Samlex America PSE-24275A - Manual (Page 14)

Page 13
LIMITING ELECTRO-MAGNETIC INTERFERENCE
(EMI)
The inverter contains internal switching devices which generate conducted and radiated
electromagnetic interference (EMI). The EMI is more pronounced in inverters whose
output voltage has modified sine wave form as modified sine wave form is composed of
odd harmonics of the fundamental frequency. These harmonics may produce buzzing
sound in inexpensive stereo systems because the power supply of these systems does not
provide adequate filtration. In such cases, use stereo systems with better quality power
supply.
The magnitude of EMI is limited to acceptable levels by circuit design but can not be
entirely eliminated. The effects of EMI will also depend upon a number of factors
external to the power supply like proximity of the inverter to the EMI receptors, types
and quality of connecting wires and cables etc. EMI due to factors external to the inverter
can be reduced as follows:
- Ensure that the inverter is firmly grounded to the ground system of the building or the
vehicle
- Locate the inverter as far away from the EMI receptors like radio, audio and video
devices as possible
- Keep the DC side cables between the battery and the inverter as short as possible.
- Twist the DC side cables. This will partially cancel out the radiated noise from the
cables
- Shield the DC side cables with metal sheathing / copper foil / braiding
- Use co-axial shielded cable for all antenna inputs (instead of 300 ohm twin leads)
- Use high quality shielded cables to attach audio and video devices to one another
- Do not operate other high power loads when operating audio / video equipment