By Jay Prigmore II, Ph.D., P.E. Last reviewed · Prepared and reviewed by a licensed Professional Engineer
Testifying and consulting expert services in electrical engineering disputes — retained by plaintiff and defense counsel, insurers, owners, and manufacturers in matters exceeding $10 billion in aggregate dispute value.
By Jay Prigmore II, Ph.D., P.E. Last reviewed · Prepared and reviewed by a licensed Professional Engineer
Electrical failures produce disputes that turn on technical questions a jury cannot evaluate unaided: why a transformer failed, whether a protective device should have cleared a fault, whether an arc flash study was performed to the governing standard, or whether a maintenance program met the standard of care. PEFG is retained to answer those questions and to defend the answer under cross-examination.
Engagements are handled personally by Jay Prigmore, Ph.D., P.E. — there is no junior staff performing the analysis and no principal signing work they did not do. The same person who inspects the evidence writes the report and gives the testimony.
Opposing experts routinely disagree about how a standard should be applied. PEFG's principal is a voting member of the IEEE 1584 working group — the committee that writes the arc flash calculation standard itself — and a founding member of the NFPA Technical Committee on Electrical Inspection Practices.
That is a materially different position from having read the standard. When the dispute is about what the standard requires or how its equations were intended to be applied, the person who participated in writing it is difficult to impeach on that point.
At Exponent, Jay led more than 400 forensic investigations and served as a testifying expert in over 15 litigation and arbitration matters. From 2020 to 2025 he led electrical quality and field reliability engineering for Google's global hyperscale data center fleet, building the incident-response and forensic-analysis functions that investigate failures across live, mission-critical infrastructure.
That combination matters in deposition. Consulting-only experts can be challenged on whether they have operated real equipment at scale; operations-only experts can be challenged on methodology. This background answers both lines of attack.
PEFG accepts retention nationwide and works for either side of a dispute. Because engagements are not routed through a staffing process, a conflict check and retention letter can typically be turned around in one to two business days — which matters when evidence is at risk of being disturbed.
A 4,160 V motor feeder faults; the plant loses production for eleven days; the owner sues the maintenance contractor. Everyone agrees the cable failed. The dispute is whether the upstream relay should have cleared it before the cable burned back into the switchgear.
The opinion is not built from the pleadings. It is built from the relay’s own record: the event file gives fault current magnitude and the actual clearing time in cycles. Those two numbers get compared against the relay’s as-found setting file, and the setting file against the coordination study of record. If the study called for an instantaneous element that the setting file does not contain, the question stops being metallurgical and becomes documentary — who changed the setting, when, and under whose authority.
If the settings match the study, the analysis moves upstream: was the study itself correct? A short-circuit model reconstructed from the as-built one-line will show whether the fault current at that location was inside the range the study assumed. Each step narrows the disputed issue, and each step is independently checkable by the other side’s expert — which is the point.
Where the arithmetic behind an opinion is publishable, it is published. The derivations and calculators at PowerEngCalc — including the IEEE 1584 incident energy calculator and the 2018-versus-2002 edition comparison — have been public and unchallenged for years. A method that has been on the open record long before the engagement is materially harder to characterize as result-driven than one that first appears in a Rule 26 report.
Questions that come up before a retention decision, answered by the engineer who would do the work.
Two distinct jobs, and they are usually phased. As a consulting expert, the work is to tell retaining counsel what the evidence actually shows — including when it does not support the theory of the case. As a testifying expert, the work is to form an opinion to a reasonable degree of engineering certainty, disclose it in a Rule 26 report, and defend it in deposition and at trial. The technical analysis is the same; the disclosure obligations are not. PEFG will say early and plainly when the engineering does not support the position being advanced, which is more useful before an expert designation than after it.
Before the evidence moves. Electrical evidence is unusually perishable: relay and meter event records overwrite on a rolling buffer measured in days or weeks, SCADA historians age out on a retention schedule, and failed switchgear gets cleaned, repaired, or scrapped as part of getting a facility back into production. An engineer involved before the equipment is disturbed can establish origin and cause far more defensibly than one working from photographs taken by someone who was not looking for the same things. Retention can happen before liability theories are settled — a preservation protocol costs very little and cannot be re-created later.
Scope, not hourly rate. The largest cost drivers are the number of site inspections, whether laboratory examination or destructive testing is required, the volume of documents to be reviewed, and the number of depositions. PEFG bills hourly on a time-and-expense basis, with deposition and trial testimony billed at a higher rate than analysis and report work, which is standard practice. Scope is phased and separately authorized — document review, site inspection, laboratory work, and report are each budgeted before they start, so there is no open-ended exposure and no surprise invoice.
Both, and deliberately so. Retention is accepted from plaintiff and defense counsel, insurers, owners, and manufacturers. An expert whose testimony history sits entirely on one side of the bar invites an obvious line of cross-examination, and it is not one worth handing over. Every engagement begins with a conflict-of-interest check against the full party list before any substantive discussion of the matter.
The same things that make it correct: a method published by a recognized body rather than invented for the case, inputs traceable to primary evidence rather than to counsel's summary, calculations that can be reproduced by the other side from the report alone, and explicitly stated assumptions with a sensitivity analysis where an assumption is doing real work. Committee membership helps here in a specific way — when the dispute is about what a standard requires or how its equations were intended to be applied, the person who participated in drafting it is difficult to impeach on that point.
Typically one to two business days. Engagements are not routed through an intake coordinator or a staffing process; the party list is checked and the retention letter is issued by the same engineer who will do the work. If physical evidence is at immediate risk, a written preservation protocol is issued in parallel with the paperwork rather than after it.
Direct principal access. Conflict check within one to two business days.