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Training cuts the number of hoist starts by half

North America, June 2013

Challenge: Automotive supplier’s hoist brakes and hoist motors wearing out at a rapid pace

Solution:  Training cuts the number of hoist starts by half

 

In June 2013, an automotive supplier in the US had a recurring issue of having to frequently replace the hoist brakes on their cranes. The company was mystified as to why they were going through hoist motors and brakes so quickly.

After replacing their equipment with a Konecranes CXT crane the company got access to the usage data and remote monitoring where they saw a significant number of hoist motor starts and emergency stops. In the first month that the crane was in operation it had an average of four emergency stops per day, adding up to about 20 per week, or 80 per month. In addition to that, there were 20,000 hoist motor starts per week, mounting up to around 80,000 each month.

“Every emergency stop burdens the brake 50 times more than a normal braking situation. Every hoist motor start, on the other hand, directly affects the hoist brake itself, the contactors, the control equipment and the hoist motor,” says Jim Skowron, Regional Vice President of Sales for Konecranes’ Service division in the Americas.

Hoist motors for a normal service duty class are designed to perform 25,000 to 30,000 starts a month over a 10 year life. In order to extend the life to 30 years, the design limit for the same duty class is 10,000 starts per month.

“This customer was on pace to replace the hoist motor every two to three years based on the current operating habits. It was discovered that the operators were pressing the up and down controls repeatedly to set their product instead of using the speed controls provided in the hoist.”

Proper operator training is a long-term investment

After investigating the numbers, the customer arranged for an on-site training course by the local Konecranes service branch. As a result, the number of emergency stop occurrences decreased from 20 per week to just five. The hoist motor starts dropped from 80,000 per month to less than 40,000 – all the while performing the same material handling processes.

“The benefit to the customer was easy to see. They had two options: either invest in a training class that provided ‘hands on’ instruction on site with their own equipment or continue to pay thousands of dollars for hoist replacement brakes and motors,” attests Skowron.

Additionally, Konecranes’ remote monitoring has a few different formulas that calculate the theoretical remaining lifetime of a hoist and hoist brake based on its Design Working Period (DWP). This enables better preparation for replacements.

Remote monitoring improves safety

Konecranes TRUCONNECT® remote monitoring portal collects a wealth of information. It shows safety data including the number of overloads, emergency stops and hoist motor over temperatures. Operating statistics like Efficiency Duty (ED), calculating the number of minutes each day that the crane has been driven over the motor’s efficiency limit, are also provided.

“If we know the ED percentage is 60 then the motor is designed to run continuously for six out of every 10 minutes. If the customer is operating consistently above this, we can predict that there will be premature motor failures, brake issues or other types of wear.”

The information is collected with a diagnostic unit. Every 24 hours, all the information is sent via a modem to the centralized data handling center and downloaded into a customer web portal. Safety alerts are sent immediately as an e-mail or smartphone alert.

“The important benefit of remote monitoring is that abnormal functions can be observed early enough before they develop into big problems. Equipment lasts longer and breaks down less often. In the end, remote monitoring supports a safer working environment,” says Skowron.

 

Text: Venla Pöyliö
Photos:Konecranes

Key advantages

  • With TRUCONNECT, you can follow equipment usage in real time and can track down particular alerts or incidents. Plus, the TRUCONNECT portal provides information on causes that the management should be aware of. It also recommends actions that can be taken, such as training or identifying power supply quality issues.
  • Data is secure. Konecranes uses data security systems in remote monitoring that are similar to those used in online banking.