4) Check whether 17 (T0) and 18 (T1) terminals of AIM-M10 in each system are connected with the
two ST terminals of isolation transformer and connected reliably.
5) Check whether the terminals 11 (L1) and 12 (L2) of AIM-M10 in each set of systems are reliably
connected with the two wires of IT system (i.e. output end of secondary side of isolation
transformer).
6) Check whether the 1 (FE) and 2 (KE) terminals of AIM-M10 in each system are connected to the
field equipotential terminal block with wires, and whether the S terminal of the isolation
transformer is also reliably connected with the equipotential terminal block.
7) Check whether terminals 3 (A) and 4 (B) of RS485 communication of AIM-M10 instrument in each
system are connected with terminals a and B of AID series external alarm display instrument in a
hand-in-hand manner, and the positive and negative are correct.
8）If each isolation transformer has a cooling fan, check whether the power control of the cooling
fan is connected to the 7 and 8 terminals of AIM-M10 in the system.
9.2 Common faults and eliminations
Make sure the wirings are correct and power on the system. Then check whether each meter is abnormal,
and whether there is a fault alarm in AIM-M10. For common problems, the causes can be determined
and the faults can be eliminated according to the phenomenon of each instrument and the fault types:
Equipment
name
Fault phenomenon
Possible causes and troubleshooting
AIM-M10
insulation
monitor
LCD display
：
FK disconnection,
and the insulation indicator is
lit.
No.1 and 2 terminals of AIM-M10 are not reliably connected to
the equipotential terminals. Check the wirings and make sure
they are reliably connected.
LCD display
：
TC disconnection
fault, and the overheat
indicator is lit.
No.17 and 18 terminals of AIM-M10 are not reliably connected
to the two ST terminals of the isolation transformer. Check the
wirings and make sure they are reliably connected.
LCD display: insulation fault,
and the insulation indicator is
lit.
At least one of the two lines in the IT system at the secondary
side of the isolation transformer has a grounding fault, after
elimination it can be restored to normal.
The instrument is not lit.
The 220V power supply of AIM-M10 is not connected well. Check
the wirings of No.11 and 12 terminals and make sure they are
reliably connected.
AID series
The instrument is not lit.
The 24V power supply is not connected well. Check the wirings