iec 890 (1987 amd 1 1995-02)
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.
RAPPORT
TECHNICAL
TECHNIQUE -TYPE
3
REPORT
-
TYPE
3
CE1
IEC
890
1987
AMENDEMENT 1
AMENDMENT 1
1995-02
Amendement 1
Mthode de dtermination par extrapolation
des chauffements pour les ensembles
d appareillage basse tension
drivs de srie (EDS)
Amendment 1
A method
of
temperature-rise assessment
by extrapolation for partially-tested
assemblies (PTTA) of low-voltage
switchgear and controlgear
0
CE1
1995
Droits
de reproduction
rservs
- opyright -
ail ngMs
reserved
BureauCentrai de iaCommission Eledrotechnique Intematinale 3. rue
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ommission Electrotechnique internationale
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COD
P R I X
PRICE
COD
E
Pourpk. wircafa@e on
vigueur
f o r p r i c e , see
currenf
atdogus
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353
m
DIS
- 2 -
890 amend. 1 0 CE1 : 995
Rapport de vote
AVANT-PROPOS
17D(SEC)143
Le prsent amendement a t tabli par le sous-comit 17D: Ensembles
dappareillage basse tension, du comit dtudes 17 de la
CEI:
Appa-
reil ag
e.
17Df148IRVD
Le texte de cet amendement est issu des documents suivants:
Le rapport de vote indiqu dans le tableau
mation sur le vote ayant abouti
lapprobation
ci-dessus donne toute infor-
de cet amendement.
INTRODUCTION
Les articles
de
cet amendement compltent,
articles correspondants du rapport technique
modifient ou remplacent les
890 de la
CE1
- l redition
(1 987): Mthode de dtermination par extrapolation des chauffem ents pour
les ensembles d appareil lage
basse tension drivs de srie
EDS).
Lorsquil ny a pas darticle ou de paragraphe correspondant dans le prsent
amendement, larticle ou le paragraphe de la CE1 890: 1987 et de son
corrigendum de mars 1988 sappliquent sans modification.
Page 8
5.1
Informations ncessaires
Ajouter un nouveau tiret:
- puissance dissipe effective P,) par
les
conducteurs selon lannexe
B.
Supprimer la dernire phrase de la note.
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4844893 0577682 2 T
890
Amend. 1 O IEC:
1995
- 3 -
FOREWORD
This amendment has been prepared by sub-committee 17D: Low-voltage
switchgear and controlgear assemblies, of IEC technical committee 17:
Switchgear and controlgear.
The text
of
this amendment is based on the following documents:
DIS I
R e p o r t o n vo t i n g
I
Full information on the voting for the approval
of
this amendment can be
found in the report on voting indicated in the above table.
INTRODUCTION
The clauses of this amendment supplement, modify or replace the corres-
ponding clauses in the technical report IEC
890 -
1st edition 1987 ) :
A
method of temperature-rise assessment by extrapolation
for
partially type-
tested assemblies PTTA)
of
low-voltage switchgear and controlgear.
Where there is no corresponding clause or subclause in this amendment,
the clause or subclause
of
IEC 890:
1987
and its corrigendum of March
1988 apply without modifications.
Page 9
5.1 Necessary in ormation
Add a new indent:
- Effective power losses P,) of conductors according to annex B.
Delete the last sentence of the note.
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4-
890
Amend.I CEI:1995
Page
49
Ajouter, aprs l'annexe A, la nouvelle annexe
B
comme suit:
Annexe B
.
Courant de fonct ionnement et puissances dissipes par les conducteurs
Les puissances dissipes donnes dans les tableaux B.1, B.2 et B.3 sont fondes
sur:
-
la temprature maximale permise du conducteur
la temprature de l'air autour de conducteur
l'intrieur de l'enveloppe
- le courant de fonctionnement
Les conducteurs montrs dans les tableaux
B.1
et
B.3
sont de plus bass sur les
sections donnes dans la CE1
947-1
"Rgles gnrales" pour les conducteurs en
cuivre.
Pour une charge de conducteur plus faible, l'quation suivante peut tre utilise:
P
= puissances dissipes en watts par mtre (W/m)
i
= courant du conducteur (charge)
In
= courant de fontionnement
Pn = pertes effectives In
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4 8 4 4 8 9 3
0 5 7 9 b 8 4
Ob2
9
890 Amend.
1O
IEC:1995 -5-
Page49
Add, after annex A, the new annex B as follows:
,
Annex
B
Operating current and pow er losses of c onduc tors
The power losses given in tables
B.1, B.2
and B.3 are based on:
- maximum permissible conductor temperature
-
operating current
-
air temperature inside the enclosure around the conductor
The conductors shown in tables
B.l
and
8.3
are additionally based on
cross-
sections which are given in IEC
947-1
"General rules" for Cu-conductors.
