Mitsubishi Electric FR-A820-00046 (0.4K), Instruction Manual

Page: 44 / 1218

Installation of the inverter and enclosure design Installation and wiring
2 - 14
Dust, dirt, oil mist
Dust and dirt will cause such faults as poor contacts, reduced insulation and cooling effect due to the
moisture-absorbed accumulated dust and dirt, and in-enclosure temperature rise due to a clogged fil-
ter. In an atmosphere where conductive powder floats, dust and dirt will cause such faults as mal-
function, deteriorated insulation and short circuit in a short time.
Since oil mist will cause similar conditions, it is necessary to take adequate measures.
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Countermeasure
– Place the inverter in a totally enclosed enclosure.
Take measures if the in-enclosure temperature rises. (Refer to page 2-15.)
– Purge air.
Pump clean air from outside to make the in-enclosure air pressure higher than the outside air
pressure.
Corrosive gas, salt damage
If the inverter is exposed to corrosive gas or to salt near a beach, the printed board patterns and parts
will corrode or the relays and switches will result in poor contact.
In such places, take the measures given in "Dust, dirt, oil mist".
Explosive, flammable gases
As the inverter is non-explosion proof, it must be contained in an explosion-proof enclosure. In places
where explosion may be caused by explosive gas, dust or dirt, an enclosure cannot be used unless it
structurally complies with the guidelines and has passed the specified tests. This makes the enclosure
itself expensive (including the test charges). The best way is to avoid installation in such places and in-
stall the inverter in a non-hazardous place.
High altitude
Use the inverter at an altitude of within 1000 m. For the installation at an altitude above 1,000 m up to
2,500 m, derate the rated current 3% per 500 m.
If it is used at a higher place, it is likely that thin air will reduce the cooling effect and low air pressure
will deteriorate dielectric strength.
Vibration, impact
The vibration resistance of the inverter is up to 5.9 m/s² (2.9 m/s² or less for the FR-A840-04320(160K)
or higher) at 10 to 55 Hz frequency and 1 mm amplitude for the directions of X, Y, Z axes. Applying vi-
bration and impact for a long time may loosen the structures and cause poor contacts of connectors,
even if those vibration and impacts are within the specified values.
Especially when impacts are applied repeatedly, caution must be taken because such impacts may
break the installation feet.
●
Countermeasure
– Provide the enclosure with rubber vibration isolators.
– Strengthen the structure to prevent the enclosure from resonance.
– Install the enclosure away from the sources of the vibration.