☑ Y Capacitor Design

Many appliances today have a ground lead that connects their chassis and metal cases to an electrical ground or neutral. If they short circuit the risk is a shock to the user.

Safety Capacitors First Class X And Class Y Capacitors

If they short circuit the risk is fire.

Y capacitor design. Class y capacitors conduct at failure this is a safety issue. Vicor products including farm arm and vi brick ac front end have filters that include y capacitors. To be clear you should select your class x and class y capacitors according to your designs purpose and requirements.

Dont you think a class x capacitor should have been used so that the user would be protected in case of a failure. My question is why did the manufacturer use a class y capacitor for the isolation stage. Devices that plug into an ac mains outlet need protection from emi.

The iec60601 1 explicitly states that the use of y capacitor only provide one mopp means of patient protection and actually two mopp is required. The pi ac input filter. A pi filter as shown in figure 1 is often used for this application.

Whereas x2 and y2 caps are appropriate for household applications x1 and y1 safety capacitors are used in industrial settings. Indeed the isolation issue lies on the use of y capacitor on the smps. How are y capacitors used with vicor products.

In short using y capacitor you never archieve the isolation requirement. Because of the risks x and y capacitors are safety agency tested. The list of parts included may be found below.

This line to ground configuration uses class y capacitors. The dual functions of x and y emi capacitors safety standards govern xy input filter design. Refer to the farm design guide and application manual for an example of an integral input filter comprising a common mode choke y capacitors and x capacitors.

One line filtering design places a capacitor between one of the ac lines coming in and the appliances chassis. Quantity varies per part number according to physical size. Design a kemet x or y capacitor into your next project.

Other back to basics posts. In basically every data sheet a 01uf is indicated as a general rule of thumb. X capacitors are across the line.

Using two by pass capacitors normally a decade apart in value is called compound by passing. Y capacitors are from line to chassis. Ic b uses two by pass capacitors a small value ceramic 01uf and a larger value tantalum capacitor 22uf for example.

Kemet is offering this emi or x and y capacitor kit to meet your needs for testing and design with a variety of common capacitor values.