You've hit on a key challenge and a point of discussion regarding Arc Energy Reduction (AER) in unmetered service equipment. Let's break it down

The Core Issue: Powering AER Devices on Unmetered Services

The fundamental problem is, as you pointed out, powering the AER device itself. All the methods you listed require a source of power. If you tap that power before the metering point, it raises significant concerns: Energy Theft (or Perception of It)

Tapping power upstream of the meter is generally considered theft, as you're using electricity without paying for it. Utilities are very strict about this. Even if the power draw is minimal, the principle is the issue.

Tampering Concerns

Accessing unmetered portions of the service can raise suspicions of tampering with the metering equipment.

Code Violations

While the NEC doesn't explicitly prohibit powering AER from the load side of an unmetered service, it opens the door to violating metering requirements set by the local utility (which has precedence over the NEC in this case) and creating an unsafe situation.

Liability

If something goes wrong (e.g., a fire or shock) because of the unauthorized connection, you, the installer, and potentially the building owner could face significant liability.

Analyzing the Bolswitch Product (and Similar Devices)

The Bolswitch product you linked presents a clever solution, but it still needs careful consideration for unmetered services. Here's why: Voltage Sensing for Activation

Most active arc-flash mitigation systems, like the Bolswitch, use voltage and current sensors to detect an arc flash event. They typically require a low-voltage power supply to operate the sensors and the switching mechanism.

Internal Battery (Possible Solution)

The Bolswitch literature doesn't explicitly state it has a backup battery. This is the key factor to consider. If it has a reliable battery, that could run the device long enough to initiate the current limiting fuses.

Manufacturer's Guidance is Crucial

You MUST contact Bolswitch directly and get written confirmation from them that the product is suitable and approved for use in an unmetered service application. They are the experts on their product, and their official stance is paramount. If they don't authorize it, you cannot use it.

Utility Approval is Mandatory

Before doing anything, contact your local utility. Explain your situation (unmetered service, need for AER, proposed solution). They will likely have specific requirements or prohibitions regarding tapping power before the meter, and their regulations will be the deciding factor.

Permissible Solutions (with Utility and AHJ Approval)

Assuming Utility and AHJ Approval:1.

Dedicated Metered Circuit

The most straightforward (and safest) approach is to have the utility install a separate, metered circuit specifically for powering the AER device. This eliminates any question of energy theft and ensures a properly protected and monitored power source.2.

Backup Battery for Arc Flash Relay

Battery backup is the best option for the arc flash relay if it needs a power source to operate.

Important Considerations



Documentation

Keep meticulous records of all communication with the utility, the Bolswitch manufacturer, and the AHJ. Get all approvals in writing.

Maintenance

Active arc-flash mitigation systems require regular testing and maintenance. Ensure there is a clear plan for this, especially if a battery is involved.*

Grounding

Proper grounding is absolutely critical for the effective operation of any arc-flash mitigation system.

In Summary:

You are correct in identifying the challenge of powering AER devices on unmetered services. Tapping power before the meter is generally prohibited and should be avoided without explicit approval from the utility. Thoroughly investigate battery back up.Contact the manufacturer to get specific approval and then contact your utility and AHJ. Do not proceed without those approvals. Flag for review