Best Way to Satisfy Plan Reviewer without Load Calculation



1. Provide Vendor Specifications

Submit the vendor's specifications for the new x-ray machine, which should include its load requirements. This will demonstrate that the new equipment's load (125A) conforms to the manufacturer's specifications.

2. Reference Existing Panel Capacity

Explain that the existing 400A MLO panel has a sufficient capacity to accommodate the new 125A breaker. Provide supporting documentation, such as the panel's label or engineering calculations, to demonstrate this.

3. State Limited Load Information

Acknowledge that comprehensive load information for the existing panel is not available. Explain that the absence of as-built documentation is a common challenge in these scenarios.

4. Offer Alternative Verification

If possible, propose an alternative method to verify the panel's load capacity, such as: Thermal imaging (if the panel is accessible) Phase and load balancing studies Infrared scanning

5. Seek Approval for Limited Design Exception

Explain to the plan reviewer that the urgent timeline and lack of load information make it challenging to perform a detailed load calculation. Request approval for a limited design exception that assumes the existing panel's capacity is adequate based on the vendor specifications and limited available information.

Regarding Metering

While metering is a valuable method for load verification, the 30-day requirement is not applicable in all jurisdictions. Contact the local electrical inspector to determine if metering is required and what the specific time frame is.

Additional Tips: Communicate openly and professionally with the plan reviewer, explaining the situation and proposed solutions. Be prepared to provide additional documentation or explanations as requested.* Emphasize the safety and functionality of the proposed design, based on vendor specifications and limited available information. Flag for review