At a lower conductor loading the following equation may be used:
P = power losses in watts per metre (W/m)
I
= conductor current (loading)
In
= operating current
Pn
=
power losses at
In
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890
Amend. 1
O
CEI:I
9956-
A i Wim
12 j 2.1
Tableau B.1:
Courant de fonctionnement et puissances dissipes par
les
conducteurs isols
A
i Wim A
f Wim A
f Wlm
8 f
0,9 12
f
2,l 8 i 0,9
-
1
Cross-
cectior
(Cu)
-
-
2
m
1,s
295
4
6
10
16
25
35
50
70
95
120
150
185
240
300
-
25
i
3,4.
32 f 3,7
2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 1 10 11 12 I 13
Temprature maximale permise du conducteur 70 C
18 i 1,8 25 3,4 20 2.2
23
i
1,9 32
i
3,7 25
i
2,3
TemDrature de
48 i 4,8
64 f 5,6
85
i
6,3
104 7,5
35C
5 5 C
31
2,O
50
5,2
32
f
2,l
42
2,4
65
i 5,8
50 3,4
55
i 2,6
85
i
6,3
65
i
3,7
67
f 3,l
115
f
7,9
85 f 5,O
12 i 2,l : 0,9
130
i
7,9
161
i
8,4
I
11
17
I
2,5
i 1,l
22 : 2,6 14 1,l
28
i
2,8 18
.
1,2
85
i
3,4
150
10,s
115 i 6,2
105
3,6
175
i 9,9
149 i 7,2
'air autour des conducteurs I'ir
192 i 8,7
226 i 9,6
275 11,7
295 10,9
c
C
Q)
c
c
O
C
6
W
c
3
5
P
E
s
125
f 3,7
225
11,9
175 i 7,2
147
f 4,l
250
i 11,7
210 f 8,3
167
i 4,3
275
f
11,7
239 i
8,8
191
i
4,6
350 f
15,4
273
i
9.4
rieur de l'enveloppe
Diam.
0,12
2,6
i 1.2 1,7 f 0,5 0,4
0.14
2,9 1,3
1,9 0,6
0,20 3.2
i 1,l
2,l i 0,5 -
0.30 4,4
i
1,4 2,9 i 0,6 0,6
0,34 4,7
i
1,4 3,l 0,6 0,6
0150 6,4 f 1,8 4,2 f. 0.8 0,8
0.56 i 1,6
f
0.7
0.75 8,2
i
1.9 5,4
t
0.8
1,0
1,OO 9,3
f
1,8 6,l
i 0,8
-
-
0,22 3,6 i 1,3 2,3 i 0.5 0,5
35C I 55C I 35C
i '
55C
l'quation suivante peut tre utilise:
I
P
=
PJ-y
I"
P
=
puissances dissipes en Wim
I
= courant du conducteur (charge)
I, = courant de fontionnement
P, =
pertes effectives
I,
G
v)
Q)
9
Q
.-
.-:
8
.-:
U
v)
c
o
3
a
c
c
E
Q)
C
c
O
c
Q,
U
a
P
e
a
K
i
Qi
c
C
O
o
c
Q)
U
C
3
.-
P
E
o
20
i
3,5 12
i
1,3 20
i 3,5
I 12
i
1,3
347
i 12,O
I
225
i 5 , O
I 400
f 15,9
I 322
i
10,3
400
i
13.2 260
i
5.6
I
460
i
17.5 371
i
11.4
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890
Amend.1
O
IEC:l995 -7-
55 C 35 C 55 C
Table B.1:
Operating current and power losses of insulated conductors
35
C
-
1
:rocs-
iection
(Cu)
-
-
195
2.5
4
6
10
16
25
35
50
70
95
120
150
185
240
300
-
-
-
A
f Wlrn
8 f 0,9
11 f 1,l
.2 I 3 1 4 1 5 1 6 1 7 1 8 1 9 1 10 I 11 I 12 I 13
Maximum permisible conductor temperature 70
C
I
A Wlrn A i Wlm A f
Wim
20 3,5 12 i 1,3
20 f 3.5
12 f 2,l 8
f
0,9 12 f 2,l
35 "C
e :
o ' i g
e r , ;
v)
.- i o
Z O j Q I
i 6
A Wlm
12 f 2,l
17 i 2,5
22
i
2,6
28 i 2,8
38
i
3,O
52 3,7
c : L
O f P
14 f 1,l
18
i
1,2
25
3,4
18
1,8
25 i 3,4
32
f
3,7
23
1,9
32 3,7
c
c
al
o
er,
c
5
.-
E
QI
Q
O
34 i 1,6
f i
3
8
3
v)
QI
O
-
O
Q
64
5,6
42
i 2,4
65
i
5,8
85
i 6,3
55
f 2,6
85 i 6,3
c
QI
o
er,
c
5
-
e
a
Q
O
104
7,5
130 i 7,9
161 f 8,4
192 f 8,7
226
f
9,6
275 f 11,7
295
f
10,9
6
v)
3
O
-
8
3
O
P
67
i 3,l
115 i 7,9
85
3,4 150
10,5
105
i
3.6
175 i
9,9
125
3,7
225
i
11,9
147
i 4,l
250 i 11,7
167 i
4,3
275
i
11,7
191
i 4,6
350 i
15,4
c
Q)
o
er,
c
5
e
-
QI
Q
O
347
i
12,O
400 f 13,2
n
(v
v)
3
O
Q>
O
P
-
L
3
225
i 5,O
400 i 15,9
260
'i 5,6
460 17,5
Diam.
