INM 5500 Rev 11
13
Figure 5 .3:
Optimum orientation for wall mounted enclosure
DX070
DX170
MTL5500
4.03
1.88
Table 5 .2:
Dissipation constant k
1
for enclosures (°C/watt)
Orientation of the enclosures is also important - the optimum position being on a vertical surface with
the internal DIN-rail horizontal as shown in Figure 5.3. Any other position can reduce the maximum
allowable ambient temperature by up to 5°C.
Examples
Tables 5.3 and 5.4 list likely combinations of MTL5500 modules in the three enclosure types and
indicate the acceptable maximum permitted outside enclosure temperature for these based on
the graph in Figure 5.1. See the specifications included in the datasheets for the power dissipation
figures of individual MTL5500 modules.
Table 5 .3:
Typical mix of MTL5500 modules
Enclosure
Modules installed
Power dissipation of modules
in watts (P)
Maximum outside
enclosure temp . (T
MO
)°C
DX070
2 x M 2 x MTL5544
(2 x 0.72) + (2 x 1.4) = 4.24
42.9
DX170
5 x M 5 x MTL5544
(5 x 0.72) + (5 x 1.4) = 10.6
40.1
Table 5 .4:
Power versus maximum outside enclosure temperature
Enclosure
Number of installed
modules
k
°C/watt
Power dissipation
of modules in watts
(P)
Maximum outside
enclosure temp .
(T
MO
) °C
DX070
4
4.03
4.0
43.9
4
4.03
6.0
35.8
DX170
10
1.88
10.0
41.2
10
1.88
15.0
31.8
5 .1 .2 Storage temperatures
Storage temperatures are safe within the range -40°C to +80°C.
5 .1 .3 Humidity limits
Safe humidity limits are within the range 5 to 95% RH.
5 .1 .4 Extended ambient temperature modules
Modules with the -T suffix are rated for use in an ambient temperature up to 65
°C if suitably certifed.
