ANSI UL 458 - Switch Position; Component Malfunction; Rectifier and Capacitor Short-Circuit Test; Vibration Test

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47.3 Switch position
47.3.1 A converter or inverter provided with a manual battery-to-converter transfer switch and a
battery-charging circuit is to be operated as described in the input test except with the transfer switch in
the battery position.
47.3.1 effective April 13, 1993
47.4 Component malfunction
47.4.1 Individual electronic components of a converter or inverter are to be, in turn, open-circuited and
short-circuited.
47.4.1 revised January 27, 1995
47.4.2 The tests specified in 47.4.1 are to be conducted separately. Short circuits are to be applied
between only two terminals of a multiterminal device at one time. The abnormal condition is to be
introduced while the equipment is operating under intended conditions. This may be accomplished by
jumper leads and remote switches with consideration given to the effect these devices may have on the
test.
47.4.2 effective April 13, 1993
47.5 Rectifier and capacitor short-circuit test
47.5.1 If a rectifier and an electrolytic capacitor are connected across a primary supply circuit in series
with a resistance of less than 300 ohms, a risk of fire or electric shock shall not result with the capacitor
or the rectifier being short-circuited.
Exception: If analysis of the test results and circuit indicates that the result obtained is the only one likely
to occur, the test need be conducted only once.
47.5.1 effective April 13, 1993
47.5.2 The supply circuit of a power converter is to be protected by a branch-circuit overcurrent-protective
device in accordance with 48.3.2.
47.5.2 effective April 13, 1993
47.6 Vibration test
47.6.1 After the converter or inverter is subjected to the vibration test described in 47.6.2:
a) The converter or inverter shall comply with the requirement in 47.1.1,
b) There shall be no loosening of parts, and
c) The converter or inverter shall operate normally.
47.6.1 effective April 13, 1993
47.6.2 The vibration test shall consist of vibration for 1 hour at a frequency of 12.5 cycles per second with
a displacement of 1/4 inch (6.4 mm) in a vertical plane. The converter or inverter is to be mounted as
intended in accordance with the manufacturer’s instruction manual during the test.
47.6.2 revised October 15, 2004
OCTOBER 15, 2004 UL 458 61