Voltage Regulator & Slope:

Many of Caterpillars generator sets have optional voltage regulators (e.g. CDVR), or the standard regulator (e.g.

VR6) may be adjustable for various degrees of slope. This slope is the ratio of the percent voltage change to the

percent of frequency change.

As an example, a 2:1 regulator will reduce voltage 2% for each percent of frequency change. This control is a

volts/hertz optimization and allows choosing between the standard (Price List) regulator and slope, or an optional

choice with a larger slope (for example 3:1). Depending on load scenario details, either might result in a smaller,

less costly SpecSizer recommended generator set.

The program default selection is Best Fit, which selects the regulator that results in selecting the smaller

generator set. "Best Fit" compares the generator set's transient response as tested with the adjustable voltage

regulator at 3:1 slope versus tested with the standard voltage regulator at 2:1 or 1:1 slope. If both regulator

selections recommend the same size generator set, the Standard regulator is chosen, since this is the common

regulator and the user is not required to specify the adjusted voltage regulator when ordering a generator set.

Either way, SpecSizer's Project Sizing Report as well the Select Generator Set page will note which voltage

regulator was specified for the SpecSizer recommended generator set.