Energy Guide

Page 47 of 104 Report No.: HK2107050725-SR
UL 507
Clause Requirement + Test Result - Remark Verdict
TRF No. UL507A
a)The input to the source of that secondary is to be
connected as intended;
b)The maximum open circuit voltage potential
available to the secondary circuit under
consideration is to be measured across the source
of that secondary; and
c)The current available to the secondary circuit
under consideration is to be measured by
connecting a variable resistive load across the
source of that secondary and then varying the load
until an available current of 8 amperes is obtained
for 1 minute of operation. When an available
current of 8 amperes is not obtained under any
condition of loading, up to and including a short
circuit, then the test is to be discontinued for that
circuit.
N/A
31.4.3 For a transformer, only one secondary circuit of a
multiple secondary transformer is to be tested at a
time and all other secondaries not under test are to
be loaded as intended. The voltage and current
measurements are to be made directly across the
secondary output terminals of the transformer.
When a tapped transformer winding is used to
supply a full-wave rectifier, the measurements are
to be made from either end of the winding to the
tap. When the transformer is used as part of a
switching-type power supply, the voltage and
current measurements are to be made after the
transformer secondary winding rectification means.
N/A
31.4.4 A secondary fuse or other such secondary circuit
protective device used to limit the available current
in accordance with 31.4.1, shall be rated at not
more than the values specified in Table 31.1. See
N/A
31.4.5 The secondary circuit protective device referenced
in 31.4.4 is not prohibited from also being provided
in the primary circuit. When provided in the primary
circuit, there are no restrictions on the current
rating of the protective device as long as it limits
the available secondary current in accordance with
Table 31.1.
N/A