In procurement, we often hear this: "A capacitor is a capacitor." We get it — they all store energy, right? But here's what we've seen time and again: the wrong capacitor choice can mean hours of unplanned downtime at a power facility, or a five-figure maintenance bill for a machine park that nobody saw coming.
At JGS, we've worked alongside hundreds of procurement specialists over the years. In this post, we share the five questions you should ask — together with your technical team — before every capacitor order.
The most common mistake: selecting a capacitor that matches the nominal operating voltage exactly. In industrial applications, momentary voltage spikes are unavoidable. For safe sourcing, we recommend choosing a class at least 20% above the nominal voltage. For example, in a 400V grid system, a minimum 500V — preferably 630V — rated capacitor will both extend service life and prevent unexpected failures.
Capacitor lifespan is directly linked to temperature. For electrolytic capacitors, every 10°C increase in temperature halves the expected service life — this is the well-known Arrhenius Rule in electronics. In your procurement process, always ask:
• Will the capacitor be inside a control cabinet or exposed to the open environment?
• What is the maximum ambient temperature during summer months?
• How close will it be positioned to heat sources such as motors, transformers, or inverters?
In power factor correction applications, accurately determining the reactive power demand is the most critical step. Undersizing leads to insufficient compensation during load peaks; oversizing creates unnecessary cost and resonance risk. Requesting electrical distribution diagrams and power analyzer reports at the procurement stage helps avoid both extremes.
4. Are the Mounting and Connection Conditions Suitable?
Vibration resistance for film capacitors, mounting orientation for aluminum electrolytics, discharge resistor requirements for MKP types — each technology brings its own installation requirements. Following the mounting instructions specified in the technical datasheet is also critical for maintaining warranty coverage.
Buying a capacitor is a transaction. Selecting the right capacitor is a process. At JGS, every quotation is prepared with your application's technical specifics in mind. From sizing calculations through to post-installation field follow-up, our technical team is there with you every step of the way.
At JGS, we've worked alongside hundreds of procurement specialists over the years. In this post, we share the five questions you should ask — together with your technical team — before every capacitor order.
1. What Voltage Class Do You Actually Need?
The most common mistake: selecting a capacitor that matches the nominal operating voltage exactly. In industrial applications, momentary voltage spikes are unavoidable. For safe sourcing, we recommend choosing a class at least 20% above the nominal voltage. For example, in a 400V grid system, a minimum 500V — preferably 630V — rated capacitor will both extend service life and prevent unexpected failures.
2. What Is the Ambient Temperature Range?
Capacitor lifespan is directly linked to temperature. For electrolytic capacitors, every 10°C increase in temperature halves the expected service life — this is the well-known Arrhenius Rule in electronics. In your procurement process, always ask:
• Will the capacitor be inside a control cabinet or exposed to the open environment?
• What is the maximum ambient temperature during summer months?
• How close will it be positioned to heat sources such as motors, transformers, or inverters?
3. Has the Reactive Power Requirement Been Calculated Correctly?
In power factor correction applications, accurately determining the reactive power demand is the most critical step. Undersizing leads to insufficient compensation during load peaks; oversizing creates unnecessary cost and resonance risk. Requesting electrical distribution diagrams and power analyzer reports at the procurement stage helps avoid both extremes.
4. Are the Mounting and Connection Conditions Suitable?
Vibration resistance for film capacitors, mounting orientation for aluminum electrolytics, discharge resistor requirements for MKP types — each technology brings its own installation requirements. Following the mounting instructions specified in the technical datasheet is also critical for maintaining warranty coverage.
5. Does Your Supplier Offer Application Support?
Buying a capacitor is a transaction. Selecting the right capacitor is a process. At JGS, every quotation is prepared with your application's technical specifics in mind. From sizing calculations through to post-installation field follow-up, our technical team is there with you every step of the way.