0,12 2,6
i
1,2 1,7 i 0,s 0,4
0,14 2,9
i 1,3 1,9
f 0,6 -
0,20 3,2
i
1,l 2,l
0,s -
0,22
3,6 i 1,3
2,3
i
0,5
0 3
0,30 4,4
1,4
2,9
i 0,6 0,6
following equation may be used:
I
P
=
P,(-)*
I n
P
= power losses in Wlm
25 1,3 48
i
4,8 31 2,O
50
5,2
0,34
0,56
0.75
1,00
4,7 i 1,4 3,l
i
0,6 0,6
I =
conductor current (loading)
6,4
'i 0,8 0,8 I,, = operating current
i 0,7
1,6
- P, =
power losses at
I
,2 :
i
1,8
8,2 i 1,9 5,4 i
0,8
1,0
9.3
i 1.8
6,l
f
0,8
55 "C
c
c :
: f i
e r , i v)
.-
i o
8
L m
z i g
g i s
c i
0 : O
O f P
A f Wlrn
8
f
0,9
12 1,3
25 i 2,3
32
i
2,l
50 i 3,4
65 i 3,7
85
5,O
115 i 6,2
749
i
7,2
175
f
7,2
210
i
8,3
239
i
8,8
273 9,4
322 'i 10,3
371
i
11.4
20
i
2.2
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Amend.
1
O
IEC:
1995
-9-
f
a
a
u
C
C
C
c
r
C
6
C
1,25 m2.
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1
0.9
*
*-
*-
0.8
ol
C
O
o
p
2 0 7
O
o
C
W
-
0.6
0.5
0.4
0.3
0.2
0.1
O
O
1
2 3
4
5
6
7
8
9 10
11 12
Effective cooling surface A, (m2)
394187
FIG. .
- Enclosure constant k for enclosures without ventilation openings, with an effective
cooling surface
A ,
> 1.25mz.
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890 O IEC 1987
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II Il II
-
emperature distribution factor c
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I E C 890 8 7
4 8 4 4 8 7 1 0 0 8 8 9 7 8 I
-
6 - 890 O CE1 1987
Section des orifices dentre dair
) (crn2)
m
*f
La
ectio n des orifice s de sortie dair sera au moin s
1,1
foiscelle d es or ifices dentre dair.
396/87
FIG.^.
-
Constante d enveloppe
k
pour enveloppes avec orifices de ventilation et avec une
surface effective de refroidissem entA ,
>
1,25 m2.
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-
890 O IEC 1987
-
7
-
t
c
K
o
v)
C
O
o
c
Cross-section of air inlet openings '1 (crn2)- '14
')The cross-sectionofthe corresponding air outlet openin gs should be at least 1.1 times that
of
the air inlet openin gs.
396187
FIG.
.
-
Enclosure constant k for enclosures with ventilation ope ning s and a n effective cooling
surface A,
>
1.25 m2.
_
I E C
8 7 0
8 7 W
4 8 4 4 8 9 3 0 0 8 8 9 7 9 3 ~
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- 890
O
CE1 1987
al
U
Facteur
hauteurlbase
P
2.2
2 I
2
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
O 100
200 300 400
500 600 700
Section d es orif ices dentre dair
)
(cm)
397187
1)
La ection des orifices de sortie dair sera au m oins
1,l
fois celle des orifices dentre dair.
2)
Facteur haute udba se, voir paragraphe
5.2.3.
FIG. .
-
Facteur d e rpartition de temprature
c
pour env eloppes a vec orifices de ventilation et
une surface effective de refroidissementA,
>1,25
m2.
