Philips PM 5390 - Safety Inspection and Tests after Repair and Maintenance; General Directives; Safety Components; Checking the Protective Earth Connection

SAFETY
INSPECTION
AND
TESTS
AFTER
REPAIR AND MAINTENANCE
IN
THE
PRIMARY CIRCUIT
GENERAL
DIRECTIVES
—
Take care that creepage
distances
and
clearances
have
not been
reduced
—
Before soldering,
wires:
—
should be bent
through the
holes
of solder
tags, or
wrapped round
the
tag in the form of an
open
U,
or,
wiring
ridigity
shall be
maintained by
cable
clamps or cable lacing.
^
Replace ail insulating guards and
-plates.
SAFETY
COMPONENTS
Components
in
the
primary circuit may
only
be
renewed
by
components selected
by
Philips,
see
also
chapter
9.1
.
CHECKING
THE PROTECTIVE EARTH
CONNECTION
The
correct connection
and
condition is
checked
by
visual control
and
by
measuring
the resistance
between
the
protective
-lead connection at
the
plug
and the
cabinet
/fra
me.
The
resistance shall not be
more
than 0.5 r2. During
measurement
the
mains cable should
be
moved.
Resistance variations Indicate
a
defect.
CHECKING
THE INSULATION
RESISTANCE
Measure
the insulation
resistance at
U
=
500 Vdc 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 M^2.
Note;
2
is a minimum requirement at
40^
C
and
95 % relative humidity.
Under normal conditions the
insulation
resistance should be much
higher
(10
to
20 MO).