R.m.s. values
From Electrical Installation Guide
The r.m.s. value of voltage and current can be calculated as a function of the r.m.s. value of the various harmonic components:
[math]\displaystyle{ I_{rms} = \sqrt {\sum_{h=1}^{H}I_h^2 } = \sqrt {I_1^2 + I_2^2 + \dots + I_H^2 } }[/math]
[math]\displaystyle{ V_{rms} = \sqrt {\sum_{h=1}^{H}V_h^2 } = \sqrt {V_1^2 + V_2^2 + \dots + V_H^2 } }[/math]