Infrared
Thermography
Sample
Report Data
Industry
Case Study:
Infrared
Predictive Maintenance Solutions
Abstract
On
July 6, 2001 an electrical fire broke out at a plastics manufacturing
plant located in southern Ontario. The fire and subsequent damage
to the distribution network downstream of the fault could have
been avoided. By integrating Infrared Thermography (IRT) within
a comprehensive predictive maintenance program businesses have
the ability to foresee failure of critical equipment components
under stress modes that might otherwise be missed. Most importantly,
the cost of implementing an IRT PdM program is more than offset
by the savings in maintenance and repair costs, revenue-loss
due to unscheduled shutdowns, and insurance costs.
Background
The
following case study will show the benefit, to both industry
and its insurers, of utilising Infrared Thermographic (IRT)
inspections as part of a comprehensive predictive maintenance
program for electrical distribution equipment.
More
insurance firms are seeing the advantages of having their industrial
and commercial policyholders perform regular IRT predictive
maintenance inspections on critical and costly components of
their electrical distribution network. In many cases, the realised
savings in insurance claims due to premature equipment failure
have pushed insurance companies to obligate their clients to
perform regular IR inspections as a term of their policy renewal.
Although this might seem onerous for the client, study after
study has shown that the financial and safety benefits to industrial
and commercial facilities far outweigh the costs of implementing
and maintaining an effective IRT program (see Table 1).
Table 1.
| IRT
predictive maintenance? |
Premature
equipment failure |
Possible
results |
Costs
to client |
Financial
costs to insurer |
| No
|
Likely
not detected |
- Unscheduled
shutdown
- damage
to critical equipment
- safety
hazards to personnel
|
- Cost
of damage repairs
-
lost revenue due to unscheduled shutdown·
- potential
liability for personal injury
|
- Property
damage claims·
- possible
health insurance claims
|
| Yes |
Most
likely detected |
|
- Cost
of inspection
- maintenance
costs
|
None |
IR Inspection
On
June 26, 2001 an infrared thermographic inspection was carried
out at the above-mentioned plastic manufacturing plant. The
inspection run was limited to two main electrical distribution
boards situated in the West and East buildings respectively.
The
inspection was conducted by a Level II Certified thermographer
using the AGEMA 570 long-wave infrared camera, with a 24-degree
lens.
Fig.
1. Looking at the visual image (bottom) of this
3-phase capacitor bank gives no hint as to the impending
danger that the Phase A feeder connection imposes. The
thermogram (top), however, clearly betrays the existence
of a serious deficient connection. The problem in this
case could have been corrected with little interruption
to equipment operation.
|
|
Follow-up Events
It
is unfortunate that many businesses, which are new to the idea
of on-condition monitoring of equipment, often are reluctant
or even suspect of the reliability and effectiveness of implementing
corrective actions recommended as a result of IR inspections.
Often, resources are not fully utilised to help properly integrate
IR inspection runs and their results into the existing maintenance
program.
 |
Figure
2. The damage caused by the overload of this Phase
A conductor is significant. The oxidation of the copper
strands is evident. The soot residues also reveal the
severity of this phase-to-ground fault event.
|
For
whatever reasons, corrective maintenance actions to the capacitor
bank termination were delayed and the consequences are not new.
In fact, they are predictable and, most importantly, avoidable.
The ensuing electrical fault caused by meltdown of the conductor
insulation, a week after the IR inspection report was issued,
caused an unscheduled shutdown of a critical section of the
plant. As is obvious, any fire in a plastics plant, where volatile
and extremely flammable materials predominate, can quickly lead
to disaster. Fortunately the problem was contained and no one
was injured, but there was significant damage to the capacitor
bank. Durham York Electric & Communications Inc. was called
in to do the repairs, which kept the manufacturing line down
for half a day.
 |
Figure
3. An infrared inspection was conducted on the capacitor
connections subsequent to the repairs. As the image
reveals, all phase conductors were operating at relatively
similar temperatures, with similar loads on each phase.
Compare this thermogram with the one in Figure 1 above.
The difference in temperature rise is substantial. Without
the use of infrared thermography, this anomaly would
not have been evident to the naked eye, upon conventional
inspection.
|
Cost-Benefit Analysis
A
quick look at the figures below will convince most of the benefits
of employing predictive maintenance through the use of IR imaging.
Being able to see specific stress modes before they lead to
outright failure of a component or jeopardise worker safety
has its advantages. The analysis compares the on-condition IR
approach to the outdated maintenance standard of the preventative
or "if it ain't broken don't fix it" approach.
No
IR inspection or follow up
Cost
of electrical repairs including labour ..........................................
$ 1,700.00
Estimated lost revenue due to unscheduled ½ day shutdown...............
$ 20,000.00+
Total: $ 21,700.00+
IR inspection with corrective actions taken
Cost
of IR inspection .........................................................................$
695.00
Cost of implementing corrective actions ...............................................$
150.00
Total: $ 845.00
Total
savings to the company: ~ $ 21,000.00
Management Perspective
The
preceding scenario easily shows the financial benefit of implementing
a comprehensive predictive maintenance program through the use
of IR imaging. In this case, the company took the first step
in attempting to integrate IR inspections into an effective
maintenance program. However, the effectiveness of any on-condition
monitoring of equipment depends strongly on the proper co-ordination
of management and maintenance personnel and the efficient implementation
of corrective actions as recommended in the infrared thermographic
reports.
An
investment is needed at the start of any IR predictive maintenance
program to help integrate this tool and help realise long-term
costs savings. Both management and maintenance staff should
be educated on its application, logistics and most importantly,
what the inspection results say about the operating condition
of equipment critical to their business.
Conclusions
As
illustrated by this case study, long term cost advantages can
be realised through Infrared Thermography, by companies in any
almost industry sector. The effective use of Infrared Thermographic
Imaging reaches beyond simple electrical system inspections.
It can be applied in a myriad of different circumstances, such
as:
As
illustrated by this case study, long term cost advantages can
be realised through Infrared Thermography, by companies in any
almost industry sector. The effective use of Infrared Thermographic
Imaging reaches beyond simple electrical system inspections.
It can be applied in a myriad of different circumstances, such
as:
