Mitsubishi Electric F700, Instruction Manual

Page: 17 / 341

8
Installation of the inverter and
enclosure design
(3) Dust, dirt, oil mist
Dust and dirt will cause such faults as poor contact of contact points, reduced insulation or reduced cooling effect due
to moisture absorption of accumulated dust and dirt, and in-enclosure tempearture rise due to clogged filter.
In the atmosphere where conductive powder floats, dust and dirt will cause such faults as malfunction, deteriorated
insulation and short circuit in a short time.
Since oil mist will cause similar conditions, it is necessary to take adequate measures.
Countermeasures
•• Place in a totally enclosed enclosure.
Take measures if the in-enclosure temperature rises. (Refer to page 9.)
•• Purge air.
Pump clean air from outside to make the in-enclosure pressure higher than the outside-air pressure.
(4) 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 Section (3).
(5) 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 install the inverter in a non-hazardous place.
(6) Highland
Use the inverter at the altitude of within 1000m.
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.
(7) Vibration, impact
The vibration resistance of the inverter is up to 5.9m/s
2
(2.9m/s
2
for the 04320 or more) at 10 to 55Hz frequency
(directions of X, Y, Z axes) and 1mm amplitude.
Vibration or impact, if less than the specified value, applied for a long time may make the mechanism loose or cause
poor contact to the connectors.
Especially when impact is imposed repeatedly, caution must be taken as the part pins are likely to break.
Countermeasures
•• Provide the enclosure with rubber vibration isolators.
•• Strengthen the structure to prevent the enclosure from resonance.
•• Install the enclosure away from sources of vibration.