L2275
Emax UL
19/132
Doc. N°
Mod.
RH0109002
Apparatus
Scale
Page N°
Fig. 33
8.3.2
General inspection of the power circuit breaker
Item to be inspected
1 Operating mechanism/Electrical accessories
2 Arcing and main contacts
3 Arcing chambers
4 Main circuit - Busbars - Isolating contacts
5 Grounding pliers (only for draw out power circuit
breaker)
6 Grounding connection (only for fixied power circuit
breaker)
7 Auxiliary circuit power supply voltage
8 Operating and control parts
Problem found
– Presence of dust on the internal parts
– Springs deformed or oxidized
– Safety rings out of place, nuts or screws loose
– Wires and straps detached
– Traces of wear
– Incorrect adjustments: distance A (Fig. 33) is less
than 1mm for E1-E2-E3 or less than 0.8 mm for E4-
E6
– Presence of fumes or dusts
– Presence of cracks on the external plastic structure
– Excessive difference in wear between the first and
last arc extinguishing plate
– Remove with compressed air and remove the fumes
and any slag with a brush
– Presence of dust or dirt on the insulating parts
– Safety rings out of place, screws or nuts loose
– Deformation or cracks of the insulating parts
– Isolating contacts oxidized (only for draw out power
circuit breaker)
– Signs of wear or overheating or screws loose on the
connections to the terminals of the power circuit
breaker (only for fixed power circuit breaker)
Presence of oxidation or loose nuts
Presence of oxidation and / orloose nut
Check the power supply voltage of the electrical
accessories of the operating mechanism
The operating tests, which must be carried outas
shown in paragraph 6.1 have shown defects in the
components
Remedy
– Clean with brushes or dry cloths
– Replace damaged springs
– Put the rings back in place and tighten screws and
nuts appropriately
– Replace the straps and connect the detached wires
correctly
– Smooth the contacts with emery cloth
– Adjust according to the paragraph 8.3.3
– Replace the arcing chamber
– Replace the arcing chamber
– Replace the arcing chamber
– Clean with a brush or dry cloths
– Put the rings back in place and tighten screws and
nuts appropriately
– Ask ABB SACE for replacement of the damaged parts
– Remove the shutters and clean with a rough
clothsoaked in a suitable solvent and lubricate
moderately with neutral grease
– Tighten the screws suitably
Clean with a rough cloth soaked in a suitable solvent
and lubricate moderately with neutral grease. Tighten
the nuts fully
Clean with a rough cloth soaked in a suitable solvent,
fully tighten withthe ground connection and coverwith
neutral grease again.
The trip units and locking devices must operate
normally for values between 85% and 110% of the
relative rated voltage
Replace the defective parts or those with defective
operation (if necessary, ask ABB SACE)
Power circuit breaker
E1 - E2 - E3
1
÷
1.9 mm
0.039
÷
0.075 inch
E4 - E6
0.8
÷
1.5 mm
0.031
÷
0.059 inch
A
8.3.3
Checking contact wear
In order to obtain distance A indicated in the table, it is possible to ad
just the position of the shaft and of the operating mechanism comando.
1 ) Open the circuit-breaker
2 ) Remove the arcing chamber
3a) Adjustment of moving contact detachment for E1-E2-E3:
- loosen the screws in pos.1 and the nuts in pos. 3 (FIG 33 a)
- work in a similar way on the screws in pos. 2
- take the bushes of the operating mechanism (pos. 5) to rest on
the shaft, working on the nuts in pos. 4
- tighten the screws in pos.1 and the nuts in pos. 3 and 4
- close the circuit-breaker and check distance A
3b) Adjustment of moving contact detachment for E4-E6:
- loosen the screws in pos.1 and 6, and the nuts in pos. 3 and 8
(FIG 33 a and 33 b)
- work in a similar way on the screws pos. 2
- take the bushes of the operating mechanism (pos. 5) and the
bushes of the intermediate shoulders ( pos. 9) to rest on the
shaft, working on the nuts in pos. 4 and the screws in position 7
- tighten the screws in pos.1 and 6, and the nuts in pos. 3, 4 and 8
- close the circuit-breaker and check distance A
4 ) If the distance is not correct, open the circuit-breaker again and
repeat the operation indicated under point 3a or 3b
5 ) If distance A is correct, open the circuit-breaker again, seal with
a yellow paint and remount the arcing chambers.
