One of the most frequent questions engineers ask before inspecting Diesel / Gas Generator Inspection is: "Which standard should I cite on the certificate, and where do the pass/fail limits come from?" This reference guide maps NFPA 110 to national regulatory adoptions and provides the complete standard annex tables.
1. National & Regional Standard Equivalence Matrix
| Region / Language | Adopted National Standard & Regulatory Code |
|---|---|
| International / UK (EN) | NFPA 110 |
| Turkey (TR · Türkçe) | TS ISO 8528-5 / NFPA 110 / Binaların Yangından Korunması Yön. |
| Germany / DACH (DE · Deutsch) | DIN EN ISO 8528-5 / VDE-AR-N 4105 / NFPA 110 |
| France (FR · Français) | NF ISO 8528-5 / NF E 37-312 / NFPA 110 |
| Spain (ES · Español) | UNE-ISO 8528-5 / REBT ITC-BT-28 / NFPA 110 |
| Italy (IT · Italiano) | UNI ISO 8528-5 / DM 22/10/2007 / NFPA 110 |
| Gulf / Middle East (AR · العربية) | NFPA 110 / SASO / DEWA / ADDC |
2. Normative Acceptance Criteria & Mathematical Basis
Acceptance: a Type 10 EPSS must start and accept load within 10 s (NFPA 110 Table 4.1(b)). Steady-state and transient frequency / voltage bands follow the ISO 8528-5 performance class selected below.
P_min_exercise: P_min = 0.30 x P_rated [kW] — Minimum monthly exercise load required by NFPA 110 §8.4.2 to prevent diesel engine wet-stacking.
3. Official Standard Reference Tables
ISO 8528-5 Table 4 & Table 5: Generator Performance Class Limits (ISO 8528-5 / NFPA 110)
| Performance Class | Application | Steady-State Freq Band | Transient Freq Dip (100% step) | Freq Recovery Time | Transient Voltage Dip |
|---|---|---|---|---|---|
| Class G1 | Basic lighting & simple mechanical loads | +/- 2.5% | <= 18% | <= 10 s | <= 25% |
| Class G2 | Commercial buildings, pumps, fans (utility-like) | +/- 1.5% | <= 12% | <= 5 s | <= 20% |
| Class G3 | Data centers, UPS rectifiers, hospital life-safety, telecom | +/- 0.5% | <= 10% | <= 3 s | <= 15% |