Plans and checks emergency/standby power system design against NFPA 110's Type/Class classification framework: whether a UPS can bridge the gap until the generator is ready (the 'bridge check'), and whether a staged sequence of load steps can be picked up by the generator without exceeding its single-step acceptance limit or violating NFPA 110's priority-order (700/701/702) restoration-time requirements.
Standards followed
NFPA 110 (emergency and standby power systems)ISO 8528 (reciprocating internal combustion engine driven AC generating sets, referenced by the general method)
What it can do
- NFPA 110 Type classification from required maximum interruption time, and Class from required minimum runtime.
- UPS-to-generator bridge timing check: genset ready time (start delay + crank-to-rated + transfer time) versus available UPS/battery autonomy, with a 25% margin flag.
- Staged load-step pickup planner checking single-step generator acceptance percentage, cumulative loading, and NFPA 110 priority-order (700 emergency / 701 legally-required standby / 702 optional standby) sequencing.
Example problem
A Level 1 facility requires a maximum 10-second interruption and 48-hour minimum runtime. The genset takes 1.5s ATS start delay + 10s crank-to-rated + 0.3s transfer time, bridged by a UPS with 30s of autonomy. Three load steps of 50kW, 130kW and 280kW connect in priority order.
- 10s max interruption → NFPA 110 Type 10.
- 48h min runtime → NFPA 110 Class 48.
- Genset ready time = 1.5 + 10 + 0.3 = 11.8s.
- Bridge check: 11.8s required vs. 30s UPS autonomy available — passes, with (30−11.8)/11.8 ≈ 154% margin (well above the 25% flag threshold).
- Load steps connect in ascending priority order (emergency → legal → optional) with no step exceeding the generator's single-step acceptance limit.
Type 10 / Class 48 classification, bridge check passes with >25% margin, load sequence has no priority-order or step-size warnings.
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