You're asking a crucial question about the compliance of your essential electrical system (EES) in your outpatient facility, specifically regarding separation of loads within panelboards. Let's break down the requirements based on NFPA 99 (Healthcare Facilities Code) and NEC (National Electrical Code), along with industry best practices.

Key Considerations



NFPA 99 applicability

The most critical question is whether your outpatient facility is required to comply with NFPA 99. This depends on the types of procedures performed and the level of risk associated with those procedures.

Essential Electrical System (EES) Requirements

If NFPA 99 applies, your EES must adhere to its requirements for redundancy, separation, and prioritized power to specific systems.

Panelboard Separation

NFPA 99 does not require physically separation panelboard for critical branch, equipment branch and life safety branch, but it requires circuit identification in a panelboard. So if NFPA 99 is applicable it is best to separate the panelboard for critical, equipment and life safety as it is better for maintenance in future.

Analysis of Your Situation (Based on Information Provided)


Outpatient, Non-Hospital

Since you're specifically stating it's not a hospital, the applicability of NFPA 99 hinges on the procedures performed within your outpatient facility. If your facility performs procedures that would put patients at risk of potential life threatening procedures, NFPA 99 is applicable. Otherwise it does not need to be.2.

Single ATS, Less Than 150 kVA

Having a single Automatic Transfer Switch (ATS) for your EES is generally permissible for smaller facilities.3.

Mixed Panelboard Loading

The problem arises from having a mixture of equipment, critical, and life safety support loads all fed from the same panelboards. This is generally not allowed.

NFPA 99 and Load Separation (If Applicable)

If NFPA 99 applies to your facility, the following principles of EES are highly relevant:

Prioritization

The EES is designed to prioritize power to systems essential for patient safety during a utility power outage. Life safety loads should be powered first, followed by critical branch loads and then equipment branch loads.

Separation

NFPA 99 mandates functional separation of these load types. This means that a fault or failure in one branch (e.g., equipment branch) should not impact the operation of the other branches (critical and life safety).

Minimizing Commingling

Commingling of the loads within the panelboards is not allowed.

Circuit Identification

If commingling of loads cannot be avoided, NFPA 99 requires clear labeling and identification of circuits related to critical, life safety, and equipment branches.

Why Mixed Panelboards are Problematic (if NFPA 99 applies)



Potential for Cascade Failures

A fault in an equipment branch circuit could potentially trip the main breaker of the panelboard, taking down critical and life safety loads as well.

Compliance Difficulties

It becomes very difficult to ensure the required prioritization and separation of power to different load types when they're all fed from the same panelboard.

Maintenance and Testing Complications

Troubleshooting and maintenance become more complex and risky when you're working on a panelboard that powers life safety systems.

Inspection Issues

Inspectors will likely flag this as a violation of NFPA 99 requirements.

Recommendations


Determine NFPA 99 Applicability

First, definitively determine if NFPA 99 applies to your outpatient facility based on the procedures performed.2.

If NFPA 99 Applies



Separate Panelboards

The best approach is to separate the loads onto dedicated panelboards for the different branches (critical, equipment, life safety). This provides the greatest level of separation and compliance.

Careful Circuit Mapping and Labeling

If separation is absolutely impossible, meticulously map out every circuit in your existing panelboards and ensure that all circuits are clearly labeled according to their load type (critical, equipment, or life safety).3.

Consult an Electrical Engineer

Engage a qualified electrical engineer experienced in healthcare electrical systems to review your current design and provide recommendations for compliance with NFPA 99. They can assess the feasibility and cost of different separation options.
4.

Consider Redundancy

If possible, add more redundancy to your power system, such as having separate power sources for critical loads.

In summary

While NFPA 99 does not mandate separate panelboards for critical branch, equipment branch and life safety branch, the recommended best practice is to separate the loads onto dedicated panelboards for the different branches (critical, equipment, life safety). This provides the greatest level of separation and compliance.

Important Notes: I am an AI and cannot provide official interpretations of codes or regulations. Consult with qualified professionals.* Local codes and regulations may have additional requirements beyond NFPA 99 and the NEC. Flag for review