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8.2.2.
Maintenance program
The table shows the maintenance intervals and the frequency of periodical intervention and routine maintenance tasks. The fol-
lowing rules should also be followed:
- Even circuit-breakers that are little used or remain on or off for long periods should be subject to the maintenance programme.
- For circuit breakers fi tted with SACE PR121 installation of the mechanical operation counter (supplied on request) is recom-
mended; the SACE PR122 and SACE PR123 releases with Vaux enable the number of operations performed by the circuit
breaker in use to be displayed at any moment on the display.
- During operation, inspect the switch from the outside to check for dust, dirt or damage of any kind.
Maintenance operations
First level
Second level
(1) Data referring to standard installation in accordance with product standards. For other applications, consult ABB Sace.
(2) Extreme atmospheric conditions, polluted atmosphere or vibrations may shorten the life of the application. Consult ABB Sace.
(3) Emax LTT for low temperature enviroment application (-40°C ... +70°C)
8.3. First level maintenance operations
8.3.1.
Preliminary operations:
- open the switch and check that the control springs are unloaded
- in the case of a circuit-breaker, work on the circuit breaker after it has been extracted (disconnected) from the fi xed part
WARNING: before working on fi xed switches or switches on fi xed parts, disconnect the supply to the power
circuit and to the auxiliary circuits and earth the terminals in a visible manner both on the supply and on the load
side.
8.3.2.
Checks and general cleaning:
- Check that the apparatus (switching part) is clean, removing dust and any traces of excess oil or grease using dry and clean
rags (possibly using non-corrosive detergent.
- For excessive deposits, a laminated dilutant such as Henkel 273471 or the equivalent can be used.
- Check that the rating plates of the apparatus are in place.
- Clean the rating plates with dry and clean cloths.
- Eliminate any dust, mould, traces of condensation or oxidation also inside the fi xed part of the apparatus if the switch is ex-
tractable.
- Check that there are no foreign bodies in the switch cabinet.
8.3.3.
Switch connections and connections between the switch and the control panel
- Use brushes and dry cloths to remove any dust or dirt (if necessary, use non-corrosive detergent.
- For excessive deposits, a laminated dilutant such as Henkel 273471 or the equivalent can be used.
- Check that there are no traces of overheating on the terminals. This problem is due to discolouring of the contact parts; the
contact parts are normally silver in colour.
- Check that the bolts fi xing the connections to the terminals are tight (M12 - 70Nm).
WARNING: before working on fi xed switches or switches on fi xed parts, disconnect the supply to the power
circuit and to the auxiliary circuits and earth the terminals in a visible manner both on the supply and on the load
side.
- Check that the connecting screws of the cables of the terminal boards are tight (0.7 Nm).
Fig. 32
Model
L6555
Installation in normal environments
One year or 20% mechanical life
or 20% electric life
Three years or 50% mechanical life
or 50% electric life
or after intervention on short circuit
Interval
Installation in dusty environments
and low temperature enviroment
[ (1) = level of measured dust > 1 mg/m³ ]
6 months or 10% mechanical life
or 10% electric life
18 months or 25% mechanical life
or 25% electric life
or after intervention on short circuit
Apparatus
Doc. no.
1SDH000460R0002
( 1)/( 2)
( 3)
Scale
Emax
Page No
20/74
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