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Heightlbase
factor
P'
10
2.2
t
2.1
o 2
8
.+ 1.9
e
1.8
2
1.7
?
1.6
.w
o
(o
c
O
3
.-
+
+
i-
1.5
1.4
1.3
1.2
1.1
1
O
100
200
300
400 5 0 0 600 700
Cross-section
of
air inlet openings '1
(crn2)
')The cross-sectionof the corresponding air outlet open ings should be at least 1 .1 times that of the air inlet opening s.
2) Height/base factor, see Sub-clause
5.2.3.
FIG. . - Temperature distribution factor c for enclosures with ventilation openings and an
effective cooling surfaceA,
>
1.25 m2.
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-IC
a,
Q
Q
O
C
a,
a,
i
(o
v)
c
-
J
B
i
+ I E C 8 7 0
8 7 W
4 8 4 4 8 9 3 0 0 8 8 7 8 2
3
- 30 - 890 O CE1 1987
5
4
3
2.5
2
1.5
1
0.8
0.7
0.6
0.5
0.05
0.07
0.1 0,15 0.2 0.3
0.4
0.5 0.7 1 1.3
Surface effective de refroidissement A, (m2)-
398/87
FIG.^.
- Constante denveloppe
k
pour enveloppes sans orifices de ventilation et avec une
surface effective de refroidissementA , G 1,25 m2.
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I E C
870
87 W 4844873 0088983
5
U
~~ ~~ ~~~
890 O I E C
1987
- 1 -
0 05
0.07
0.1
0.15 0.2 0.3
0.4
0.5 0.7 1 1.3
Effective cooling surface A, (m2)
398/87
FIG.. - Enclosure constant k for enclosures without ventilation open ings
and
with an effective
cooling surface
A ,
U
c
O
.-
c
-
o
Q
al
U
3
al
O
L
L
c
2
FIG. . - Facteur de rpartition d e tem prature c pour enveloppes sans orifices de ventilation et
avec une surface effective de refroidissement A , a
1,25
m2.
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1.25
9
c,
c
o
m
c
O
-J
Lc
.-
+
o
I
.- 1.20
U
3
al
g
e
io
.w
2
1.15
1.10
1.05
1
O 0.5
1
1.5 2 2.5
g (see
Sub-clause 5.2.3)
-
99/87
FIG. . -
Temperature distribution factor
c
for enclosures without ventilation openings and with
an effective cooling surface
A , < 1.25 mz.
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-
4-
applicables
pour la dtermination- largeur mm
de rchauffement profondeur mm
890
O C E 1
1987
.-
Orifices de ventilation: oui lnon
Nombre de sparations horizontales:
Calcul de l'chauffement de l'air l'intrieur d'enveloppes
Client/Installation
Dimensions
m x m
2
Partie suprieure
Faade .
Type d'enveloppe
A, X
b
Facteur (colonne 3) x
de surface b (colonne 4)
suivant
tableau
III
m2 m2
3
4 5
Ao
IDimensions hauteur mm I Type d'installation:
Suprieure 1,25 m2
Infrieure ou gale
1,25
mz
Arrire
I
Ct gauche
~~ ~
Ct droit
A, = Z ( A , x b) = Total
).- (voir paragraphe
5.2.3)
I
I =I =
Orifices d'entre d'air um2
Constante d'enveloppe k
Facteur pour sparations horizontales d
Puissance dissipe effectiveP W
Facteur de rpartition de temprature c
At1.n
= c
* Atn.5
K
Courbe caractristique:
3
Echauffement d e l 'air l 'intrieur
de l 'enveloppe Ar
400/87
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890 O IEC 1987 -
5 -
Calculation of temperature rise of air inside enclosures
Customer/plant
Type of enclosure
~ ~
Relevant height mm Type of installation:
dimensions for
temperature rise width mm Ventilation openings: yesho
depth mm Number of horizontal partitions:
:y
according to (Column 4)
Dimensions
TableII 1
m2
2
m x m
5
I - 4 III
I 1 I
Front
Left-hand side
Right-hand side
A ,
=
,Y
( A , x
b)
=
Total
I
With an effective cooling surface A,
Exceeding 1.25 mz Not exceeding 1.25 m2
h1.35
Ab
=
see Sub-clause5.2.3)
g =
I see Sub-clause5.2.3)
I
Air inlet openings cm2 I
Enclosure constant k
Factor for horizontal partitions
d
Effective power loss
P W
p x = p . . .
