Engineering tools
Engineering tools
Four tools built on the formulas in this portal and the cited standards. Use them for orders of magnitude and to judge results — they do not replace the on-site diagnostic.
Panel planner (end-user panel)
Apply the allocation rule to one end-user panel: enter its principal breaker and its outgoing breakers.
Principal (incoming) breaker
Outgoing breakers
Applied case
Mixed: some 60 A and above, some below
Plates for this panel
9
1 plate per phase conductor on each breaker ≥ 60 A; principal breaker fitted when any outgoing breaker is below 60 A. Site totals come from the survey or SLD.
HF loss in a cable[9[9] Novitskiy et al., 2020Supraharmonic losses in MV/LV cables.,10[10] Mariscotti & Mingotti, 2024Supraharmonics, cable losses and partial-discharge activity.]
Extra I²R loss when part of a conductor's current flows at high frequency. Single isolated copper conductor; proximity effect is ignored, so real losses are usually higher.
R_AC / R_DC at HF
× 59.9
50/60 Hz loss
353.7 W
HF loss
13.2 W
HF share of cable loss
3.6 %
HF loss energy per year
79 kWh
Annulus approximation R_AC ≈ ρ / (π(2rδ − δ²)) for δ < r, ρ = 1.68×10⁻⁸ Ω·m. Lower-bound estimate.
Insulation life vs temperature rise[3[3] IEEE Std 1-2000General principles for temperature limits in the rating of electrical equipment and for the evaluation of electrical insulation (Arrhenius thermal ageing).,5[5] Aarniovuori et al., IECON 2013Induction motor losses under converter supply (+8.7% to +19% total losses).,6[6] Jiang et al., 2022Winding temperature rise and additional losses under high-frequency harmonics.]
Relative insulation life under the 10 °C halving rule (IEEE Std 1-2000).
Relative life
56 %
Expected life
11.3 y
Extra loss, 37 kW motor (≈41 W per °C, Aarniovuori et al.)
+340 W
Engineering rule of thumb for thermal ageing; actual life depends on insulation class, duty and other stresses.
Savings uncertainty (ASHRAE Guideline 14)[15[15] EVO — IPMVPInternational Performance Measurement and Verification Protocol, Options B and C.,16[16] ASHRAE Guideline 14Measurement of energy, demand and water savings.]
Fractional savings uncertainty of a regression baseline. A saving is statistically meaningful when its uncertainty is well below the saving itself.
t-statistic (df = 10)
1.05
Fractional savings uncertainty
± 21 %
Uncertainty is below 50% of the savings at this confidence — meets the ASHRAE Guideline 14 criterion.
ΔE/E = 1.26 · t · CV · √((n/n′)(1 + 2/n)(1/m)) / F, with n′ = n (no autocorrelation). ASHRAE Guideline 14: uncertainty below 50% of savings at 68% confidence.