Hioki IM3570 - Appendix 6 the Residual Charge Protection Function

Appendix 6 The Residual Charge Protection Function
A10
The unit has been enhanced by the incorporation of a residual charge protection function. If by mistake a
charged capacitor is connected to the measurement terminals, this function protects the internal circuitry of
the unit from discharge of such residual charge.
The maximum voltage from which the unit can be protected by this function is determined from the capaci-
tance value of the sample under test by the following equation:
V: voltage (volts) (maximum 400 VDC)
C: capacitance (farads)
Appendix 6 The Residual Charge Protection
Function
V
10
C
------
=
• The quoted maximum voltage from which the unit can be protected by this function is for
reference purposes only, and is not a guaranteed value. There may be danger of dam-
age to the unit, depending upon the operational circumstances and upon how often such
charged capacitors are connected. In general, you should not rely upon this protection
function; be sure to discharge charged capacitors properly before connecting them to the
test terminals.
• The residual charge protection function is for protection of the unit against the discharge
of voltage present in charged capacitors, and is not capable of protecting the unit against
DC voltage which is constantly applied such as a superimposed DC voltage. If this is
done, there is a danger of damage to the unit.
See: Appendix 5 Supplying DC Bias (p.A7)