Ato., = k
* d
* P x
K
Temperaturedistribution factor c
Characteristic curve:
2
8
1.0
-
o
C
a>
0.75
t
Tempe rature rise
of
air inside
enclosure
At 400/87
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I E C
8 9 0
87
=
4 8 4 4 8 9 1 0 0 8 8 9 8 8
4
- 36- 890 0 CE1 1987
ANNEXE
A
EXEMPLES CHIFFRS DE DTERMINATION DE LCHAUFFEMENT
DE LAIR LINTRIEUR DUNE ENVELOPPE
Exemple
I----c
I
I
I
I
I
I
I
I
I
I
,h
---
-
-
-
Enveloppe spare dtache sur tous les cts, sans
orifices de ventilation et sans sparations internes
horizontales.
Puissance dissipe effective de lquipement
install dans lenveloppe:
P
= 300 W
3
00
Dimensions en millimtres
401/87
Conduite du calcul
(Pour les rubriques voir formulaire, page 40, portant sur lexemple 1.)
-
La dtermination de la surface effective de refroidissement A , se fait selon le paragraphe
5.2.1.
Les surfaces lmentaires sont calcules
partir des dimensions de lenveloppe, les
facteurs de surface b tant obtenus du tableau III.
Le calcul de lchauffement de lair Ato,5 seffectue suivant le paragraphe 5.2.2.
Formule (2) de la colonne 2 du tableau I:
Facteur
k
selon la colonne 7 du tableau I, avec
A,
>1,25 m2 selon la figure 3,
page 22:
Facteur
d
suivant la colonne 8du tableau I, avec
A , >
1,25 m2 selon le tableau I V
-
Ato,5
k
d Px (2)
pour
A, =
6,64 m2: k
=
0,135
pour nombre de sparations horizontales
=
O
:
d
=
1,0
Puissance dissipe effective (telle que spcifie) P = 300 W
Exposant x de la colonne 10 du tableau
I,
avec
A,
> 1,25 m2: x
=
0,804
En reportant ces valeurs dans la formule (2) ci-dessus, on obtient le rsultat suivant:
Ato,5 = k * d Px= 0,135 10 * 3001804
Ato,, = 13,24
K m
13,2
K
.
-
Le calcul de lchauffement de lair
At1,o
seffectue suivant le paragraphe 5.2.3.
Formule (3) de la colonne 3 du tableau I:
Ati,o c Ato,5
(3)
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890 O IEC 1987
-
7
-
APPENDIX A
EXAMPLES FOR THE CALCULATION OF THE TEMPERATURE RISE
OF AIR INSIDE ENCLOSURES
Example 1
I
I
I
I
I
I
I
I
I
I
I
-
zontal partitions.
Effective power loss of equipment installed in the
enclosure:P = 300 W
401/87
Calculation
(For entries see form, page 41, on example 1.)
-
The effective cooling surface A, is determined according to Sub-clause 5.2.1.
The individual surfaces are calculated from the enclosure dimensions, and the surface
factor bis taken from TableIII.
The temperature rise of air Ato.5 is determined according to Sub-clause 5.2.2.
Formula (2) from column 2 of Table
I:
Factor
k
according to column 7 of Table I with A ,
>
1.25 m2, as shown in Figure 3,
page 23:
Factor
d
according to column
8 of
Table
I
with
A,>
1.25 m2, as specified in
Table I V
Ato.5 =
k d - PX
(2)
for&= 6.64m2: k = 0.135
with number of horizontal partitions
=
O
:
d
=
1 O
Effective power loss (as specified) P= 300 W.
Exponent x from column 10 of Table I with A,
>
1.25 m2: x =0.804
With these values entered into the above formula (2), the following result is
obtained:
~
Ato.5
At05 13.24K.J 13.2K
k d PX
0.135 1.0 300*804
- The temperature rise of air At1.0is determined according to Sub-clause 5.2.3.
Formula (3) from column 3 of Table
I:
Ati.0
=
c
Ato.5
(3)
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I E C
890
87
W
989q89L 0088990 2
- 8 - 890
O
CE1 1987
Facteur c selon la colonne 9 du tableau
I,
avec A, >1,25 m2 suivant la figure 4,
page 24:
La courbe
1
de la figure 4 donne:
e =
1,44
En
reportant cette valeur dans la formule
(3), on
obtient le rsultat suivant:
Ati,o
= c A ~ , J
1,44 13,24
=
19,07 K
M
19,l K
-
La dtermination de la courbe caractristique dchauffement pour enveloppe avec
A,> 1,25 m2 seffectue selon le paragraphe 5.2.4.1 (voir figure dans le formulaire de
lexemple 1, page 40).
La vrification de la conception de lquipement se fait selon larticle6.
Ce faisant, il faudra sassurer que lappareillage
lintrieur de lenveloppe peut fonc-
tionner de faon satisfaisante lchauffement calcul et sous le courant assign, compte
tenu de la temprature de lair ambiant (voir article 3, note).
