Installation of the converter and enclosure design
30
Humidity
Operate the multifunction regeneration converter within the ambient air humidity of usually 45 to 90% (up to 95% with circuit
board coating). Too high humidity will pose problems of reduced insulation and metal corrosion. On the other hand, too low
humidity may cause a spatial electrical breakdown. The insulation distance defined in JEM 1103 "Control Equipment
Insulator" is humidity of 45 to 85%.
(a)
Measures against high humidity
• Make the enclosure enclosed, and provide it with a hygroscopic agent.
• Provide dry air into the enclosure from outside.
• Provide a space heater in the enclosure.
(b)
Measures against low humidity
Air with proper humidity can be blown into the enclosure from outside. Also when installing or inspecting the unit, discharge
your body (static electricity) beforehand, and keep your body away from the parts and patterns.
(c)
Measures against condensation
Condensation may occur if frequent operation stops change the in-enclosure temperature suddenly or if the outside air
temperature changes suddenly.
Condensation causes such faults as reduced insulation and corrosion.
Measures
• Take the measures against high humidity in
(a)
.
• Do not power OFF the converter. (Keep the start signal of the inverter OFF.)
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 filter. In an 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.
Measures
• Place the converter in a totally enclosed enclosure.
Take measures if the in-enclosure temperature rises. (Refer to
• 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 converter 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 the previous paragraph.
Explosive, flammable gases
As the multifunction regeneration converter 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 converter in a non-hazardous place.
High altitude
Use the multifunction regeneration converter at an altitude of within 2500 m. For use at an altitude above 1000 m, consider a
3% reduction in the rated current per 500 m increase in altitude.
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.
Summary of Contents for FR-XC-11K
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