For the amount of heat generated by the inverter unit, refer to page 41 . 1 Humidity Operate the inverter within the ambient air humidity of usually 45 to 90% (up to 95% with circuit board coating). Too high 2 humidity will pose problems of reduced insulation and metal corrosion. On the other hand, too low humidity may cause a spatial from Control Equipment" is 45 to 85%. electrical breakdown. The humidity conditions for the insulation distance defined in JEM 1103 standard "Insulation Distance 3 Measures against high humidity Make the enclosure enclosed, and provide it with a hygroscopic agent. 4 Provide dry air into the enclosure from outside.
Measures against low humidity Provide a space heater in the enclosure. 5 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. 6 Measures against condensation temperature changes suddenly. Condensation may occur if frequent operation stops change the in-enclosure temperature suddenly or if the outside air 7 Condensation causes such faults as reduced insulation and corrosion. Take the measures against high humidity. Do not power OFF the inverter.
(Keep the start signal of the inverter OFF.) Dust, dirt, oil mist 8 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 9 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. Countermeasure 10 Place the inverter in a totally enclosed enclosure. Purge air. Take measures if the in-enclosure temperature rises.
(Refer to page 42 .) 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 the previous paragraph. 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 installation in such places and install the inverter in a non-hazardous place. passed the specified tests. This makes the enclosure itself expensive (including the test charges). The best way is to avoid High altitude Use the inverter 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. 39 2.
INSTALLATION AND WIRING 2.3 Installation of the inverter and enclosure design NOTE