Si tel nest pas le cas, les paramtres devront tre modifis en consquence et le calcul
devra tre repris.
-
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890 O IEC 1987 - 9
-
Factor c according to column 9 of Table I with A,
>
1.25
m2,
as shown in Figure 4,
page 25:
Curve 1 of Figure
4
follows:
With this value entered into formula (3), the following result is obtained:
c = 1.44
Ati.0 =
c
Ato.5
1.44 13.24= 19.07K
19.1K
-
The temperature-rise characteristic curve is determined for enclosures withA, > 1.25 m2,
in accordance with Sub-clause 5.2.4.1 (see figure in the form on example 1, page 41).
-
The evaluation of the design is made in accordance with Clause6.
It
is
to be verified whether the equipment installed in the enclosure is capable of func-
tioning satisfactorily at the specified currents and calculated temperature rises, consid-
ering the ambient air temperature (see Clause3, note).
If this is not so, the parameters will have to be changed and the calculation repeated.
F= \.
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-
0 - 890 O
CE1
1987
Partie suprieure
Faade
Arrire
Ct gauche
Ct droit
I Calcul de l'chauffement de l'air l'intrieur d'enveloppes
I
410 OIS o/
900 4 o, 700
dIO x
212
2,200 a/
9 A i 980
4
o
x 2,2
2 ,2 0 0 49 4 ,960
015X
212
4 400
4 9 0,
9 9 0
015 3 12
A,f
00 41
9
o
990
Ciient/inStaiiation ,Exemple
4
Suprieure
I
,25 m2
Type d'enveloppe
mveloppe
*r&
Infrieure
ou
gale 1,25
mz
2
00 m m
Type d'installation: zur b u /a&&
4 060
m m
Orifices de ventilation:
pdi/non
profondeur
50
a m m Nombre de sparations horizontales:
Dimensions hauteur
applicable
pour la dtermination largeur
de l'chauffement
~
I35
A b
f = (voir paragraphe 5.2.3)
- 2 2
=
S , B O
4,o x
0,s
I I I
m x m
m z
m z
P
2 3 4
5
g
= (voir paragraphe 5.2.3)
-
-
Orifices d'entre d'air cmz
Constante d'enveloppe
k
0
O.
4 3 5
Facteur pour sparations horizontales d
Puissance dissipe effective
P
w
.Il D
306
Courbe caractristique:
40
20 3 0
Echauffernent de
l'air
l 'intrieur
de l 'enveloppe At en
K
412 R?
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890 O I E C 1987
- 4 1
-
Calculation of the temperature rise of air inside enclosures
Customer/piant B a n d e i I
I Type of enclosure
snale e K
t/osu/ie I
Relevant height 2 80 mm Typeofinstallation:
befackd
Qt fi 'Acs
dimensions for
temperature-rise width
/o00
mm Ventilation openings: d / n o
depth 500 mm Number of horizontal partitions:
0
o
c
2
bo
c
O
O
o
>
O
I-
-
< *
*
$
w
A , x
b
Dimensions A O Surface factor
b
(Column 3)
X
according to Table (Column 4)
I I I
b 5 m x m m2 m2
T O 2 1
./ 2 3
4
5
TOP l . o x0 . s 6.50d /*4 O -700
Front
1.0%
2.2
2,200 0.9
I.
986
Rear
l.OxZ.2
2.200
o.
9
1.980
Left-hand side
O - 5 X Z . Z
1.100 o. 9 o. 940
Right-hand side
0.5X2.2
/. IO0 0.9 D .
990
I
6.640
,
= E (A,
X
b) = Total
I
With an effective cooling surface
A, I
Exceeding I .25 m2
Not exceeding I
.25
m2
1.35
A b
f = (see Sub-clause 5.2.3) g = $ (see Sub-clause 5.2.3)
-
5.80
=
-
2.2 *35
-
4.0
x
0 c
Air inlet openings cm2
0
Enclosure constant
k
O. I 3 5
Factor for horizontal partitions
d
Effective power loss
P
W 3 0 0
px
p
. 8 0 0
I.
O
98 . 09
I .44
Ai0.S = k
*
d * Px K /3 .24 e 13.2 K
Temperature distribution factor c
Arl ,o= c . A & K 19.07 e
19.1
K
Characteristic curve:
Temperature rise of air inside
enclosure At
in
K
402 '87
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Exemple 2
En
re1
- 2 - 890 O CE1 1987
ppe pour montage mural avec orifices de ventilation
section des orifices dentre dair
=
1 220 cm2
section des orifices de sortie dair = 1 800 cm2
avec deux sparations horizontales
lintrieur de lenveloppe. Chaque sparation hori-
zontale, par exemple tle perfore, comporte des orifices de ventilation dont la section est
suprieure
50% de la section de lenveloppe.
