Question 1

What types of capacitors does Specap carry?

Accepted Answer

Specap stocks a comprehensive range of capacitors including aluminum electrolytic, film, ceramic, motor-run/start, tantalum, silver mica, and specialty capacitors. We carry both standard and hard-to-find components from over 30 major manufacturers. For a detailed comparison of different capacitor technologies, see our Capacitor Types guide at /resources/guides/capacitor-types.

Question 2

How long has Specap been in business?

Accepted Answer

Specap Electronics has been serving customers since 1984, giving us over 40 years of experience in capacitor distribution. Our expertise allows us to help customers find the right components for their applications.

Question 3

Do you offer technical support?

Accepted Answer

Yes, our experienced technical team is available Monday through Friday, 8am-5pm EST. We can help with part selection, cross-referencing, and application guidance. Call us at 1-800-SPECAP-1 or email support@specap.com.

Question 4

What is your minimum order quantity?

Accepted Answer

We have no minimum order quantity for most items. Whether you need 1 piece or 10,000+, we can accommodate your order. Volume pricing is available for larger quantities.

Question 5

Do you ship internationally?

Accepted Answer

Yes, we ship worldwide. International orders are shipped via FedEx or UPS with full tracking. Contact us for international shipping quotes and lead times.

Question 6

How do I request a quote?

Accepted Answer

You can request a quote through our online quote form, by emailing sales@specap.com with your part numbers and quantities, or by calling 1-800-SPECAP-1. We typically respond to quote requests within 4 business hours.

Question 7

What payment methods do you accept?

Accepted Answer

We accept Visa, Mastercard, American Express, Discover, wire transfers, and company purchase orders (subject to credit approval). Net 30 terms are available for qualified accounts.

Question 8

Do you offer volume discounts?

Accepted Answer

Yes, we offer tiered pricing based on quantity. Typical breakpoints are at 100+ and 500+ pieces, though this varies by product. Request a quote for specific volume pricing.

Question 9

Can I track my order?

Accepted Answer

Yes, once your order ships you will receive a tracking number via email. You can also track orders by logging into your account on our website.

Question 10

What is your return policy?

Accepted Answer

We accept returns within 30 days of purchase for unused items in original packaging. Custom orders and cut-tape items are non-returnable. Contact customer service to initiate a return.

Question 11

What is the difference between electrolytic and film capacitors?

Accepted Answer

Electrolytic capacitors offer high capacitance in a small package and are polarized, making them ideal for power supply filtering. Film capacitors have lower ESR, better stability, and longer life but larger size for the same capacitance. Film capacitors are preferred for AC applications and audio circuits. For an in-depth comparison, read our Electrolytic vs. Film Capacitors guide at /resources/guides/electrolytic-vs-film.

Question 12

How do I select the right voltage rating?

Accepted Answer

Select a capacitor with a voltage rating at least 20-50% higher than your maximum operating voltage. This derating ensures reliability and longer life. For applications with voltage spikes, additional derating may be necessary. Learn more in our Capacitor Derating guide at /resources/guides/capacitor-derating.

Question 13

What does ESR mean and why is it important?

Accepted Answer

ESR (Equivalent Series Resistance) is the internal resistance of a capacitor. Lower ESR means less power loss and heat generation. Low ESR is critical in switching power supplies and high-frequency applications. For a deeper dive, read our article Understanding ESR in Capacitors on the Specap blog at /resources/blog/understanding-esr-capacitors.

Question 14

What is ripple current rating?

Accepted Answer

Ripple current rating indicates the maximum AC current a capacitor can handle continuously without exceeding its temperature limits. Exceeding this rating causes premature failure. It's especially important in power supply filter applications.

Question 15

How do temperature ratings affect capacitor selection?

Accepted Answer

Capacitor life decreases as operating temperature increases. A 105°C rated capacitor will last longer than an 85°C rated capacitor in the same application. For every 10°C reduction in operating temperature, capacitor life approximately doubles. See our blog article on 85°C vs 105°C capacitors at /resources/blog/85c-vs-105c-capacitor-temperature-ratings for a detailed breakdown.

Question 16

Can I replace a capacitor with a higher voltage rating?

