From UL 1598/CSA C22.2 No. 250.0, Clause 16.15
The supporting device was subjected to a load equal to four times the total mass to be supported under intended operating conditions for a period of 1 hour. The load was applied in the direction of actual loading conditions.
Where more than one support was provided, the load was distributed as follows:
- a) where the parts supported were no more than 25 lbs (11.3 kg), the full load was applied to each support; or
- b) where the parts supported were more than 25 lbs (11.3 kg), the distribution of the load was similar to that encountered in the field.
The results were considered acceptable since there was no deflection or deformation either during or after loading that reduced electrical spacings or compromised safety.
The results were considered unacceptable since:
if a) There was deflection or deformation during or after loading that reduced electrical spacings.
or b) There was deflection or deformation during or after loading that compromised safety.
No general environmental conditions are specified in the Standard or have been identified that could affect the test results or measurements.