power supply

How dependable are transformer specs?

A Single phase 0-115-230V primary 24VAC secondary connected to a
bridge rectifier and 15,000uF capacitor should produce 33 VDC. The
actual output was 46VDC. The culprit? On checking the transformer
secondary, the output was 33VAC instead of the specified 24VAC. Is
this common experience?

Based on what had been so emphatically put across recently, one
should have no hesitation on using this power supply despite it being
out of specs - voltage being so unimportant for steppers, right?

Just to be on the safe side - what size zener diode should one place
across the output?

Peter

BTW one should take care to discharge the capacitor, say, across an
incandescent lamp at end of test.