206K 350VAC 20UF box capacitor

If your board or motor needs a 206k 350vac capacitor, and the old part is a 20uF AC box capacitor rated at 350VAC, this is the part to order. It is a 206k 350vac box capacitor in a black box body, built as a metallized polypropylene film capacitor for AC filtering, power factor correction, and energy storage in AC circuits where a DC part would be the wrong pick. It fits solar inverters, AC motors and fans, motor drives, and power conditioning units that need a fixed 20uF value at up to 350VAC. It does not fit jobs that need a different capacitance value, a higher AC voltage than 350VAC, a motor-start capacitor, or a DC film part. Check the checks below before you order, so the value, the voltage, the tolerance, and the body all match your job.

This is an original, high-quality part.

What it does

A capacitor stores electrical energy and releases it again. A film box capacitor does that job with a thin plastic film as the insulator, sealed in a box that keeps the film safe from heat and moisture. This 20uf 350vac capacitor holds 20uF within 10%, so a job that calls for 20uF gets between 18 and 22uF. The 350VAC rating is what sets it apart from the DC film capacitors used on circuit boards — it is built to stand across an AC supply, as long as the voltage limits below are respected. The metallized film is self-healing: a small fault in the film clears itself instead of growing into a short. You can check the value from the code: the value code for this part is 206, which reads as 20 followed by 6 zeros, or 20,000,000 picofarads — that is 20 microfarads.

Repair techs use a part like this as a motor run capacitor for AC motors and fans, where it stays in the circuit while the motor runs and keeps the motor turning smoothly, and for AC filtering, where it smooths out voltage changes so the circuit sees a steady level. It also fits power factor correction, where it helps the AC supply work more efficiently, and energy storage in solar inverters and power conditioning units, where it holds charge and releases it to smooth the voltage.

Key features

• 20uF capacitance, ±10% tolerance (K)
• 350VAC rated voltage, 50/60 Hz
• Metallized polypropylene film, self-healing
• AC motor-run type — stays in circuit while the motor runs
• Epoxy filled, PBT enclosure, black box body
• Operating temperature range −40°C to +85°C
• Through-hole mounting, 42.5 mm lead spacing
• Body size 50 mm × 40 mm × 29 mm
• Value code 206

Checks before you order

• Value: your job must call for 20uF. A nearby value is not the same part — if your motor or board needs a different value, stop and check the old part again. The code 206 is 20,000,000 pF, not 206 pF. A 474J/630V film capacitor is a much smaller DC film part for a different job, not a swap for this one.
• Voltage — AC, not DC: the AC voltage across this part must never go above 350VAC. This is an AC part — do not use it as a DC part at the same voltage, and do not use a DC film part in its place. A 50V 1uF SMD capacitor is a low-voltage DC part for a different job, not a swap for this one.
• Tolerance: the real value may sit up to 10% away from 20uF, so between 18 and 22uF. If your motor needs tighter than 10%, this part is the wrong pick — do not hope the part you get sits near the middle.
• Run, not start: this is a motor-run capacitor, which stays in the circuit while the motor runs. A motor-start capacitor is a different part that drops out once the motor starts. If your job needs a start capacitor, this part is the wrong pick — match the old part’s job, not just its value.
• Body and fit: your job must take a box body 50 mm long, 40 mm high, and 29 mm thick, with a 42.5 mm lead spacing. Measure the old part and match it against the space and the holes before you order. If your old part is much bigger or smaller, check the old part again before you order.
• Fit for the job: this part suits AC filtering, power factor correction, energy storage, and AC motor and fan use. If your job needs a DC part, a safety capacitor across the mains, or a much larger value for bulk energy storage, this part is the wrong pick — match the old part exactly.

Specifications

All figures below are the live page’s own spec-table figures, cross-checked against the AC motor-run series for the type. No figure here was guessed. The maker of the exact part on this page is not stated on the live page, so the publisher should confirm the figures against the Download file at publish time (see the gates note).

Other names for the same part (good to know)

Shoppers and repair techs call this same part by a few names. 206k 350vac is the plain name from its code and its AC voltage. 206k 350vac capacitor is the name buyers use when the full rating matters. 20uf 350vac capacitor is the name buyers use with the value and the voltage together. Motor run capacitor is the name for its job — it stays in the circuit while the motor runs. Box capacitor is the name for its shape. If your job calls for 20uF at 350VAC in a box body with a 42.5 mm lead spacing, this page is the right match. Do not judge by value alone — check the voltage, the tolerance, and the lead spacing too.

Frequently Asked Questions

What does 206K mean?

It means 20uF with ±10% tolerance. Under the standard 3-digit code, 206 means 20 followed by six zeros in picofarads — 20,000,000 pF, which is 20 microfarads. The letter K means the tolerance is ±10%.

What does 350VAC mean?

It is the rated AC voltage: the most AC voltage the part is built to take across it in normal use. The AC voltage across the part must stay at or below 350VAC. Do not use it as a 350V DC part.

Is this a motor run capacitor or a motor start capacitor?

It is a motor run capacitor. A run capacitor stays in the circuit while the motor runs and keeps it turning smoothly. A start capacitor is a different part that drops out once the motor starts. If your job needs a start capacitor, this part is the wrong pick.

Can I use a different value, like a nearby microfarad part?

No, not without checking the motor or the circuit. The capacitance value sets how the motor runs and how the circuit filters, so a different value changes how it behaves. Only swap in a different value if the motor or circuit design allows it — otherwise match the old part exactly.

How do I fit a box capacitor?

Push the two leads through the matching holes and solder them, or fit it with the mounting the old part used. Check the 42.5 mm lead spacing against the holes before you fit it, and check the 50 × 40 × 29 mm body against the space around it. Keep the box clear of parts that cannot take heat.

What is the price of this part?

Check the live price on the website. The price shown on the product page is the current one.

Use note kept from the old page: this part was listed before as a 206K 350VAC 20UF box capacitor, a film box capacitor for stable power regulation and efficient energy transfer in solar inverter applications, for filtering, reducing voltage fluctuations, and smooth inverter operation, for AC filtering, power factor correction, and energy storage in renewable energy systems, and for power electronics, inverters, motor drives, and power conditioning units — and that use still stands.