Maintenance - Icar MICROmatic HP10 Manuel D'installation Et D'opération

8. MAINTENANCE

Routine maintenance
Periodic checks should be carried out on the following items, by filling the sheet of the maintenance logbook
attached at the end of this manual:
- Current drawn by the single steps, in order to keep the operating conditions of the system always under
control.
- Electronic units (reactive power controller and module MCP4) so as to check their efficiency.
- Fuses of the control circuits.
- Fuses of the capacitor banks (provided with disconnect switch).
- Check the operating temperature condition, therefore efficiency of the exhaust electric fan. It is essential to
carry out the 3 monthly maintenance of the suction filters in order to ensure correct recirculation of the air
inside the system and to avoid build up of dust inside. In fact, dust, together with humidity, could become a
hazardous factor of surface conductivity on the insulating materials. The maintenance operation and cleaning
should be performed by qualified personnel.
- Check efficiency of the contactors by periodically inspecting the terminals for tight connection.
- Check for presence of capacitors with the overpressure device tripped (this can easily be recognized by
expansion in the top zone of the casing). Restore them immediately by installing new capacitors (it is
necessary to replace such units in order not to impair the efficiency of the entire system).
- We recommend keeping a minimum quantity of spare components always on hand in order to act quickly on
the system. Likewise this operation should be carried out by qualified personnel.
Particularly important is the testing of the capacitors on units of the FD,and FH series, where it is essential to
check whether the filter tuning frequency has not altered over a period of time; although the components used
are highly reliable, it could be possible for a capacitor nearing the end of its working life, to cause tripping of
relative overpressure device.
The consequent drop in capacity could cause a variation in the tuning frequency of the filter thus producing
hazardous overloads.
In order to ensure long-term protection against such possible phenomena it is advisable to check the amount of
current drawn by each step during the initial installation phase, and after the first month of operation, then four
times a year; obvious differences between subsequent measurements or any unbalance between the three
phases are symptoms of a no longer reliable operation and this could require special maintenance.
Special maintenance
Carry out accurate maintenance work each time the unit requires it because it is subject to unusual and
unexpected phenomena.
A more accurate maintenance schedule should be drawn up taking into account the particular operating
conditions. For example, a highly polluted environment (dust-laden or salty) could require more frequent
cleaning of the filters.
Replacement of components
In power factor correction systems, as in all electric-electronic equipment, it is not sufficient to replace the
individual components; rather it is necessary to understand the causes determining the inefficiency.
A) Replacement of fuses.
Before replacing a fuse on the power circuit or the control circuits, eliminate the cause determining the event.
Replace them with a type equivalent to the original ones.
B) Replacement of the contactors.
The contactors have a working life equal to 100,000 cycles, therefore they should be replaced after such
period has elapsed. When it is not possible to assess the number of cycles reached (N.B. there is a software
function for reading such data in the new controllers) it is necessary, where possible, to inspect the contacts
and to take the necessary steps accordingly.
Replace them with a type equivalent to the original ones.
C) Replacement of the capacitors.
Replace the capacitors with the same type of components, unless otherwise instructed by the ICAR
Technical Service Department, after one of the following faults have occurred:
- Loss of insulating liquid
- Overpressure device tripped (can be seen by the obvious deformation of the capacitor).
- Current drawn by the capacitor less than 10% of rated current at the rated voltage (only in the case of
capacitor banks provided with blocking inductors).
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