Archives for 2018

Preventative Maintenance Discovers Issue Before It Causes Downtime Decatur Industrial Field Service Team Finds Brush Shunt Abrasion

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.

Questions from Customers

“It’s 200 HP, why can’t you repair it?”

We get this question quite often. Yes, we can fix it…it’s just not economical to do so when something runs to catastrophic failure causing tremendous damage. New shaft, damaged core laminations, rewind, etc…

When equipment runs to complete failure, the total cost of ownership goes up due to unplanned emergency maintenance, excessive repair/replacement costs, downtime, and of course, safety. Ask our team how we can help take care of your assets to extend equipment life and reliability. Let’s get rid of motor killers and win the war against downtime!

Nameplate Speed vs Actual Speed

Identifying the speed of the motor is important for proper data analysis in many predictive technologies like electric motor testing and vibration analysis. It is not uncommon to identify a slight difference between measured speed and nameplate rated speed at the listed nameplate full load amps (FLA). NEMA MG1 allows +/- 20% of the difference from synchronous speed to rated speed under rated conditions. Although technologies, like the PdMA MCEGold software, may provide a field calibration of the speed search algorithm to allow for these differences, we should not automatically dismiss them as inaccurate nameplates. Instead we should evaluate the possible anomalies that could result in speed changes to verify a problem does not exist. Examples of anomalies affecting the measured speed to FLA relationship include a rotor cage anomaly reducing the operating speed, reduced operating voltage increasing the current amplitude for a given load, and a frequency change, which directly affects the synchronous speed. Always assume the nameplate is correct, until you prove it is not.

Help Us Help You: What Customers Need to Know when they Call with an Emergency Repair

A customer calls us.

Emergency repair needed right away.

The D.I.E. truck is on its way to get the repair.

But…we can’t load it yet…why???

When you call us with an equipment emergency, the worst thing that could happen is for a delay to occur because the motor, pump, or gearbox still has oil lubrication in it.

We never want our customers to be in this situation, so here’s what you need to know:

Illinois Department of Transportation (IDOT) regulations require permits for hazardous material and it must be in proper containers. The oil contained in a motor or gearbox can easily leak out onto the truck and then onto the ground causing an environmental issue.
Secondly, oil in the motor can easily slop around into the coils while bouncing down the road. This can turn a recondition into a much more expensive rewind due to oil saturated coils.

For additional clarity on transportation/shipping guidelines for equipment and what you can do on your side, click here.

Oil from transport — Oil in the bottom from transport.

Avoid Pump Blockages & Prevent Water Hammer

You asked. Siemens listened.

The new 3RW5 soft starters feature advanced pump control. Whether its to avoid blockage or prevent water hammer on the pipes, the 3RW5 soft starters can help you improve your water operations. These starters set their own parameters and configure themselves to communicate across your network; saving money & time.

3RW5 family of soft starters is a comprehensive, soft starter portfolio for simple to demanding motor starting applications. The family provides energy efficient switching, functionality for any application and digitalization for cloud-based analysis. These starters are ready for the Internet of Things (IoT), being easily integrated with most industrial communication networks. Communications via Profinet, Modbus and Ethernet IP, along with HMI panels, are available across the entire product range. This new family was also built with your motor application in mind; whether your motor application is for pumping, fans, or crushing, the 3RW5 soft starters can handle each and every load; giving you peace of mind.

Reduce Costs – Click here.