We covered the entire range of use from data management, data input, testing, and interpretation of test results using the AWA instrument.

Every dollar saved truly makes a difference in today’s environment. However, when we can help put a $1 million dollar figure in front of a savings, it’s news worth sharing.

Decatur Industrial offered to provide training on the SKF Baker AWA (Automated Winding Analyzer) beyond what the manufacture offered.  The training would be provided to the customers’ electricians responsible for medium-voltage machines (up to 4,000HP) and technicians responsible for low-voltages machines prior to their upcoming outage. Critical motors would need to be analyzed with the SKF Baker AWA for service acceptance.  We held true “hands-on” training with the assistance of the customer supplying several motors from their warehouse.

In the process of testing, we discovered two issues:

1. A 4000 HP motor failed insulation resistance to ground and the Polarization Index (PI) test, indicating that moisture may be an issue.
2. A Coal Mill motor was found to have an out of range Pulse –to- Pulse Error Ratio on the SKF Baker AWA. This indicated that the motor had a defect in the turn-to-turn insulation of the coil wires. (Not a Decatur Industrial rebuild!)

What Happened Next:

1. 4000 HP Motor: They were able to dry the moisture from the windings with space heaters to obtain a satisfactory insulation resistance with the SKF Baker AWA instrument training we provided.
2. Coal Mill Motor: Sent to D.I.E. repair shop for a rush rewind and repair which we were able to accomplish within their outage. With our focus on solutions based reliability, we suggested and made improvements over the OEM winding design.
   1. Uprate winding – remove excess slot filler and redesign the coils to provide an 8% copper increase
   2. Implemented state of the art corona protection in the stator coils.

Our thorough evaluation of the motor also found mechanical issues. This resulted in machining and repair of both bearing outside diameters to properly OEM bearing-to-housing machine tolerances.

Calculated Total Cost of Ownership Savings:

4000 HP Motor

It could have experienced an immediate failure or a potentially irreversible ground insulation degradation if put into service – both resulting in unplanned downtime and emergency maintenance!

Coal Mill

• $8,000 – $16,000 per day (depending on prices and load demand)
• PA Fan – $25,000 – $50,000 per day
• Plus labor rebuild costs

Coal Mill: $168,000 to $336,000 plus motor repair

PA Fan: $525,000 to $1,050,000 plus the motor repair

Decatur Industrial Electric was sent in an open drip proof motor for repair. The debris inside the motor was evident immediately upon inspection. After consulting with the customer, we discovered they had been experiencing short motor life with these motors and had not been provided an option to replace the open drip proof with a different motor.

Our experts worked with the customer to explore the best motor options for this application. The motor was driving a water pump in the facility therefore it was our recommendation to install a totally enclosed fan cooled (TEFC) vertical hollow shaft motor which prohibits debris from entering the motor.

A TEFC motor has an initial higher purchase price than the open drip proof motor. However, the extended life expectancy yields a lower cost of ownership. The customer will save on motor purchases, repairs, and unscheduled downtime.

Decatur Industrial Electric has been a top partner and distributor for U.S. Motors for decades. To find out more, visit: https://www.decaturindustrial.com/products/manufacturers/manufacturers-u/

1 Minute Tour of Asset Management Floor at Decatur Industrial!

Decatur Industrial Electric has many customers who utilize our Asset Management Program (AMP.) The goal of AMP is to properly store and maintain customer’s equipment so it’s ready to be installed into service at a moment’s notice.

This particular customer was bringing back online a portion of their plant that had been down for a scheduled outage. They realized they had a motor that needed reconditioned and wanted done immediately as an emergency rush repair.  Decatur Industrial AMP application specialists reviewed the customer’s inventory and found they had a spare that would be excellent in the application.

By not rushing a repair and recondition, this customer was able to save thousands, plus utilize a more reliable motor asset they already had in stock.

If you are interested in equipment storage and maintenance at Decatur Industrial Electric, contact Terry Cox today at 217-428-6621 or tcox@decaturindustrial.com

AMP Benefits Include:

• Environment controlled storage & maintenance per OEM specs +
• Warranty tracking
• Web portal with asset tracking updated every 24 hours
• 24/7 Logistics

When you hear “account manager” you most likely think sales.  At Decatur Industrial, an account manager is so much more than a sales person.  Our Account Managers are Reliability Specialists and can help provide technical support and application expertise.

A power generation facility was pulling a 4000 HP fan motor in order to remove a coupling hub worth over $30,000 from the motor’s shaft to be installed on their spare. Removing these couplings has always proved a challenge due to the .011” interference fit between the motor shaft and coupling bore.  The attempt by the plant to remove the coupling was again unsuccessful.  The Reliability Maintenance Supervisor decided to reach out to Kent Henry, D.I.E. Reliability Specialist, for knowledge support with this particular situation.

Once on-site, Kent met with the Supervisor and the plant technicians to review how they initially approached the project. They had set up the hydraulic input to the coupling which was intended to expand the coupling for removal per the OEM training. From that information, we formulated a new plan we felt would be successful and included two critical adjustments:

1. We changed the hydraulic system oil weight to provide more lubricity between the shaft and coupling hub bore.
2. Rather than applying abrupt hydraulic pressure up to 18,000 psi to the coupling hydraulic ports and expecting the coupling to move, we used reduce pressure planning to apply this force for a longer period of time.

As it turned out, about 70% of that maximum pressure was all that needed to be applied hydraulically to expand and lubricate the coupling hub.  Through our method, the customer saved potential damage to the $30,000 coupling, the motor shaft, and we saved them the time of having to send out to a repair facility.

Click on the pictures to enlarge. 

Decatur Industrial Electric recently received an emergency field service request from a steel industry customer to troubleshoot the controls and inspect a 750HP, 900 RPM M-G set that would not start.

During inspection we found that the generator portion of the M-G set had serious issues with the interpole insulation. Between the core iron and the coils, the core insulation had completely disintegrated and turned to powder.  Additionally, the line leads on the motor portion of the unit were oil soaked and swollen. It was determined that the unit needed to be removed and repaired at Decatur Industrial because it was impossible to properly test the unit in its current condition.

Upon arrival at our shop, we completely reconditioned the M-G set, which included removal of all the interpole coils, reinsulation, and a VPI treatment. We also rewired the DC internal connection and releaded the AC motor stator.  Finally, we were able to properly troubleshoot the control problem and repair the faulty contacts.

Although we were unable to initially troubleshoot the controls due to the deteriorating insulation on the generator side of the unit, we saved the customer the cost of a complete M-G set rebuild which can cost upwards of $200,000. They paid less than half of that amount for our repair.