Mitsubishi Electric 700 Series, Instruction Manual

Page: 19 / 416

8
Installation of the inverter and
enclosure design
1.4 Installation of the inverter and enclosure design
When an inverter enclosure is to be designed and manufactured, heat generated by contained equipment, etc., the
environment of an operating place, and others must be fully considered to determine the enclosure structure, size and
equipment layout. The inverter unit uses many semiconductor devices. To ensure higher reliability and long period of
operation, operate the inverter in the ambient environment that completely satisfies the equipment specifications.
1.4.1 Inverter installation environment
As the inverter installation environment should satisfy the standard specifications indicated in the following table,
operation in any place that does not meet these conditions not only deteriorates the performance and life of the
inverter, but also causes a failure. Refer to the following points and take adequate measures.
*1 2.9m/s
2
or less for the FR-F740-04320 or more.
(1) Temperature
The permissible surrounding air temperature of the inverter is -10
°C (14°F)
to +50
°C (122°F)
(when LD is set) or -10
°C
(14°F)
to +40
°C (104°F)
(when SLD is set). Always operate the inverter within this temperature range. Operation outside
this range will considerably shorten the service lives of the semiconductors, parts, capacitors and others. Take the
following measures so that the surrounding air temperature of the inverter falls within the specified range.
1) Measures against high temperature
• Use a forced ventilation system or similar cooling system. (Refer to page 10.)
• Install the enclosure in an air-conditioned electrical chamber.
• Block direct sunlight.
• Provide a shield or similar plate to avoid direct exposure to the radiated heat and wind of a heat source.
• Ventilate the area around the enclosure well.
2) Measures against low temperature
• Provide a space heater in the enclosure.
• Do not power OFF the inverter. (Keep the start signal of the inverter OFF.)
3) Sudden temperature changes
• Select an installation place where temperature does not change suddenly.
• Avoid installing the inverter near the air outlet of an air conditioner.
• If temperature changes are caused by opening/closing of a door, install the inverter away from the door.
(2) Humidity
Normally operate the inverter within the 45 to 90% range of the ambient humidity. Too high humidity will pose problems
of reduced insulation and metal corrosion. On the other hand, too low humidity may produce a spatial electrical
breakdown. The insulation distance specified in JEM1103 "Control Equipment Insulator" is defined as humidity 45 to
85%.
1) Measures against high humidity
• Make the enclosure enclosed, and provide it with a hygroscopic agent.
• Take dry air into the enclosure from outside.
• Provide a space heater in the enclosure.
2) Measures against low humidity
What is important in fitting or inspection of the unit in this status is to discharge your body (static electricity)
beforehand and keep your body from contact with the parts and patterns, besides blowing air of proper humidity into
the enclosure from outside.
3) 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.
• Take the measures against high humidity in 1).
• Do not power OFF the inverter. (Keep the start signal of the inverter OFF.)
Environmental standard specifications of inverter
Item Description
Surrounding air temperature
LD -10 to +50°C (14°F to 122°F) (non-freezing)
SLD(Initial setting) -10 to +40°C (14°F to 104°F) (non-freezing)
Ambient humidity 90% RH maximum (non-condensing)
Atmosphere Free from corrosive and explosive gases, dust and dirt
Maximum Altitude 1,000m (3280.80 feet) or less
Vibration
5.9m/s
2
or less
*1
at 10 to 55Hz (directions of X, Y, Z axes)