The start capacitor in a motor control box is considered a consumable part. Capacitors tend to lose capacitance over time and/or use, and need to be replaced when the capacitance drops below the described range.
This start capacitor is fully compatible for replacing Pentair Pentek, Myers, Sta-Rite start capacitors with part number: U17-1423 , CMCI 59MFD+20%/-0% , Start cap in Tuhorse TCB15M230, and other control boxes that use the same rating start capacitor. Some older control box's start capacitor is 270V, this 330V, higher withhold voltage version is the same or better. We now stock the 330V version only.