TDK-Lambda CSS150 Mode D'emploi page 15

CSS150 Product HANDBOOK
Cooling for unit
The CSS150 products are component power supplies designed for building in. To ensure correct thermal
performance at full load the product should be installed in the end system as below and the operating ambient
must not exceed 50° C. Note: maximum operating temp erature is 70° C, for temperatures >50° C to <70° C,
derate linearly to 50% load.
Installation orientation: For correct thermal performance - PCB horizontal, all 4 fixing holes securely
located, Connectors CN1, CN2 & CN3 uppermost. (Also see earthing point information at the end of this
document)
Equipment Top
Base
EMC Performance: Tested to EN60601-1-2:2001. Final compliance must be checked in the end system.
Installation for optimum EMC performance
Mounting
All equipment should be mounted inside an earthed metal box.
If this is not possible then use an earthed metal plane to mount the power supply and load.
Points A and B (of the uncased unit – see earthing points below) should be connected to earth.
Cables
All cables (both ac input and dc output) should be run as close as possible to the earthed metal box/plane.
AC input cable should be a twisted group laid as flat to the earthed metal box/plane as possible.
All output cables should be routed as far away from input cables as possible.
If the input and output cables must be run close to each other then screen one or other (or ideally both).
The positive and negative supply cables should be twisted together.
All cable run loops should be kept as small as possible (this should be implemented in PCB design also).
Connecting between boxes
If cables must be connected between equipment boxes then at the closest possible point to the port where
the cables exit the 1st enclosure connect 100nF decoupling Y caps (between the output and earth). Note that
these capacitors must be rated at the working voltage. Ideally these capacitors should be between all signal
cables which have to connect between boxes although this may not be practical if fast switching [digital]
signals are involved (if this is the case then smaller value Y capacitors should be used).
Earth star point
Where the ac supply enters the equipment, this should be taken to a 'star point' chassis mounted earth point
(Note compliance with EN60950-1 practices which require the main protective earth to have its own dedicated
spring washer and nut) as close as possible to the IEC inlet. All other earth points should be taken back to
this point only.
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Page 15 of 16 72612 issue 4, 25 September 2015