A couple general questions about DCV to ACV

Without going into the integral calculus behind root mean squared computations, realize that RMS voltage is the equivalent steady DC voltage that would produce the same heat dissipation in a resistor as the waveform for which the RMS value is calculated. While any periodic or random voltage waveform will have an RMS value, it is most common that RMS values are derived from a sine wave, i.e., AC voltage. The peak value of a sine wave is related to its RMS value by the square root of two (1.414) or its inverse (0.707). Note that polarity makes no difference since negative voltage produces the same amount of heat as positive voltage. Peak=1.414*RMS, RMS=0.707*Peak

In your questions the DC voltage represents a peak value, while you are trying to find the RMS value of AC voltage which has that same peak value.

 

1. What setting would you use on AC to test 2000VDC peak voltage?

I suppose you are referring to the setting of a voltmeter. You cannot set the voltmeter to AC when testing a 2,000-Volt DC voltage. You need to set it to DC setting that has a maximum scale of 2,000 VDC or more.

RMS Value? 2,000 VDC has no RMS value. RMS values refer only to AC. So you can't set your voltmeter to RMS and measure a DC voltage like 2,000 VDC.

2. If you are testing an alternistor rated at 600 volts DC, what do you set the AC tester for? Again, AC tester is for measuring AC voltage. If you want to measure Dc voltage then you have to use a DC voltmeter.