Repair Operations For Possible Malfunctions - Abb Mns R Manual De Instalación

5.4

Repair Operations for Possible Malfunctions

MALFUNCTION
1. Malfunction of circuit breakers or
apparatus installed in the switchboard
2. Compartment or unit heating
abnormalities
3. Condensation formation
4. Automatic controls do not function
5. Unwanted trip of circuit breakers
6. Humming of the metallic structure
Each maintenance operation must be performed only by qualified personnel,
always observing the safety rules.
POSSIBLE CAUSE
See the related installation,
operation and maintenance
instructions
Ventilation grids and/or ducts
blocked
Connections between busbars,
joints and/or terminals not properly
tightened
Improper setting or malfunction
of the anticondensate heater
thermostat
Malfunction of the anticondensate
heater or of the related power
supply circuit
Component malfunction
• Improper coordination of the
protection
• Overheating caused by loosen
connections or dirty or oxidated
isolating contacts
• Failure caused by the
overcurrent releases
Screws loose of the segregation
plates (if equipped) or of the
external closing panels
REMEDY
See the related installation,
operation and maintenance
instructions
Clean by means of a vacuum
cleaner and check the upper
grids
Check the status of the contact
surface, then tighten according
to the tightening torques
indicated in Appendix A
Set properly the thermostat. If
necessary, replace it
Search the cause; if necessary,
replace the anticondensate
resistance (ask ABB SACE)
Search the possible cause by
referring to the switchboard
operation diagram. If necessary,
ask SACE
• According to system
selective diagrams, check
the correspondence of the
maximum current release
device setting of the relevant
circuit breakers
• Clean with solvent the
isolating contacts both
of fixed parts and circuit
breakers, then lubricate with
vaseline greese
• If the failure is caused by
the overcurrent release,
check first the temperature
inside the circuit breaker
compartment. See also the
circuit breaker instruction
manual
General check of the
segregation plate fixing or
external closing panel
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