Using a suitable regulator, ensure that alternate current 10A flows through the
created circuit.
-
measure a voltage drop between “the outside protective-conductor terminal”
and various parts of the cover where danger voltage may occur. Value of this
voltage must not exceed 2.6 V.
All found defects must be removed before putting into operation again!!
3.10. Regular revisions
The source is subject to regular revisions according to ČSN 33 1500, ČSN 05 0630
and ČSN EN 60 974-1.
The revisions are carried out by workers with a corresponding electro-technical
qualification and a report on revision (see ČSN 33 1500) must be issued.
ATTENTION: If the source does not meet some of next given points in safety
respect, it is necessary to put it out of operation immediately.
a) Inspection
Mask off the source after disconnection of the power by unplugging the power
supply. Carry out a visual inspection to see whether the electric parts are not
damaged (selector switches, connectors, terminal box, el. supplies, bushings etc.).
Carry out the control of screw and slip connections, their possible tightening or repair.
Control visually whether the mechanical parts are not released or the safe air
distances and surface ways are not disturbed.
Possible defects must be removed
prior to further use.
b) Control of the guard wire
The guard wire must not be damaged or interrupted. Test the strength of individual
interconnections on the connections and connectors by hand.
Continuity of the guard circuit is checked with the power supply of minimally 10A from
the source PELV and for the period of 1 s. Checking is carried out between clamp PE
and various points, which are components of the guard circuit. The guard circuit is
regarded as a compact if the voltage drop is up to 2.6V at the test current 10A.
c) Insulation resistance
Insulation resistance is measured with the voltage 500V ss. Its value according to EN
60 974-1 must not be lower than:
Input clamps (primary) – output clamps (secondary)
5 Mohm
Input clamps (primary) – frame
2.5 Mohm
Output clamps (secondary) - frame
2.5 Mohm
Control circuit (secondary transformers for power supply
of the control circuit) - frame
2.5 Mohm
d) Open-circuit voltage
Voltage measured on the output clamps of the machine must be in tolerance
±
10% to
the value given on the machine label.
