

Considerations

You'll need to ensure your inventory includes sufficient black and red wire, and your installers are trained to use them. This removes the potential confusion entirely. Use a green wire for ground.3.

Consider a Terminal Block in the Bell Box



Procedure

Install a small terminal block within the bell box. Run black, red, and green wires to the terminal block.

Advantages

Provides a clean and organized connection point. Makes it easier for electricians to connect to the sign. Potentially reduces strain on the power supply leads.

Documentation and Labeling is Key! Updated Wiring Diagram

Update your sign's internal wiring diagram to clearly show the black and white wire (if you're using the re-identification method) and how it is connected in 240-277V applications.

Additional Label

Consider adding a small, permanent label near the bell box that states: "WARNING: This sign operates on 120-277V AC. White wire may be a HOT conductor. See wiring diagram." "CAUTION: Disconnect power before servicing. Internal wiring may include a re-identified white conductor as a phase wire."

Install Manual

Your installation manual should explain the voltage range, wiring configurations, and the re-identification procedure if applicable.

Talking to the Inspector

The best approach is to be proactive:1. Contact the Inspector

Explain that you understand the concern about the white wire.2.

Present Your Solution

Describe the re-identification method (or the use of only black/red wires) and the additional labeling you plan to use.3.

Reference the NEC

Be prepared to reference NEC Section 200.7(C)(1) regarding the re-identification of conductors.
4.

Show Your UL Listing

Emphasize that your sign is UL-listed and designed for 120-277V operation.

Important Notes



Grounding

Ensure your sign is properly grounded (using the green wire) regardless of the voltage configuration. This is crucial for safety.

UL Listing

Make sure any changes you make to the internal wiring do not invalidate the UL listing of the sign. If you're unsure, contact UL to discuss your proposed modifications.*

Consistency: Apply the chosen wiring method consistently across all signs you manufacture to avoid confusion and potential errors during installation.By implementing one of these strategies, you can ensure that your signs are wired safely and in compliance with the NEC, regardless of the voltage supplied by the customer. Good luck! Flag for review