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DOC-MN-007-03 VCCM600 User Manual
Vox Power Limited | Unit 2, Red Cow Interchange Estate, Ballymount, Dublin 22, D22 Y8H2, Ireland | T +353 1 4591161 | www.vox-power.com
Specifying the VCCM600 product for convection or forced air cooling
To specify a VCCM600 series product for an end application, the required output power, minimum input line voltage, maximum ambient, mounting orientation
and air flow rate (if applicable) should be determined. Check the requirements against the closest characteristic plot from the tables above to ensure ratings can
be achieved. Be conservative when specifying the product as convection and forced air cooling can be highly dependent on the end application enclosure and
power supply mounting. The estimated performance must be verified in the end application and temperatures may exceed predicted levels. It is also important
to note that ambient temperature refers to the ambient temperature immediately surrounding the PSU. If the PSU is mounted within an enclosure the enclosure
ambient temperature is likely to be higher than the external air ambient temperature.
Evaluating the VCCM600 product in the end application
To ensure the product is operating within its ratings in the end application the following procedure should be performed during the design stage.
1.
Install a thermocouple in position TS1 of the product. (See Mechanical dimensions and mounting for details.) The thermocouple wire should exit on
the top side between slots 2 and 3. The bottom side should be flush for heatsink mounting if necessary. Glue should be used to hold the
thermocouple in place.
2.
Setup the application in worst case conditions, considering Input line voltage, Output power, ambient temperature, airflow and cooling restrictions.
3.
Power the system and monitor the baseplate temperature until it reaches steady state.
4.
Ensure that under worst case conditions, the baseplate temperature cannot exceed the rated temperature as outlined in the power ratings section of
this manual.
If a cover is placed over the primary components, then the following component temperatures must also be measured to ensure they are below the maximum
specified temperatures.
Description
Reference
Maximum allowed temperature
Drawing
Fuse
FS1, FS2
125
°
C
Electrolytic capacitors
C12
105
°
C
Inductors
L1, L2, L3, L5
130
°
C
Other capacitors
C1, C4
110
°
C
If excessive temperatures are measured during this evaluation, then one or more of the following remedies may improve thermal performance.
Increase heatsink size
Increase airflow rate
Improve air intake & outlet
Reduce power requirement
Using the internal temperature sensor to control external application cooling
An internal temperature sensor T
SNS
is available on J3 pin 9 (See page 14 for details). The output voltage of this sensor gives a measurement of the internal
transformer temperature
and can be used to control external cooling systems or to provide a warning of impending over temperature protection.
The internal temperature (T
SNS
) should never exceed 120⁰C (2.74V), however, system reliability will be maximised if the PSU temperature is maintained as low as
possible in any given application.
