ABB V-Contact VSC Series User Manual

37
7.3. Inspection
– Carry out regular inspections to check that the interruption
devices are in good condition.
– The checks must include a visual inspection to find any
contamination,tracesofcorrosionorelectricaldischarge
phenomena(accordingtowhatisprescribedintable4.
–Whenthereareunusualserviceconditions(including
adverse climatic conditions) and/or in the case of
environmentalpollution(e.g.heavycontaminationoran
atmospherewithaggressiveagents),thefrequencyof
inspections must be increased.
– Visual examination of the main contacts. The contact
areas must be cleaned if there are signs of overheating
(discolouredsurface)(alsoseetheparagraphon“Repairs”).
Ifanyanomalousconditionsarefound,appropriate
maintenancemeasuresmustbetaken(seethe“Servicing”
paragraph).
Fig. 17
VSC 7 VSC 12 / VSC-S
M [mm] 1.5...2 1.3...1.7
TABLE 4
Item to be inspected Interval Operation to be carried out
1 Insulating parts. 1 year or
50,000operations.
Visual inspection of the insulating parts. The insulating parts must be free of any
accumulationofdust,humidity,dirt(clean),cracks,tracesofsurfacedischargesor
damage.
2 Structure.. 1 year or
50,000operations.
Visual inspection of the structure and mechanisms. The components must be free of any
deformation,accumulationofdust,dirtordamage.Thescrews,nutsandboltsmustbe
correctly tightened. Avoid touching the ceramic surface.
3
Interrupter. 1 year or
50,000operations.
Checkthattheinterrupterisfreeofaccumulationofdust,dirt(clean),cracks(replace),
traces of surface discharges or damage.
In case of accidental
impacts.
Carry out a voltage test with the contacts open at 15 kV - 50 Hz for one minute. If there
isadischargeduringthetest,theinterruptermustbereplacedbecausethistypeof
phenomenoncorrespondstodeteriorationinthedegreeofvacuum.Incaseofneed,
contact ABB Service.
4
Interrupter contacts. 1 year or
50,000interruptionsatthe
rated current.
Refer to fig. 17.
The contact material vaporises from the surfaces during each interruption and condenses
elsewhereinsidethevacuuminterrupter.Thisisanormalprocess,andisforeseenbythe
overrun,orbytheweartolerance.
Asthecontactswear,theoverrundistance“M”decreases.
Whendistance“M”,ofanypole,goesbelow0.5mmwiththecontactorintheclosed
position,allthesub-assembliesmustbereplaced.
Use a fork-shaped gauge 0.5 mm thick to carry out this measurement.
Caution! Never attempt to adjust the nuts of the vacuum interrupters for any reason
whatsoever.
Theoverrundistancemustbechecked,butnotadjusted.
5
Auxiliary contacts. 1 year or
50,000operations.
Check correct operation and the signals. Check that there are no burnt or worn contacts
(replace).
6
Auxiliary circuit
conductors.
1 year or
50,000operations.
Check whether any cabling straps are loose or broken and check connection tightness.
Examine all the wire or cable connections to make sure that none of them are loose and
that there is no overheating.
7
Visual inspection of
the isolating contacts
(withdrawablecontactors)
5 years. The isolating contacts must be free of any deformation or erosion.
Lubricate the contact elements with 5RX Moly type grease.
NEPSI.COM - Northeast Power Systems. Inc.

ABB V-Contact VSC Series Specifications

General

Brand	ABB
Model	V-Contact VSC Series
Category	Industrial Electrical
Language	English