Chart
ITIC-style voltage sag and swell tolerance envelope
Use an ITIC-style curve to understand voltage sag, swell, dropout, and equipment ride-through discussions.
Does not diagnose a site event, prove equipment tolerance, set utility obligations, or replace power-quality monitoring.
itic envelope
Duration and voltage magnitude zones
A short deep sag and a long shallow sag can have different equipment effects; the two axes must be read together.
Can reset controls or electronics.
Duration and magnitude must be read together.
Not proof of equipment tolerance.
Overvoltage stress depends on duration.
Decision table
Show how event duration and voltage magnitude combine to create power-quality risk zones for Canadian users reviewing sag and swell records.
Scroll sideways to keep row labels aligned with hidden columns.
| Curve band | What it shows | Risk cue | Handoff |
|---|---|---|---|
| Interruption zone | Very low voltage event | Dropout or reset | Power-quality monitor data |
| Sag zone | Reduced voltage for a duration | Motor contactor or drive trip | Equipment ride-through review |
| No-interruption band | Typically tolerated area | Equipment-specific exceptions | Manufacturer data |
| Swell zone | Elevated voltage event | Overvoltage stress | Utility/power-quality review |
Notes
- Treat this chart as a planning and conversation aid only.
- Confirm current utility requirements, product markings, manufacturer instructions, and local authority requirements before field work.
- Use the linked calculator or table when the task needs project-specific arithmetic.
Source links
Open the underlying public sources before treating the chart as project guidance.