Protection Coordination Guide — Time-Current Curves Poster
Free download · A3 landscape (420 × 297mm)
Protection coordination is best understood visually. This A3 poster presents overlaid time-current characteristic curves for a typical industrial system: utility relay → main MCCB → feeder MCCB → motor starter. CTI (Coordination Time Interval) zones are shaded between curves, instantaneous pickup bands are highlighted, and coordination rules are annotated directly on the diagram. A sidebar covers the five most common coordination errors and how to spot them. Essential for protection engineers, power system designers, and anyone involved in relay settings review.
What's Included
How to Print
- ●Print on A3 (297 × 420mm) or tabloid (11 × 17")
- ●Color printing required for comparison highlights
- ●Use a professional print shop for best results
- ●Frame or laminate for long-term office display
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Frequently Asked Questions
What paper should I print this on?
Print on A3 paper in color (minimum 100gsm). The colour-coded curves are essential for understanding the coordination margins.
Can I distribute this to my team?
Yes. Print copies for your protection engineering team. All ECalPro posters are free to print and distribute within your organization.
What standard does this reference?
Time-current curves per IEC 60255-151 (relay characteristics) and IEC 60947-2 (circuit breaker tripping curves). CTI values per IEEE C37.112.
How often is this updated?
Updated when protection relay or circuit breaker standards are revised. Coordination principles are stable.