HT instruments SIRIUS87 - Manual (Page 76)

SIRIUS 87
EN - 74
Switch situation Point under test Measurement result Judgment on the installation
1
Turn the switch
A, l D and E off
Effect the measurement
on switch A
If R
 R
LIMIT
 OK (end of the test)
If R
 R
LIMIT
Proceed  2
2
Turn the switch
B off
Effect the measurement
on switch A
If R
 R
LIMIT
Proceed  3
If R
 R
LIMIT

The insulation level between A
and B switches is too low, restore
it and effect the measurement
another time.
3
Effect the measurement
on switch B
If R
 R
LIMIT
 OK (end of the test)
If R
 R
LIMIT

The insulation level after B
switch is too low.
Proceed
 4
4
Turn the switch
C off
Effect the measurement
on switch B
If R
 R
LIMIT
Proceed  5
If R
 R
LIMIT

The insulation level between B
and C switches is too low, restore
it and effect the measurement
another time.
5
Effect the measurement
on switch C
If R
 R
LIMIT
 OK (end of the test)
If R
 R
LIMIT

The insulation level after B
switch is too low, restore it and
effect the measurement another
time.
Procedure steps for insulation measurement referred to the installation reported in
NOTE: The switches D and E are those installed near the load having the purpose of
separating it from the installation. In case the above said RCDs do not exist, or
they are monophase, it is necessary to disconnect the users from the installation
before effecting the insulation resistance test.
NOTE: If the circuit is quite large the conductors running side by side make up a capacity
which is to be charged by the instrument in order to carry out a correct
measurement; in this case it is recommended to keep the
START/STOP key
pressed (in case a test is effected under manual mode) until the result gets stable.
ATTENTION: When you effect measurements among active conductors it is essential to
disconnect all the users (alarm lamps, intercom transformers, boilers etc)
otherwise the instrument will measure their resistance instead of the
installation insulation. Moreover any insulation resistance test among
active conductors could damage them.
The indication
"> 999M " or “o.r.” (out of range) warns that the insulation resistance
measured by the instrument is higher than the maximum resistance limit (see technical
specifications); this result is obviously far higher than the minimum limits of the above
table therefore if during a test this symbol is displayed the insulation of that point is to be
considered in compliance with standards.