User guide
Xenus Plus User Guide    Regen Resistor Sizing and Configuration 
Copley Controls  128 
Choose a resistor with a power rating equal to or greater than the calculated continuous power. 
Verify that the calculated power value is less than the continuous regen power rating specified in 
Regen Circuit Output (p. 61). 
A.1.11: Select Fuses 
For custom regen resistors, Cooper Bussman KLM fuses, or equivalent, should be selected. The 
peak and continuous currents, as well as the peak current time, must be taken into consideration 
for proper fuse selection. The duration of the peak current is the deceleration time (Tdecel) 
associated with the maximum pulse power regen event. 
Use the following formulas to determine the minimum peak and continuous current ratings of the 
fuse. For related drive specifications, see Regen Circuit Output (p. 61). 
The peak current is determined by the chosen regen resistor value. 
I
peak
 = V
regen
 / R
regen
Where: 
I
peak
 = The current though the regen resistor during regeneration in Amps. 
V
regen
 = The voltage at which the regen circuit turns on. 
R
regen
 = The resistance value of the chosen regen resistor in Ohms. 
The continuous current is determined by the continuous regen power. 
I
cont
 = P
cont
 / V
regen
Where: 
I
cont
 = The minimum continuous current rating the fuse requires in Amps. 
P
cont
 = The continuous power calculated in the previous step, in Watts. 
V
regen
 = The voltage at which the regen circuit turns on. 










