You've outlined the core problem and some potential solutions accurately. The critical issue is ensuring that disconnecting the utility power doesn't inadvertently energize the house via the generator. Let's break down your proposed solutions and address the NEC compliance aspects.

Understanding the Problem

Your understanding is correct. The NEC 230.85 requirement is designed to provide a single point of disconnect for emergency responders. The presence of an automatic standby generator significantly complicates this, as a simple disconnect could trigger the generator and re-energize the system.

Analysis of Proposed Solutions1. Two Disconnects

This is generally discouraged and likely

not compliant with the intent of NEC 230.85. The goal is a single, easily identifiable disconnect. Requiring emergency responders to locate and operate two separate switches increases the risk of error, delay, and potential hazard. It introduces confusion and undermines the purpose of the emergency disconnect.
2. Disconnect Between Panel and ATS

This approach is

not a viable solution. It isolates the house panel from both utility and generator, but leaves the ATS and generator energized. This doesn't eliminate the hazard because the generator could still be manually started or malfunction, potentially backfeeding the system. It also does not meet the requirement of disconnecting ALL power sources to the building.3. Using EDS to Interrupt Remote Start

This is the most promising approach, but needs careful examination for NEC compliance. Here's a detailed breakdown:

Concept

You are proposing to use the EDS to break the control circuit that initiates the automatic generator start. By doing so, even if the utility power is lost (simulated by opening the EDS), the generator won't start. This is a good way to eliminate the hazard.

NEC Concerns



230.85 (Emergency Disconnects)

While not explicitly prohibiting this approach, the focus of this section is on disconnecting conductors that carry power to the building. Your concern about interrupting the control wiring is reasonable, as is the approach you propose. The spirit of the code is to eliminate all sources of power, and disabling the automatic start achieves that.

300.3 (Conductors of Different Systems)

A key area of concern is running low-voltage control wires (the generator remote start wires) within the same raceway, cable, or enclosure as the 120/240V service conductors. This can be permissible, but only under strict conditions:

300.3(C)(1)

Wiring Methods. If the control wiring and power conductors are installed in a raceway, that raceway must be approved for the voltage of the highest voltage circuit within the raceway, in this case 240 volts. This means using the correct type of conduit and fittings. If the control wiring and power conductors are installed in a cable, that cable must be approved for the voltage of the highest voltage circuit within the cable, in this case 240 volts.

300.3(C)(2)

Equipment Wiring. Wiring internal to factory assembled equipment is not governed by the same constraints as field installed wiring. This exception would not be applicable in your scenario.

Article 700 (Emergency Systems)

If your generator is part of a legally required emergency system (e.g., for fire pumps or life safety systems), additional requirements apply. It's unlikely in a typical residential setting.

Generac Installation Manual

You MUST consult the Generac installation manual for their specific recommendations and requirements for remote start connections. They may have specific instructions or warnings about using external disconnects on the control circuit.

Implementation



Use the correct blade of the EDS

You would need a 3-pole EDS. Two poles would be for the normal L1 and L2. The third pole should be dedicated solely to switching the generator remote start control circuit. The neutral (N) wire would NOT be routed through the EDS.

Wiring Method

The remote start control wires MUST be rated for the same voltage as the L1 and L2 cables (240 volts).

Enclosure

The generator remote start control wires could be routed through a separate conduit/fitting through the EDS enclosure.

Signage

A clear label should be placed next to the EDS stating: "EMERGENCY DISCONNECT - DISCONNECTING THIS SWITCH WILL PREVENT AUTOMATIC GENERATOR START."

Recommendations and Considerations1. Consult with a Licensed Electrical Engineer or Master Electrician

This is not a DIY project. The NEC is complex, and the potential for serious injury or death is real. A qualified professional can assess the situation, ensure code compliance, and provide a safe and reliable installation. They can also review local amendments to the NEC that might affect your installation.2.

Contact Your Local Authority Having Jurisdiction (AHJ)

The AHJ (usually the city or county electrical inspector) has the final say on code interpretation and enforcement. It's prudent to discuss your proposed solution with them before starting any work. They may have specific requirements or preferences.3.

Consider Alternative Solutions (if possible)



Generator Control Module with Emergency Stop Input

Some generator control modules have a dedicated emergency stop input that can be wired to the EDS. When this input is activated, the generator will shut down and prevent starting. This may be a cleaner solution than interrupting the remote start circuit.4.

NEC Requirements for Service Disconnects

Remember that your EDS must meet all the requirements for service disconnects as outlined in Article 230 of the NEC, including:

Readily Accessible

It must be easily accessible to emergency responders.

Suitable for Service Equipment

It must be rated for use as service equipment.

Externally Operable

It must be operable from the outside of the house without opening the enclosure.

Clearly Marked

It must be clearly and permanently marked as an emergency disconnect.

In summary, while using the third pole of the EDS to interrupt the generator remote start circuit is potentially viable, it requires careful planning, proper wiring methods, and approval from your local AHJ. Consult with a qualified electrical professional to ensure a safe and code-compliant installation. Ignoring the NEC and potentially creating a dangerous situation is not an option. Flag for review