Philips PM3208 - 8 Safety Inspection and Test After Repair in the Primary Circuit; 8.1 General Directives; 8.2 Safety Components; 8.3 Checking the Protective Earth Connection

8 SAFETY INSPECTION AND TEST AFTER REPAIR IN THE PRIMARY CIRCUIT 8-1
8 SAFETY INSPECTION AND TEST AFTER REPAIR
IN THE PRIMARY CIRCUIT
8.1 GENERAL DIRECTIVES
- Take care that the creepage distances and clearances have not been reduced.
- Before soldering, the wires should be bent through the holes of solder tags, or
wrapped around the tag in the form of an open U, or, wiring rigidity shall be
maintained by cable clamps or cable lacing.
- Replace all insulating guards and -plates.
8.2 SAFETY COMPONENTS
Components in the primary circuit may only be renewed by components selected by
Philips, see also section 7.1.2.
8.3 CHECKING THE PROTECTIVE EARTH CONNECTION
The correct connection and condition is checked by visual checking and by measuring
the resistance between the protective lead connection at the plug and the cabinet/frame.
The resistance shall not be more than 0,1 Q. During measurement the mains cable
should be removed from the mains. Resistance variations indicate a defect.
8.4 CHECKING THE INSULATION RESISTANCE
Measure the insulation resistance at U = 500 V (dc) between the mains connections and
the protective lead connections. For this purpose, set the mains switch to ON. The
insulation resistance shall not be less than 2 MQ.
NOTE: 2MQis a minimum requirement at 40 °C and 95 % relative humidity.
Under normal conditions the insulation resistance should be much higher —
(10...20 MQ). i
8.5 CHECKING THE LEAKAGE CURRENT
The
leakage
current
shall
be
measured
between
each
pole
of
the
mains
supply
in
turn,
and
all
accessible
conductive
parts
connected
together
(including
the
measuring
earth
terminal).
The
leakage
current
is
not
excessive
if
the
measured
currents
from
the
mentioned
parts
do
not
exceed
0,5 mA
(rms).
8.1 GENERAL DIRECTIVES