Detecting Temperature Abnormalities in Bus Ducts Early for More Efficient Maintenance

What if you could detect signs of abnormalities in bus ducts (bus bars) quickly during maintenance and inspection work and respond to them at just the right time? Yokogawa DTSX monitoring solution constantly monitors connections that tend to deteriorate over time and contributes by pinpointing abnormality locations and reducing workload of maintenance personnel, helping to ensure stability in plant operations.

Overview

Because bus bars are conductors that carry large electrical currents to manufacturing equipment, they are often covered with bus ducts, making visual inspection difficult. In addition, bus ducts (bus bars) are generally routed through ceilings, high places, or under floors, and it is not unusual for maintenance and inspection to require dangerous or harsh conditions.

The Fiber Optic Temperature Sensor DTSX provides a solution that contributes to stable plant operations by enabling efficient and accurate maintenance of bus ducts (bus bars).

Customer Challenges

Loose Bus Bar Connections

Bus bar connections and branches are generally bolted or clamped. A bolted connection, for example, may loosen due to an earthquake or a temperature rise in the bus bar itself, and this can lead to various risks or accidents.

Bus bar connections joined with bolts

Power Supply Interruption Risk

If the bolts used in the bus bar connection loosen, this may lead to an increase in electrical resistance in the area, causing temperature to rise. Overheating causes greater electrical resistance, which raises the possibility of operational shutdown due to damage in the bus duct (bus bar) and stoppage of electrical supply.

Increased Workload in Maintenance and Inspection

Some methods for maintenance and inspection include attaching thermo labels to bus ducts near bus bar connections and making patrols using thermal cameras. However, bus ducts (bus bars) can be connected several hundred meters in length or more, and visual inspection of such a huge number of connection points is no easy task.

Challenge of Retaining Personnel Due to Harsh Working Environment

In many cases, bus ducts (bus bars) are routed inside factory ceilings, in high places, and under floors. Although the stable operation of bus ducts (bus bars) requires constant monitoring, the working environment is harsh and can be unsuitable for human monitoring, so retaining personnel can be a major challenge.

Bus ducts routed in high places

Products & Solutions

1. Constant Monitoring with Optical Fiber Temperature Sensor

DTSX is a temperature sensor that can provide 24 hours, 365 days monitoring of temperature changes over long distances and wide areas using sensing technology that takes advantage of the characteristics of fiber optic cable.

DTXS can be laid out following the path or shape of the object to be measured, so it can be laid on the surface of bus ducts, contributing to predictive maintenance of bus ducts (bus bars).

2. Locating Abnormalities without Effects of Electromagnetic Noise

Bus bars that carry large currents cause strong electrical fields around them, making it difficult to measure temperatures with thermocouples or other electrical sensors. Thermal cameras cannot be used to monitor bus bars because they are spread over wide areas and complex routes.

However, DTSX uses fiber optic cables that are unaffected by electromagnetic noise even when subjected to strong electrical fields, so they can accurately and quickly identify abnormal overheating locations, allowing appropriate action to be taken.

3. Making Bus Duct (Bus Bar) Maintenance and Inspection More Efficient

DTSX can quickly and accurately monitor temperature distribution every one meter and pinpoint abnormal overheating location, contributing to faster initial response.

If any signs of abnormality are found in the bus duct (bus bar), bolts can be tightened and other work can be performed at the appropriate timing, helping to make maintenance and inspection work more efficient.

Anticipated Benefits

-Provides Constant Monitoring Over a Wide Area

It can provide accurate temperature monitoring with no blank areas, even when there are strong electrical fields or complex areas for measurement.

-Enables Predictive Maintenance of Equipment

It provides 24 hours, 365 days monitoring without missing any temperature changes, contributing to predictive maintenance of equipment.

-Contributes to BCP

It prevents power supply shutdowns caused by bus bar temperature abnormalities, minimizing the losses that result from production cuts, late delivery penalties, and lost opportunities.

-Reduces Maintenance Personnel Workload

It optimizes the intervals between inspections, realizing easier workloads for maintenance workers.

How Temperature Monitoring with DTSX Works

Measuring Temperature Using the Intensity of Raman Scattered Light

Pulses of light launched into an optical fiber propagates down the fiber while producing backscattered light with different wavelengths from the launch of the light source. The intensity of this light, which is called Raman scattered light, correlates with the temperature, and DTSX uses this to monitor the temperature of the installation site.

Pinpoint Measurement Every One Meter

DTSX monitors temperatures at one-meter intervals by calculating the round-trip time and the speed of light launched into an optical fiber. For example, with a 6 km optical fiber, 6,000 temperature points can be measured. Monitoring points can also be pinpointed every one meter.