Puissance dissipe effective lintrieur de lenveloppe
P =
2 200 W.
Orifices de sortie dair
Sparations horizontales
avec orifices de ven tilation,
par exemple tle perfore
Orifices dentre d air
Conduite du
calcul
(Pour les rubriques voir formulaire, page 48, portant sur lexemple 2.)
-
Etant donn une surface de refroidissement de lenveloppe qui est probablement sup-
rieure
11,5 m2 et une largeur de lenveloppe suprieure 1,5 m, lenveloppe totale doit
tre divise, aux fins du calcul et conformment au paragraphe 5.2, en colonnes (enve-
loppes partielles). .Aucune subdivision constructive ntant prvue, lexemple dcrit
prvoit, pour simplifier, une division de lenveloppe en deux colonnes gales (moitis
denveloppe). I1 est admis que les puissances dissipes, et les orifices de ventilation sont
rpartis de faon gale dans
les
moitis denveloppe, de sorte quaux fins du calcul, ils
peuvent tre diviss par deux.
Le
calcul nest effectu que pour une seule moiti denveloppe.
Le
rsultat sapplique
galement lautre moiti.
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I E C
-
890 O IEC 1987
-
3
-
Example
2
Enclosure for wall-mounting with ventilation openings
cross-section of air inlet openings = 1 220 cmz
cross-section of air outlet openings
=
1 800 cmz
with two horizontal partitions inside the enclosure. Each horizontal partition, for example
perforated plate, has ventilation openings, the cross-sectional areas of which exceed 50% of
the enclosure cross-section.
Effective power loss of equipment installed in the enclosureP = 2 200
W.
-_
ir outlet openings
I
I
Horizonta l partitions
wit h ventilation openings,
for example perforated plate
Air inlet openings
C
C
c
403/87
Calculation
(For entries see form on example 2, page 49.)
-
Given an expected cooling surface of the enclosure of more than 11.5 mz and an
enclosure width exceeding 1.5
m,
the entire enclosure is to be divided, for calculation
purposes, into sections (partial enclosures) as indicated in Sub-clause 5.2. To simplify the
procedure, as no structural divisions are available, the entire enclosure is, in this
example, divided into two equal sections (enclosure halves). The power losses and venti-
lation openings are supposed to be evenly distributed in both parts (enclosure halves)
so
that for the calculation they are divided by two.
The calculation is carried out for only one enclosure half, the result being applicable to
the other half.
,
-.
.
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I E C 8 9 0 87 E 4844873 0 0 8 8 9 9 b 3 W
- 4 - 890 O CE1 1987
Informations ncessaires selon le paragraphe 5.1 pour une moiti denveloppe
1
Moiti
denveloppe
C
C
h
h
Envelop pe pour montage mural avec
orifices dentre dair
-
--220 -
10 cm2
2
Ave c orifices de sortie dair
-
--oo
-
900
cm2
2
Avec deux sparations horizontales,
par exem ple tle perfore
Puissance dissipe effective
-
2200- i
ioow
2
Dimensions en millimtres
404187
-
La dtermination de la surface effective de refroidissement par moiti denveloppe se fait
selon le paragraphe 5.2.1.
Les surfaces lmentaires sont calcules partir des dimensions de lenveloppe, le facteur
de surface
b
tant obtenu du tableau III.
Conformment au tableau III, la surface de sparation entre les deux moitis denve-
loppe et rsultant de la division fictive nest pas prise en considration.
Le calcul de lchauffement de lair Ato,5 seffectue suivant le paragraphe 5.2.2.
Formule (2) de la colonne 2 du tableau I
Facteur k selon la colonne 7 du tableau I, avec
A,
> 1,25 m2 selon la figure 5,
page 26
Ato,, = k d
P X
(2)
pour une surface des orifices dentre dair de 6 10 cm2avec
A,
= 7,674 m2:
dans le cas de deux sparations horizontales:
k
= 0,071
Facteur d selon la colonne 8 du tableau I, avec
A,
> 1,25 m2selon le tableau V
Puissance dissipe effective (telle que spcifie)
P =
1 100 W
Exposant x de la colonne 10 du tableau
I,
avec A,
>
1,25 m2:
En reportant ces valeurs dans la formule (2) ci-dessus,on obtient le rsultat suivant:
d
=
1,lO
x
=
0,7 15
Ato,5
Ato,5
=
11,67K.J 11,7K
Le calcul de lchauffement de lair Atl,0 seffectue suivant le paragraphe 5.2.3.
k d P X =
0,071 1,lO 1 1000,715
-
Formule (3) de la colonne 3 du tableau I
Ati,o = c Ato,5
(3)
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890
O
I E C 1987 - 5 -
Necessary information according to Sub-clause 5.1 for one half of the enclosure
l i I
Enclosure
half
Enclosur e for wall-mounting with air
inlet openings
-7
220-
610 cm2
I = 2
I With air outlet opening s
With two horizontal partitions,
for
exam ple perforated plate
Effective power loss
Dimensions in millimetres
404187
-
The effective cooling surface of each enclosure half is determined according to Sub-
clause 5.2.1.
