Why make things complicated?
You can make very accurate ripple measurements by simply attaching a large valued, (1-100F) high-voltage electrolytic capacitor to the 460 voltage supply of interest to a 1 meg resistor to ground. Insert a 1K ohm in series with the 1meg and capacitor common meas. point. At the other side of the 1K resistor just connected, connect two 12V zener diodes in series to ground. Connect the zeners back to back, (anode to anode), one side to ground the other to the test point.
Note: if you use a very large valued electrolytic cap, it may take some seconds for this coupling capacitor to charge up through the zener protection network before you will see a clear oscilloscope reading.
These two zeners and the 1K connected together will protect your scope from any possible overload, so then just attach the x10 scope probe to junction of the 1k and the two zeners and at this test point you can safely measure the exact 460V supply ripple on your scope without any chance of damaging your scope. If the observed ripple waveform is clipped, you might know at that point your power supply needs new filter caps, otherwise add another pair of 12V zeners back to back in series with the two already to give you a +-24V Peak to Peak dynamic range of absolutely safe measurement