by Mark Bowling, Level II Thermographer, IRISS Inc.

Overview

Connected Power Phosphate Services LLC of Lakeland, Florida provides
maintenance for the mining sector in Florida and Georgia. One of their major
customers, a phosphate mining operation with multiple sites around the United
States was experiencing difficulties with their high-power electrical equipment.
Being a preferred channel partner of IRISS, they contacted us for assistance.

On the mining site, the phosphate is mined by a dragline and the phosphate-rich
sediment is then mixed with water to form a slurry. That slurry is pumped via
1,500 horsepower motor/pump combinations to the processing plant so that the
phosphate nodules can be separated from the rest of the sediment and rock. Each
site has multiple sled-mounted motors and motor controllers for pumping the slurry
material. The motor/pump is typically mounted on one sled while the motor
controller speed drive is mounted on a second sled. To complicate matters from a
safety perspective, all of this equipment operates at 4,160 volts.

For Condition-Based Maintenance (CBM) purposes, the desire is to perform an
infrared inspection on both the motor and the motor controller sleds under load. For
safety, this occurs with all panels and doors closed and in a guarded condition. CAPENV-
12 large format IR windows were mounted on the starter housing to allow
inspection of the main cable leads and also the motor end housing for inspection of
the brushes.

In addition, CAP-ENV-24 windows were mounted on the incoming cable
termination chamber of the motor skid. This allowed inspection of the main
cable terminations and the large medium voltage starter capacitor terminals.

In addition to the six (6) IR windows fitted to the motor/pump skid, an additional five
(5) IR windows were fitted to the motor controller speed drive skid. These units allow
for IR inspection of critical electrical joints and a means for visual confirmation of
disconnection from the short circuit protection device, a Mining Safety and Health
Administration (MSHA) requirement.

Ralph Durance, President of Connected Power Phosphate Services, explained that
the end customer was pleased with the outcome of this project. “The mine was
so happy with the first sleds, that they quickly agreed to roll this out on a wider
basis. We have now completed fourteen sets of sleds,” said Ralph. He added,
“IRISS has been great to work with making design modifications to install these
units — especially when mounting to a one-quarter inch steel plate on the motor
housing. The mine tried round crystal IR windows in the past and those didn’t
stand up to the harsh conditions. Some failed within months of installation. We
have had zero issues with the IRISS products since we started this program two
years ago.”

The CAP-ENV Series of large format rectangular IR windows used on these
projects feature:

• Patented reinforced polymer optic system
• NEMA 6 / IP67 protection rating
• Construction from stainless steel for harsh mining environments
• Fixed and Stable Transmission (FAST) for consistent infrared transmission
  rates over the life of the window
• Impervious to shock and vibration
• Unconditional lifetime warranty on the IR window for the life of the electrical
  equipment