The individual surfaces are calculated from the enclosure dimensions, and the surface
factor bis taken from Table
III.
The dividing surface between the two enclosure halves which has been obtained as a
result of the fictitious division, is not taken into account in accordance with Table
III.
The temperature rise
of
air Ato.5 is determined according to Sub-clause 5.2.2.
Formula (2) from column 2 of Table
I
Factor k according to column 7 of Table I and A,
>
1.25 m2, as shown in Figure 5,
Ato.5 = k d P X
(2)
page 27,
for 610 cm2air inlet openings and
A, =
7.674 m2:
k =
0.071
Factor
d
according to column 8 of Table
I
and
A,
>
1.25 m2
as
specified in Table
V
with two horizontal partitions:
Effective power loss (as specified)
P =
1 100
W
Exponent
x
from column 10 of Table
I
with
A, >
.25 m2:
With these values entered into the above formula (2), the following result is
obtained:
d
=
1.10
x = 0.715
Ato.5
=
k * d P X 0.071
Ato.5 =
11.67
K M
11.7 K
1.10 1 100
0.715
-
The temperature rise of air
At1.o
is determined according to Sub-clause 5.2.3.
Formula
(3)
from column
3
of Table
I
A t i . 0
=
c Ato.5
(3)
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- 6 - 890
O
CE1 1987
Facteur c selon la colonne 9 du tableau
I,
avec
A, >
1,25 m2 suivant la figure 6,
page
28,
hl935 2,21935
=
2,50
--
Ab 1,45 0,8
La figure
6
donne pour une superficie des orifices de ventilation de
610
cm2:
c = 1,87
En reportant ces valeurs dans la formule
(3),
on obtient le rsultat suivant:
Ati ,o=
C.
A to,5= 1,87 1 1 , 6 7 K = 2 1 , 8 2 K ~ 2 1 , 8 K
-
La dtermination de la courbe caractristique dchauffement pour enveloppes avec
A,> 1,25 m2 se fait selon le paragraphe 5.2.4.1 (voir figure dans le formulaire de
lexemple 2, page 48).
La vrification de la conception de lquipement se fait selon larticle6.
Ce faisant, il faudra sassurer que lappareillage
lintrieur de lenveloppe peut fonc-
tionner de faon satisfaisante
lchauffement calcul et sous le courant assign, compte
tenu de la temprature de lair ambiant (voir article 3, note).
Si tel nest pas le cas, les paramtres devront tre modifis en consquence et le calcul
devra tre repris.
-
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890
O
IEC 1987 - 7 -
Factor c according to column 9 of Table I.and A , > 1.25 m2, as shown in Figure 6,
h1.35
2.21.35
=
2.50
=
--
Ab
1.45 0.8
Figure 6 shows that, for 610 cm2air inlet openings:
c
=
1.87
With these values entered into formula
(3),
the following result is obtained:
Ati .o=~*At0.5=.87 11.67K=21.82K~21.8K
-
The temperature-rise characteristic curve for enclosures with A ,
>
1.25 m2 is determined
according to Sub-clause 5.2.4.1 (see figure in the form on example 2, page 49).
-
The evaluation of the design is made in accordance with Clause 6.
It is to be verified whether the equipment installed in the enclosure is capable of func-
tioning satisfactorily at the specified currents and calculated temperature rises, consid-
ering the ambient air temperature (see Clause
3,
note).
If this is not
so,
the parameters will have to be changed and the calculation repeated.
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`,,
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I E C
8 9 0 87
M 4 8 4 4 8 9 1
0 0 8 9 0 0 0
T
Dimensions applicables hauteur 2 66 mm
pour la dtermination
de l'chauffement largeur 4
450
mm
d m ve/dppe profondeur 800 mm
48
-
890
O
CE1 1987
Typed'installation: hfmhge
w
Orifices de ventilation: ou
Nombre de sparations horizontales: 2
m X m
2
Y
%
v>
3
O
m2 m2
3 4 5
% e r
4?
&
-2
,?
5
0
't:
3
Dimensions
Facteur de surface (colonne
3)
X