Yaskawa i80M Connecting Manual - Manual (Page 10)

4.2 CABINET DESIGN FOR HEAT FACTORS
The cabinets used to contain the CPU module and other units should be designed so that they
are of totally-enclosed construction and the difference between the inner-air temperature and
ambient temperature is less than 10”C.
In designing the cabinets, also take the following into
consideration.
(1) Air Temperature Rise inside Cabinet (Average Temperature Rise)
Air temperature rise inside the cabinet made of sheet metal is
lows:
Air temperature rise inside cabinet
P: Heat generated by electric appliance (W)
: Cabinet heat transmission
K: Sheet metal-metal transmission “C)
6W/m 20 C : With a circulating fan
4W/m 20 C : Without a circulating fan
A: Effective radiation area cabinet (m z )
generally determined as
Surface area of the cabinet through which heat can be radiated.
(Surface area that contacts other objects is excluded)
(Example) Allowable Heat Value inside Cabinet with a Circulating Fan
o Where the heat value generated inside the cabinet is
o
180W
:
P P
( “ c )
Since the value calculated above is less than the allowable temperature rise of 10”C, the
design works just fine. When the value is more than 10”C, a separate method for
quired.
(2) Cooling Capacity of Heat Exchanger
When a circulating fan installed inside the cabinet is not sufficient, the following
gers are available.
cooling is re-
heat
Heat Exchanger Cooling Capacity Dimensions
REX1 550 100WX1O”C 295W X 890H X
—
HEATEX02 250W X 10”C 440W X 924H X
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