Accepted Answer

Yes, you can always use a capacitor with a higher voltage rating if it physically fits. However, capacitors with higher voltage ratings are typically larger. Never use a capacitor with a lower voltage rating than required.

Question 17

What is ESR in a capacitor?

Accepted Answer

ESR (Equivalent Series Resistance) is the total internal resistance of a capacitor, including lead resistance, electrode resistance, and electrolyte resistance. It causes power loss as heat when current flows through the capacitor. Low ESR is critical in switching power supplies, DC-DC converters, and any application with high ripple current. Typical ESR values range from a few milliohms for polymer capacitors to several ohms for general-purpose electrolytics. For a complete guide with ESR values by type, see our article on Understanding ESR in Capacitors at /resources/blog/understanding-esr-capacitors.

Question 18

Why do capacitors fail?

Accepted Answer

Capacitors fail for several reasons: excessive heat (the #1 killer, especially for electrolytics), voltage stress beyond ratings, ripple current exceeding specifications, age-related electrolyte dry-out, mechanical stress from vibration or thermal cycling, and manufacturing defects. Electrolytic capacitors are most prone to failure due to their liquid electrolyte, which slowly evaporates over time. Signs of failure include bulging, leaking, increased ESR, and loss of capacitance. For a detailed breakdown, see our Capacitor Failure Modes guide at /resources/blog/capacitor-failure-modes-prevention-guide.

Question 19

What causes capacitors to blow?

Accepted Answer

Capacitors blow (vent or rupture) when internal pressure exceeds the casing strength. This is caused by: applying reverse polarity to an electrolytic capacitor, exceeding the voltage rating (dielectric breakdown generates gas), excessive ripple current causing overheating, or a short circuit in tantalum capacitors that causes thermal runaway. Electrolytic capacitors have a vent score on top designed to release pressure safely. If you see a bulging or burst capacitor, always replace it and investigate the root cause before powering the circuit again.

Question 20

Can I use a 370V capacitor instead of 440V?

Accepted Answer

No, you should not use a 370V capacitor to replace a 440V capacitor. The voltage rating is the maximum safe operating voltage, and using a lower-rated capacitor risks dielectric breakdown and premature failure. However, the reverse is perfectly fine: you can always use a 440V capacitor to replace a 370V capacitor. The higher voltage rating provides additional safety margin. For HVAC applications, always match the microfarad (uF) value exactly and use an equal or higher voltage rating. See our complete guide at /resources/blog/370v-vs-440v-capacitors.

Question 21

Do electrolytic capacitors have a shelf life?

Accepted Answer

Yes, electrolytic capacitors have a limited shelf life, typically 2-3 years for aluminum electrolytics stored at room temperature. During storage, the aluminum oxide dielectric layer gradually degrades without the reforming voltage that normal operation provides. After extended storage, the capacitor may draw excessive leakage current when first powered. Capacitors stored longer than 2 years should be reformed by slowly applying voltage through a current-limiting resistor. Film, ceramic, and mica capacitors have essentially unlimited shelf life. See our Capacitor Shelf Life guide at /resources/blog/capacitor-shelf-life-storage-guide.

Question 22

What does a bad capacitor look like?

Accepted Answer

Visual signs of a bad capacitor include: a bulging or domed top (the most common sign in electrolytic capacitors), electrolyte leakage (brown or dark crusty residue around the base or vent), a cracked or split casing, burn marks or discoloration on the capacitor or surrounding PCB, and a detached or pushed-out rubber seal. For motor start capacitors, look for a swollen plastic case or oily residue. Not all bad capacitors show visible signs — capacitors can fail electrically (high ESR, low capacitance) while looking normal externally. When in doubt, test with a multimeter or ESR meter.

Question 23

What is tantalum capacitor polarity?

Accepted Answer

Tantalum capacitors are polarized and must be installed with correct polarity. For through-hole (dipped) tantalum capacitors, the positive lead is marked with a "+" sign or a stripe/band near the positive lead — this is the opposite of electrolytic capacitors where the stripe marks negative. For SMD tantalum capacitors, the positive end is marked with a bar or stripe on the case. Reversing polarity on a tantalum capacitor can cause catastrophic failure including short circuit and potential fire. See our Tantalum Capacitor Polarity guide at /resources/blog/tantalum-capacitor-polarity-guide.

