Technical Foundation
What Are Capacitors?
A capacitor is defined by a short list of numbers — capacitance, voltage rating, tolerance, temperature range and package — and the correct replacement is the one that matches all of them. Substituting on capacitance alone is the classic mistake: a 370V run capacitor in a 440V position will fail, usually quickly and messily.
ChatMRO indexes over 1.8 million capacitors, from oval motor-run cans for HVAC condensers to surface-mount ceramics in reel quantities. The catalogue is attribute-complete, so "45/5 uF 440V dual round" resolves to a shortlist immediately, and so does a bare manufacturer part number. Ripple current and ESR rarely appear on a basic spec sheet, but they decide whether a replacement survives in a switching power supply or fails within weeks of installation.
For obsolete or single-sourced parts, ChatMRO compares candidate replacements against the original on every rated parameter and shows exactly where they diverge — ripple current, ESR, endurance hours — so the substitution is an engineering decision rather than a guess.
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| Spec | What It Means | Why It Matters |
|---|---|---|
| Capacitance | The rated value in microfarads or picofarads | The primary match, but never sufficient on its own for a safe substitution |
| Voltage Rating | The maximum voltage the capacitor is rated to withstand | Under-rating this is the single most common cause of premature, sometimes violent failure |
| Tolerance | The allowable deviation from the rated capacitance value | Tighter tolerances matter in timing and filter circuits, less so in motor-run applications |
| Ripple Current | The rated AC current the capacitor can dissipate as heat | Exceeding it shortens life dramatically, especially in switching power supplies |
| ESR | Equivalent series resistance at the rated frequency | Higher ESR than the original means more self-heating and a shorter service life |
Shop Capacitors
Browse Capacitors Sub-Categories
1.8M parts, organised the way a maintenance store is. Pick a sub-category, or skip it entirely and just describe the part you need.
How it works
From Half-Remembered Part Number to PO, in Three Steps.
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Type an MPN, paste a spec sheet, or describe the part in plain English. ChatMRO understands engineer-speak.
Compare
Side-by-side specs, cross-references, and equivalents from multiple sources — without the clutter of endless browser tabs.
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Request a quote or add to cart. Volume discounts, VAT-aware pricing, and consolidated procurement — all in one place.
Applications
Where Capacitors Get Used
The same component behaves differently by sector, because the duty cycle, the environment and the paperwork all change.
HVAC & refrigeration
Dual run capacitors serving compressor and condenser fan from one can, plus start capacitors with potential relays on hard-start applications.
Single-phase motor equipment
Pumps, compressors, blowers and machine tools using capacitor-start or capacitor-start capacitor-run configurations.
Variable speed drives & power conversion
DC link and output filtering where ripple current and ESR govern life far more than nominal capacitance.
Industrial control panels
Power supply filtering, snubbers across contactor coils and inrush suppression, mostly film and aluminium electrolytic types.
Lighting & ballasts
Power factor correction within discharge lighting gear and film capacitors in electronic drivers.
Electronics manufacturing & repair
Surface-mount ceramic, tantalum and polymer types selected by dielectric class, package and bias behaviour.
Plant power distribution
Power factor correction banks sized in kVAR and increasingly detuned to survive harmonic-rich supplies.
Welding, induction & pulse equipment
High ripple and high peak current duty where specialised film constructions with heavy-current terminations are required.
Brands
Capacitors Brands in the Catalogue
Cross-reference freely between them — ask for an equivalent and ChatMRO shows what matches and what differs.
FAQ
Capacitors Questions, Answered
Can I substitute a higher voltage capacitor?
For most applications yes — a higher voltage rating at the same capacitance is a safe upward substitution, provided the package still fits. Going the other way is not. ChatMRO flags the difference on every suggested equivalent.
Do you carry obsolete and end-of-life capacitors?
The catalogue includes long-tail and legacy parts, and where the original is genuinely unavailable ChatMRO proposes replacements compared parameter by parameter against the discontinued item.
Can I search by capacitance and voltage instead of part number?
Yes. Describe it the way it is printed on the can — for example "35/5 uF 370V dual round" — and ChatMRO returns matching parts across manufacturers.
Are reel and bulk quantities available?
Yes. Enter the quantity you need in the quote request and pricing reflects reel, tray or bulk breaks automatically.
How do I know a replacement will fit physically?
Every result carries case dimensions and termination style. Ask ChatMRO to compare the footprint against your original and it will show both side by side.
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