3. General Specifications (Environment Conditions)
3.5 Heat Radiation Countermeasures
14
3.5 Heat Radiation Countermeasures
Please refer to the following method for heat radiation countermeasures.
<Hypothetical conditions>
(1) Average internal temperature of operation panel: T
≤
55°C
(2) Peripheral temperature of operation panel
: Ta
≤
0°C to 45°C
(3) Internal temperature rise value
:
Δ
T =
T–Ta
(
max
) = 10°C
<Supplement>
(1) Refer to "3. General Specification" for the heat
generated by each unit.
(2) Enclosed cabinet (thin steel plate) cooling
capacity calculation equation
W1 = U × A ×
Δ
T
U: 6 W/m
2
°C
A: Effective heat radiation area (m
2
)
Δ
T: Internal temperature rise value (10°C)
(Area where heat can be radiated from
operation panel)
<Caution>
8 W/m
2
°C can be applied only when the
operation panel is so small that the internal
temperature stays uniform.
(3) Points of caution for heat radiation
countermeasures when designing mounting
state
* Consider convection in operation panel
(eliminate heat spots)
* Collect hot air at suction port of heat
exchanger in operation panel.
(4) Criterion for internal temperature rise
distribution data
Δ
T (average value)
≤
10°C
Δ
T
max
(maximum value)
≤
15°C
R (inconsistency
Δ
T
max
–
Δ
T
min
)
≤
6°C
(Evaluate existence of heat spots)
Procedures for heat design and verification
Example of heat radiation countermeasures
Calculate total heat radiation of each
mounted unit (W)
Comparison of W and W1
W
≤
W1
Collection of internal temperature rise
distribution data
Mounting design
Improvements
Completion
Selection of heat exchanger
Evaluation
W>W1
Δ
T
≤
10°C
Δ
T>10°C
Calculate cooling capacity of
operation panel (W1)