Question 24

How do you read capacitor markings?

Accepted Answer

Capacitor markings vary by type. The most common system is the 3-digit code: the first two digits are significant figures and the third is a multiplier (number of zeros) in picofarads. For example, "104" = 10 + 0000 = 100,000 pF = 100 nF = 0.1 uF. Voltage is often a separate code letter (e.g., "J" = 63V). Tolerance is marked as a letter: J = 5%, K = 10%, M = 20%. Electrolytic capacitors typically print the value directly (e.g., "470uF 25V"). SMD capacitors use a similar 3-digit system or EIA-96 codes for 1% tolerance parts. See our complete decoding guide at /resources/blog/how-to-read-capacitor-markings-codes.

Question 25

What is the difference between X and Y safety capacitors?

Accepted Answer

X capacitors (X1, X2) are connected line-to-line (across the AC mains) and protect against differential-mode noise. Y capacitors (Y1, Y2) are connected line-to-ground and protect against common-mode noise. If an X capacitor fails short, it blows the fuse — inconvenient but safe. If a Y capacitor fails short, it connects the mains to the chassis, which is a shock hazard — so Y capacitors have much stricter safety ratings. X2 is the most common class for general appliances (up to 275V AC). Y2 is standard for basic insulation, while Y1 is required for reinforced insulation in medical and double-insulated equipment. See our full guide at /resources/blog/emi-emc-filter-capacitor-selection-guide.

Question 26

What are your shipping options?

Accepted Answer

We offer UPS Ground, UPS 2-Day, UPS Next Day Air, and FedEx services. Same-day shipping is available for orders placed before 2pm EST on in-stock items.

Question 27

How quickly do orders ship?

Accepted Answer

In-stock items ordered before 2pm EST ship the same day. Orders for items requiring manufacturing typically ship within 2-4 weeks. We'll provide estimated ship dates at the time of order.

Question 28

Do you offer expedited shipping?

Accepted Answer

Yes, we offer next-day and 2-day delivery options. For urgent requirements, call us directly and we'll do everything possible to meet your deadline.

Question 29

What if my order arrives damaged?

Accepted Answer

Document any damage with photos and contact us immediately. We'll arrange for replacement or refund. All shipments are insured for full value.

Question 30

Do you carry obsolete or hard-to-find parts?

Accepted Answer

Yes, hard-to-find and obsolete parts are our specialty. We maintain an extensive inventory of discontinued components and have relationships with manufacturers worldwide to source difficult parts. Browse our full catalog at /capacitors to see available inventory, including obsolete and legacy components.

Question 31

Are your capacitors genuine/authentic?

Accepted Answer

Absolutely. We are an authorized distributor for major manufacturers and source only from authorized channels. All components come with manufacturer documentation and are 100% guaranteed authentic.

Question 32

Can you help me find a replacement for a discontinued part?

Accepted Answer

Yes, our cross-reference tool and technical team can help find suitable replacements for discontinued parts. We'll match specifications to ensure compatibility with your application. You can also check our Capacitor Types guide at /resources/guides/capacitor-types to compare specifications across different technologies.

Question 33

Do you provide datasheets?

Accepted Answer

Yes, datasheets are available for most products on our website. Click the "Datasheet" link on any product page. For items without online datasheets, contact us and we'll provide the documentation.

Question 34

Do you offer custom or modified capacitors?

Accepted Answer

We can source custom specifications through our manufacturer relationships. Lead times vary by requirement. Contact us with your specifications for availability and pricing.

Question 35

How do I test a capacitor with a multimeter?

Accepted Answer

To test a capacitor with a multimeter, first safely discharge the capacitor. Set your multimeter to capacitance mode (if available) and measure across the terminals — the reading should be close to the rated value. You can also use resistance mode: a good capacitor will show low resistance that gradually increases. A short (zero ohms) or open (infinite resistance) reading indicates a failed capacitor. For a step-by-step walkthrough with photos, see our detailed guide: How to Test a Capacitor with a Multimeter at /resources/blog/how-to-test-capacitor-multimeter.

