Large horsepower variable frequency drive
Most of what we do is larger horsepower.. and we have done some single phase input drives in applications up to 350 HP (its rare).. so you may be correct in not needing more capacitors at 1 HP.. we seldom do anything in that range.. However, in larger HP's, the capacitor ripple is an issue.. it heats the capacitors.. its not uncommon to open a single phase input drive and find capacitor goop all over the bottom of the cabinet.. These are typically 50 HP and above that we see.. we would in no circumstance put a single phase drive in without either adding capacitors (which is done in the irrigation industry commonly) or up-sizing the drive. With VFD costs being as low as they are (and getting lower), we would usually opt for a bigger drive.
Capacitors are the number one component failure in large drives.. (we're rebuilding a 1500 HP medium voltage drive right now that has blown caps), heat is the primary culprit... and ripple equals heat.. (the 1500 HP is obviously not single phase)
Capacitors are the number one component failure in large drives.. (we're rebuilding a 1500 HP medium voltage drive right now that has blown caps), heat is the primary culprit... and ripple equals heat.. (the 1500 HP is obviously not single phase)
