Mitsubishi Electric MDS-E Series Instruction Manual page 65

MDS-E/EH Series Instruction Manual
1 Installation
The following shows a calculation example for considering heat radiation countermeasures.
< Control panel outline dimension (assumption) >
When installing four units which have the heating value in the panel of 15W
Heat radiation area (A): When a bottom section contacts with a machine
A = 0.6 × 0.3 ＋ 0.6 × 0.6 × 2 ＋ 0.6 × 0.3 × 2 = 1.26 (m )
(Top face) (Front/back face)
(Note) Actually, sections contacting other objects are excluded.
Heating value in panel (W): when installing four units which are 15W
W = 15 × 4 = 60 (W)
< Considering necessity of agitating fan >
1 Temperature standard
(1) Standard of temperature in panel (around each unit) T ≦ 55°C
(2) External peripheral temperature
(3) Internal temperature rise value
2 Cooling capacity of control panel (W1)
W1 = U × A × DT
(1) With internal agitating fan
(2) Without internal agitating fan W1 = 4 × 1.26 × 10 = 50.4 (W) < 60 (W) -- Internal fan is required.
POINT
Measure an actual internal temperature, and install a fan or heat exchanger which agitates the heat at the top of the unit if
the temperature rise exceeds 10°C.
IB-1501229-F
Top of panel inside
600
(Side face)
DT = Internal temperature rise value (=10°C)
2
U = 6W/m • °C (with internal agitating fan)
2
4W/m • °C (without internal agitating fan)
A = Effective heat radiation area (m
W1 = 6 × 1.26 × 10 = 75.6 (W) > 60 (W)
34
Fan for agitating
300
2
Ta = 0 to 45°C
DT = T - Ta (MAX) = 10°C
2
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