Power Entry Module

KFA Compact with filter and now with ground line choke

In addition, the newly added ground line choke improves asymmetric attenuation in higher frequencies in medical filter versions. The KFA series with existing common-mode choke on the phase and neutral conductors, together with an additional ground line choke, is well enhanced to address the growing EMC challenges facing compliance engineers today.

Ground loops arise through different impedances of different ground line connections in one or multiple pieces of equipment. While all ground connections have the same potential level for the 50 Hz load current, these can have different potential levels for high-frequency interference. The ground line choke, which is wired between the power-inlet connector and the filter output, smartly addresses this phenomenon. Because of its placement directly at the power line input, high-frequency interference currents on the ground line are prevented from bypassing the filter through the equipment housing. The ground line choke isolates the equipment chassis against high frequencies and the equipment ground from the ground on the line power connection. This approach effectively breaks any possible ground loop.

Audio equipment for instance is known for being prone to ground loop problems. Often referred to as hum or buzz, the KFA, with ground line choke, is well suited for suppressing interferences that lead to diminished sound quality. The KFA is also well suited for medical equipment required to use low leakage filters for increased patient safety. The reduced Y capacitance to ground, or absence thereof, leads to reduced asymmetric attenuation in higher frequencies. The KFA with ground line choke helps to compensate for this reduced performance.

The KFA power entry module includes an IEC C14 power inlet connector with a 1- or 2-pole fuseholder and EMC filter and is available in a wide range of models and designs. The series offers current levels from 1A to 10A at 250 VAC according to IEC and UL standards. The series has ENEC and cURus approvals and is suited for applications according to IEC 60950. Special filter versions, M5 and M80, are available for medical devices according to IEC 60601-1. Wiring is done using quick-connect terminals or wire leads. The KFA is compatible with V-Lock cord sets, designed to safeguard against unintentional disconnection of the power.

SCHURTER’s compact KEA series power entry module, with 1- or 2-pole fuseholder, now mates with V-Lock cord sets. The KEA’s new V-Lock compatible feature prevents unintended disconnection of the power from the equipment.

Unlike wire bail or clamp accessories, no additional costly hardware is necessary to install the cord retaining system. The cord set safely latches into a notch in the plastic housing of the KEA. Removing the cord set is easily achieved by depressing the latch. V-Lock power cords are offered in a wide range of international plugs.

The KEA is ideal for audio equipment, especially equipment used on stage, where the power to the equipment must withstand mechanical stress on the cord. It features C14 inlet, 1- or 2-pole fuseholder for 5 x 20 mm fuses, 4.8 x 0.8mm quick-connect or PCB terminals, and screw-on or snap-in mounting. Optional voltage selector allows for use in analog equipment exported to international markets. Current rating is 10 A at 250 VAC. The alternate KFA series with EMC line filter is available with current ratings of 1, 2, 4, 6 and 10 A at 125 VAC UL/250 VAC IEC. This series offers an integrated ground line choke to protect against ground loop interferences. Approvals include UL, CSA, VDE and CCC.

With the V-Lock cord retaining system, the cordset safely latches into a notch in the plastic housing of the KEA module. Removing the cordset is easily achieved by depressing the latch. V-Lock power cords are offered in a wide range of cord lengths and country-specific plugs.

The loss of the power supply may have serious consequences for analytical, diagnostic or laboratory equipment in medical technology, mobile measuring instruments, professional audio and video equipment or devices in the food industry. Particularly in the case of electrical appliances that are moved during operation, there is a risk that the mains cable may be unintentionally disconnected from the appliance. Cord retention safety devices can prevent this.

The most common type of cord retention devices are Cord retaining strain reliefs. Depending on the type of appliance plug and the large number of different types of appliance sockets, the correct bracket shape must be selected here.