No Higher Priority than Safety

This Decatur Industrial customer had several 800HP motors that required air filter changes at least once a month and sometimes once a week. Changing that filter required a ladder or rollaround staircase, which added time and safety concerns

With increased focus on safety in the workplace, the customer wanted to be able to change the filter from the ground. D.I.E. was engaged to engineer a solution so the motor performance would not be affected.

Our team modified the hood ductwork utilizing engineering data to maintain the same airflow while lowering the filters to allow safer and faster changes.

Contact Decatur Industrial today to see what modifications we can make to improve safety in your facility.

Additional gallery pictures:

Many customers use Decatur Industrial Electric for in-plant preventative maintenance (PM). It is essential to perform internal PM’s on DC, synchronous, and large electric motors as a part of managing facility assets because they have a huge impact on productivity and profit.

During a recent PM job at a customer site, our field service technician discovered brush shunt abrasion on a 750HP DC motor due to the brush shunt leads being too short and rubbing against the springs. Based on this finding, we proactively made a suggestion to add length to the brush shunts. They would go from a 4” shunt length to a 6”.

This simple fix cost the customer 94 cents more per brush. There are 6 rows of brushes at 4 per row, so 24 brushes cost $22.56, versus potentially:

• At minimum reconditioning the motor would have cost $23,500
• Or possibly leading to a rewinding the armature/recondition the fields at fields $48,700

Here is an example of the proper location of the shunt termination in relationship to the brush in the holder. This prevents the shunts from abrading on the brush spring coil edges.

Electric motors are often kept in a place or used in an application that makes them susceptible to contamination from the environment it is operating in and because of that, motor failures are accepted. However, as this customer discovered, sometimes it can be a different reason altogether. 

A Decatur Industrial Electric customer was experiencing frequent and rapid failure of their DC electric motors. The DC motors were used in a steel mill and were suffering up to four failures a month at a $6,000- $12,000 cost per failure – not including downtime and emergency maintenance costs.

Jeff Meyer, Director of Industrial Solutions, along with our team of technicians performed root cause failure analysis on several failed motors. Then, our team went to the steel mill to evaluate the motors and application in operation. During his evaluation, we discovered the customer was supplying the incorrect brushes for the load and application.  By having the wrong brushes installed, it was contributing to the contamination of the motor. After the correct brushes were installed, the failures stopped.  The next step?  D.I.E. technicians will be inspecting and performing routine DC motor maintenance at the plant during normal shutdowns to extend the motor lifecycle.

Are you experiencing repeated equipment failures in your facility?  Let Decatur Industrial partner with you to provide longer motor life.

Decatur Industrial Electric Saves Steel Customer through our Start-Up Process

One of the most effective strategies for avoiding unplanned interruptions is correct installation at the beginning of the equipment’s life. If installation and commissioning is carried out carefully using the correct procedures, it is an investment in the machine´s serviceability and reliability for its entire service life.

In this situation, a customer was looking to install vertical pump motors but they were having issues with the process.  Decatur Industrial was engaged and proposed putting together an “install kit” for each of their groups of vertical pump applications. After reviewing the equipment, our experts came up with the kit components.

Each kit has the following to discreetly address the mechanics needs for installation. 

(1) HEAD SHAFT

(1) HEAD SHAFT NUT

(1) LINE SHAFT COUPLING

(1) GIB KEY

(1) V-RING

We added the V-Ring as a failsafe, as it is non-standard and new for the application. It will sit immediately below the steady-bushing once it has been locked in place.  This prevents water from being forced between the shaft and the steady bushing bore.

By engaging Decatur Industrial Electric these kits allowed for proper installation and commissioning; and most likely a long life for these vertical pump motors.

Next steps: Vibration analysis, oil sampling, and electrical testing to monitor the motors health.

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