Computer Grade Capacitors - Finding The Right Capacitor

• CGS (85C computer grade standard)
• CG (85C long life computer grade)
• CGR (105C computer grade high temp)
• CGO (85C computer grade low leakage)
• DCMC (85C computer grade low ESR)
• DCM (85C computer grade low ESR high ripple current)
• Type 500 (85C computer grade long life)
• Type 100 (105C computer grade low ESR)
• Type 101 (105C computer grade low ESR)
• 36D (85C computer grade standard)
• 36DX (85C computer grade standard)
• 23A (85C computer grade standard)
• 23M (85C computer grade low ESR high ripple current)
• 3186 (85C computer grade standard)
• 3188 (105C computer grade long life)

Typically large can computer grade capacitors will have a capacitance measured in microfarads (mfd) or the designation uF. This capacitance is represented in numbers (example 10,000 mfd or 25,000 uF). Next you will see a voltage on the unit, designated by a V or WVDC (working voltage). 99% of the time, these capacitors are measured in DC (direct current) voltages. This is the constant voltage these capacitors will withstand.

Important in replacing these capacitors is not only the capacitance and voltage but also the size of the unit. The diameter of these capacitors comes primarily in the following diameters (in inches):

• 1.375 (1 3/8)
• 1.750 (1 3/4)
• 2.0
• 2.5 (2 1/2)
• 3.0

In most cases these large can electrolytic capacitors are mounted to either board or chasis with round clamp VR series.

95% of the cans will fall into these categories. The height of the units can vary from 2.125 to 8.75 inches.

An important piece of information about large can electrolytics is their tolerances. Typically voltages from 6 volts to 150 volts have a tolerance of -10% +75%. This is important because a capacitor of 10,000 mfd at 50 volts can, in actuality, read on the positive side up to 17,500 mfd and be within tolerance. So when choosing a replacement capacitor, typically you have the flexibility to choose a mathematically suitable replacement. Above 150 volts up to 450 volts the typical tolerance is -10% +50% again, giving you flexibility when choosing a computer grade capacitor replacement.

These capacitors typically come with a PVC insulating sleeve.