ABB MNS-MCC, Инструкция по установке, эксплуатации и обслуживанию

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35 I N S TA L L AT I O N , O P ER AT I O N S A N D M A I N T EN A N C E M A N UA L
Commissioning
Physical equipment check
Check all of the following items related to the
installation and site before energizing the MCC:
• Are the MCC shipping splits connected properly
and the lineup firmly attached to the foundation
or false floor?
• Are shipping-split bus splices at all bars
tightened to the proper torque? Refer to the
Torque Table in this manual.
• Are all of the factory-installed splice connections
still at the proper torque as indicated by the
alignment of the painted marks on the bolts?
• Are all barriers, plates, doors and locks in place?
• Are the bottom plates, if used, properly installed?
• Are all tools, dirt/debris, shipping/packing
materials and other foreign objects removed
from inside the MCC?
• Is the equipment properly grounded?
• Is the phase sequence marking correct?
• Have all withdrawable units been inserted and
removed to test interlock?
Prepare to energize the MCC
Always use properly insulated tools and
instruments during commissioning. Short circuit
current in low-voltage MCCs are typically very high.
Depending on trip settings, high short circuits with
long durations can occur.
Follow all codes and regulations related to
servicing and installing electrical equipment.
Failure to follow these instructions can result in
short circuit and electrical arcing.
Check all of the following items related to the
electrical connections and systems before
energizing the MCC:
• Ensure the electrical characteristics of the MCC
(e.g. rated voltage, short circuit current rating,
grounding system, etc.) are compatible with the
site conditions.
• Inspect the withdrawable units, following the
instructions in the Inspecting Units section of
this manual.
• Inspect the unit contacts, following the
instructions in the Inspecting Units section of
this manual.
• Using the proper tool for each connection, verify
the tightness of all control and power terminals
within the units.
• Insert all necessary fuses in the main and auxiliary
circuits, verifying that they match the apparatus
list and the circuit diagram.
• Set the main circuit protective device feeding the
MCC to its lowest value.
• Set the units’ protective devices to the specified
values.
• If present, verify that current transformers are
properly connected or short-circuited.
• If an external control voltage is present, verify
that it is OFF.
• Close and latch all doors.
• Test electrical insulation resistance using a
megger with a potential of 500-1000 V. Conduct
the test phase-to-phase, phase-to-ground, and
when applicable, phase-to-neutral.
Conduct the test with all unit disconnects in the
OFF position. If the MCC is equipped with potential
transformers (for metering, etc.) remove the
primary fuses prior to performing the test. Typical
insulation resistance values should be ≥100 MΩ.
NOTE: When conducting an electrical insulation
resistance test, isolate equipment sensitive to high
test voltages, such as meters, solid state devices,
motor winding heaters and capacitor units.
Following successful completion of the test,
reconnect all relays, operating voltages, circuits
and fuses.
Energize the MCC
Use appropriate personal protective equipment
(PPE) and follow safe electrical rules and work
practices for electrical installations as described in
standard NFPA 70E, and any other local safety rules
and practices.
After completing all of the previous steps related to
installation and commissioning, energize the MCC
following these steps:
• Apply power on the main incoming.
• Verify that the incoming phase sequence is
correct.
• Switch on the main disconnect.
• Check the phase sequence of each unit
• If existing, switch on any external power sources.
Final testing
Check that all instrumentation is working properly
and the readings are within specifications or
reasonable levels.
Check that all instantaneous protections that were
turned down during previous testing are reset to
their operating positions.