HIMA HIQuad H41X, Системное руководство, Страница: 28 / 110

Concept for HIQuad X System
Page 28 of 110 HI 803 211 E Rev. 1.01.00
3.5.2.2 Heat Dissipation
The following consideration can also be used to determine the power dissipation. Uniform
distribution of the heat load and unhindered natural convection are assumed.
Magnitude Description Unit
P
V
Power dissipation (heat capacity) of the electronic
components within the device W
A Effective enclosure surface (see below) m²
B Enclosure width m
H Enclosure height m
T Enclosure depth m
K
Coefficient of heat transfer of the enclosure W/m² K
Example: Steel plate Approx. 5.5 W/m²
K
Table 4: Definitions for Calculating the Power Dissipation
3.5.2.3 Installation Type
The effective enclosure surface area A as a function of the mounting or installation type is
determined as follows:
Enclosure installation type in accordance with VDE 0660, Part 5 Calculation of the enclosure surface A
Individual enclosure, free-standing on all
sides A = 1.8 x H x (W + D) + 1.4 x W x D
Individual enclosure for wall mounting
A = 1.4 x W x (H + D) + 1.8 x H x D
Final enclosure, free-standing
A = 1.4 x D x (W + H) + 1.8 x W x H
Final enclosure for wall mounting
A = 1.4 x H x (W + D) + 1.4 x W x D
Central enclosure, free-standing
A = 1.8 x W + H + 1.4 x W x D + H + D
Central enclosure, for wall mounting
A = 1.4 x W x (H + D) + H x D
Central enclosure, for wall mounting,
with covered roof area A = 1.4 x W + H + 0.7 x W x D + H + D
Table 5: Installation Types for Control Cabinets
3.5.2.4 Natural Convection
When natural convection is applied, the lost heat is dissipated through the enclosure walls.
Requirement: The ambient temperature must be lower than the temperature within the
enclosure.
The maximum temperature increase
ΔT
max
of all electronic devices within the enclosure is
calculated as follows:
ΔT
max
= P v / k x A
The power dissipation P
V
can be calculated based on the specifications for the electric power
rating of the controller and its inputs and outputs.
3.5.2.5 Note on the Standard
The temperature within an enclosure can also be calculated in accordance with VDE 0660, Part
507 (HD 528 S2).
i
Considerations about heat must take every component within a cabinet or enclosure into
account, including components that are not directly part of the HIQuad X system!