String-Level Monitoring Calculator

Calculate the number of current transformers (CTs) and monitoring hardware needed for string-level PV monitoring.

Input Parameters

Results

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Total CTs Required
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Number of Combiners
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Monitor Channels
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CT Size Rating
A
Note: String-level monitoring detects underperforming strings within minutes. Split-core CTs allow retrofit installation. Typical accuracy: ±1% for revenue-grade monitoring.

Reference

CTs required = 1 per string Combiners = ceil(Strings / Inputs_per_combiner) Monitor channels = CTs + Combiner channels (3 each) CT rating ≥ Isc × 1.25 (rounded to 5A) NEC 690.8 current correction factor