From complete construction and
testing of sub-stations to convenient pick-up and delivery service for circuit
breakers, GMI has developed specific programs to meet the electrical demands
of the mining industry. GMI's engineering department includes personnel who
were Chief Electrical Engineers at large coal facilities.
GMI has complete testing, maintenance,
start-up, and rebuilding services available for coal mine operations.
Testing & Maintenance Include: Metering, protective relays, motor control
centers, low/medium/high voltage circuit breakers, cables, ground beds, switchgear,
Start-up Services Include: Verifying construction specifications, bill of
materials, circuit schedules are correct, schedule and manage testing of new
equipment and prepare turn-over packages.
Rebuilds Include: Oil circuit breakers, molded case circuit breakers, motor
control centers, transformers, and complete used sub-station construction.
Companies such as American Energy,
Ohio Valley Coal, Rosebud Mining, and CONSOL utilize our services for their
electrical engineering needs.
- Design of low and high voltage
electrical power systems (Sub-Stations).
- Specification developed for
procurement of new electrical equipment.
- Electrical economical evaluations
and cost studies for proposed electrical systems.
- Analysis of troublesome electrical
systems for corrective modifications.
- Electrical load flow studies.
- Provide supervision for new
electrical equipment installations.
- Perform start-up testing of
new electrical equipment.
- Provide electrical co-ordination
studies of electrical systems.
- Provide assistance with start-up
of new systems.
- Installation of high voltage
- Primary injection of power circuit
- Welding receptacles, plugs,
line power MCI switches. (new-repaired)
- Trouble shooting of faulty electrical
systems and equipment.
- Switchgear and Electrical high
- Repairs and rebuilds of electrical
power equipment (circuit breakers).
- Relay calibration. Electrical
ground bed testing.
- Power factor testing & Insulating
- Turns radio testing of all transformers.
- Mechanical and electrical adjustments
to all electrical equipment as per manufacture's specification.
*Suggest contractor by the "INTERNATIONAL BROTHERHOOD OF ELECTRICAL WORKERS."
*Customer references & company personnel resumes available at your request.
*Insurance, sample test sheets, & standard rebuild procedures available.
PROCEDURES FOR OIL CIRCUIT BREAKERS"
- Prior to pickup, GMI will need
documentation on content of PCB contamination. If you do not have this documentation
GMI can provide this service at a quoted price. If oil is PCB contaminated,
owner will be responsible for all disposals, including material and handling
- Upon receipt and prior to disassembly,
the oil circuit breaker will be tested both mechanically and electrically.
Megger, power factor, and micro-ohm resistance tests will be performed and
- Non-PCB oil will be drained
from oil circuit breaker and can be returned to customer for disposal. GMI
will dispose of non-PCB oil at a cost of five cents per gallon.
- The circuit breaker tank will
be removed, inspected, and thoroughly cleaned with approved electrical cleaning
solvent. Special attention will be given to phase barriers, faceplate ports,
faceplate supports, and complete tank liner. The exterior will be sandblasted.
- A complete visual inspection
will be performed for physical damage and cleanliness. Nameplate data will
be compared with plans and specifications. Check all gasket covers and seals
for weather-tight condition.
- All current carrying assemblies
will be removed, completely disassembled, and inspected. All silver plated
parts will be cleaned, polished, and re-plated when necessary.
- All bushing and operating rods
will be removed, cleaned, and inspected. Special attention will be given
to the insulating compound of resin-impregnated paper.
- The operating mechanism will
be removed and completely disassembled to its smallest component. All rollers,
pins sleeves, and bearings will be replaced. All operating mechanism parts
and sub-assemblies, including hardware, shall be re-plated. After plating,
the mechanism will be re-assembled according to original specifications.
- All wiring will be inspected
for fraying; any damaged wires will be replaces with type SIS wires. The
complete wiring harness will be tested for proper insulation resistance.
- All electrical control devices
will be thoroughly cleaned and bench tested for proper operation.
- Prior to assembly, all original
painted parts will be sandblasted (if needed), coated with primer and painted.
- Fill breaker tanks with new
insulation oil and provide customer with oil quality analysis.
- After sub-assemblies are complete,
the entire circuit breaker will be rebuilt according to original manufacturer's
- All final test results will
be documented and a copy will accompany each circuit breaker.
The following tests
and adjustments will be performed:
- Adjust the simultaneous close
- Adjust contact pressure.
- Measure contact resistance.
- Perform minimum pickup voltage
tests on trip and close coils.
- Perform insulation resistance
test on each pole-to-ground and pole-to-pole.
- Perform over potential test
on each pole-to-ground and pole-to-pole.
- Perform Power Factor Testing.
- Record time and velocity measurements