Question 36

What are the most common capacitor failure modes?

Accepted Answer

The most common capacitor failure modes include: electrolyte dry-out (in aluminum electrolytics, causing capacitance loss), dielectric breakdown (from overvoltage), ESR increase (leading to overheating), and mechanical failures such as bulging or leaking. Tantalum capacitors can fail short-circuit, which may cause a fire hazard. Environmental factors like heat, humidity, and voltage stress accelerate these failures. Read our complete guide on Capacitor Failure Modes and Prevention at /resources/blog/capacitor-failure-modes-prevention-guide for detailed prevention strategies.

Question 37

How do I know when a capacitor needs replacing?

Accepted Answer

Common signs that a capacitor needs replacing include: visible bulging or swelling of the case, electrolyte leakage (brown or dark residue), the equipment failing to start or running intermittently, humming or buzzing noises in motors or power supplies, reduced performance or efficiency, and frequent tripping of circuit breakers. In HVAC systems, a failing capacitor often causes the motor to hum without starting or to run sluggishly. For motor-specific troubleshooting, see our Motor Capacitor Troubleshooting guide at /resources/guides/motor-capacitor-troubleshooting.

Question 38

What is a visual sign of a start capacitor failure?

Accepted Answer

The most obvious visual sign of a start capacitor failure is a swollen or bulging plastic case. Motor start capacitors are enclosed in a plastic or Bakelite housing, and when they fail, internal pressure from gas buildup causes the case to expand, crack, or even burst open. Other visual signs include: oily residue leaking from the case (the dielectric fluid), burn marks or melted plastic, a pushed-out or displaced top vent, and in severe cases, a blackened or charred housing. If the motor hums but won't start and the capacitor looks normal externally, test it with a multimeter — it may have failed open without visible damage.

Question 39

How do I choose the right capacitor type for my application?

Accepted Answer

Choosing the right capacitor depends on your application requirements. For power supply filtering, aluminum electrolytic capacitors offer high capacitance at low cost. For AC coupling, signal filtering, and timing circuits, film capacitors provide excellent stability and low losses. Ceramic capacitors are ideal for high-frequency bypass and decoupling. For harsh environments or high-reliability applications, consider film or polymer capacitors. Our Capacitor Types guide at /resources/guides/capacitor-types covers each technology in detail with recommended applications.

Question 40

What is capacitor derating and why does it matter?

Accepted Answer

Capacitor derating means operating a capacitor below its maximum rated voltage and temperature to extend its lifespan and improve reliability. A common practice is to derate voltage by 20-50%, meaning a capacitor in a 100V circuit should be rated for 150-200V. Temperature derating is equally important — for every 10°C below the rated temperature, electrolytic capacitor life approximately doubles. Derating is especially critical in high-reliability applications such as medical devices, aerospace, and industrial controls. See our comprehensive Capacitor Derating guide at /resources/guides/capacitor-derating for derating curves and best practices.

Question 41

How do I size a motor capacitor?

Accepted Answer

Motor capacitor sizing depends on the motor type, horsepower, voltage, and whether you need a start or run capacitor. Start capacitors are typically 70-300 µF for single-phase motors and are only energized briefly during startup. Run capacitors are usually 5-60 µF and stay in the circuit during operation. Using the wrong size can cause poor motor performance, overheating, or failure to start. Use our Motor Capacitor Sizing Calculator at /resources/calculators/motor-capacitor-sizing to find the correct capacitor for your motor specifications.

Question 42

What capacitor do I need for my HVAC system?

Accepted Answer

HVAC systems typically use run capacitors rated at 370V or 440V AC. Common sizes include 5-80 µF for compressor motors and 5-10 µF for fan motors. Dual-run capacitors combine both in one package. Always match the microfarad (µF) rating exactly to the original — using the wrong value can damage the compressor. Voltage can be equal to or higher than the original. Check the nameplate on your existing capacitor or the equipment data plate for the correct specifications. For help with troubleshooting, see our HVAC Capacitor Troubleshooting guide at /resources/blog/hvac-capacitor-troubleshooting-replacement.

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