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Maintenance
Differentiating
Maintenance From Repair
A misperception that works against a high ROI for
maintenance is the failure to distinguish between maintenance and
repair. If people are busy repairing things, that's not a sign you are
fully using maintenance resources — it's a sign you are
underutilizing them.
The key is to identify those activities that reduce the likelihood
of
failures. Prioritize the planning and execution of those activities,
and
repairs will automatically drop in size and frequency — lowering
cost relative to output at the same time.
It may "look good" when a team restores operation in record time.
But
a wise manager will ask why that operation went down to begin with, and
what you are doing to keep it from going down again. You should be
asking those same questions.
Two Ways to
Reduce
Maintenance Costs
Create and maintain kits for specific equipment.
"Kitting" eliminates wasted steps. While you may end up "carrying" some
extra supplies, tools, and possibly test equipment, you will reduce the
labor costs of working on certain equipment — especially key if this
work requires downtime. A case in point: One factory had a stamping
machine that required frequent maintenance attention. Without kitting,
the maintenance techs made repeated trips to the shop for the same
things they needed every time. Rather than pay them to walk back and
forth, the smart approach is to keep a locker stocked at that stamping
machine.
Appoint experts. Give one person the responsibility to
understand the ins and outs of a particularly important piece of
equipment. This would be the "go-to" person who studies the manuals,
goes to training, and contacts the manufacturer for updates and
information. Give this person "ownership," and hold him or her
accountable for knowing that equipment and watching or reviewing any
work done on it. "The devil is in the details." When everyone is a
generalist, nobody takes care of those details. This practice works
best
when you spread "ownership" around so everyone "owns" something. This
practice is at its worst when one person "owns" all the critical
equipment.
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Repair
Electrical
Troubleshooting Quiz
- If lights briefly flicker on a clear day, what
should your follow-up action be?
- A 400A breaker trips, and you investigate. You find no ground
fault,
and you reset it. You use a recording meter and monitor that circuit.
Later, the breaker trips on 200A. What should you do next?
The answers to these questions appear at the end of this
newsletter.
Reduce Downtime
Through Communication
In most MRO environments, there's a gulf between
operators and maintenance people. The reason often goes back to "blame
game" politics at departmental meetings — nobody wants to be blamed for
missing this week's numbers, so people avoid identifying any cause that
could reflect back on their own department. This short-sighted attitude
prevents those bad numbers from becoming good numbers.
To correct this, clearly and consistently communicate that you need
operators to describe events near the time of failure as accurately as
possible or you can't prevent future failures. Most failures are due to
human error, but human error is often preventable with changes to
equipment and/or procedures. So operators need to understand that if
they do something that causes a shutdown, you want to identify how to
make their job easier and less prone to mistakes. Possible cures
include:
- Adding delays in controls (easily done in the PLC)
- Reconfiguring man machine interfaces (MMI)
- Clearing up signage (over time, signage tends to bloat)
- Installing guards, moving switches, or similar
- Changing the process
- Replacing or modernizing equipment.
But, you can't do any of these things until you know the real story.
Gain operator confidence by backing your promises with action rather
than blame. In so doing, you will eliminate previously "hidden" causes
of failure.
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Operation
The Practical
Implications
of OSHA 1926.104
This regulation addresses safety belts, lifelines, and
lanyards (SLL). In construction, the rules are well-understood -- but
typically misunderstood in MRO. Falls consistently rank in the top
three
for causes of industrial deaths — attention to fall SLL is
important.
Some rules of thumb:
- Don't re-use any SLL after a fall — take it out of service and
replace it.
- Inspect SLL before use — during a fall will be too late.
- Secure lifelines above the point of operation, and to structural
member or point of anchorage that can hold at least 5,400 pounds
(OSHA's
estimated equivalent force in a fall).
- Never secure lifelines to any raceway, not even rigid
conduit.
Replacing A Circuit
Breaker
When a breaker fails inspection, consider replacing it.
With the advances in breaker technology, breaker replacement offers
many
potential benefits. Consider new features that improve reliability,
maintainability, and serviceability. And it's also possible your
original breaker is no longer suitable for the load(s) on that circuit.
Before specifying a replacement breaker, look closely at the load
characteristics — which may have changed over time. You may need an
entirely different breaker design, compared to what you were using.
Assess the entire panel, if the breaker needs replacement due to age.
Otherwise, you will get into a costly situation of "chasing your own
tail" where increasing the risk of unplanned downtime.
If you are replacing a service entrance panel, schedule a grounding
system test for the same day as the shutdown for the replacement
work.
NEC on the Production
Floor
Many people skip over Article 100. Perhaps that's
because the idea of reading "vocabulary words" isn't very exciting. But
words convey meaning, and misunderstanding the meaning of certain words
has gotten many people killed in this industry. One of the major
misunderstandings is the idea that grounding (earthing) equipment and
metallic objects provides equalization of potential. Bonding does this,
but grounding does not.
Take the time to read Article 100 definitions carefully. If you
haven't clearly understood the definitions of grounding and bonding
before, doing so now will shed some light on why your PLC has
intermittent problems, you had a flashover, electronic power supplies
mysteriously fail, or that water fountain shocks people who drink from
it.
Quiz Answers
Answers to
Electrical
Troubleshooting Quiz
- The typical reaction is to assume a glitch in
the utility supply. But the problem may be far more dangerous than
that.
The list of possible causes is long. To find the needle in the
haystack,
start at your power monitor (if you don't have a power monitor, this
situation could make you wish you did). If you don't find an anomaly
through your power monitor, inspect and test your lighting supply
transformer. You may also have problems with insulation integrity,
grounding, or bonding.
- Test that breaker. This may require removing the breaker. If you
are
unfamiliar with breaker testing, hire a NETA-certified testing firm to
perform the testing. Before opening the breaker, isolate (lockout and
tagout) each load on that breaker. Then, remove that breaker from
service. Before closing the breaker, walk down the loads to ensure they
are still isolated. Then, close the breaker to return it to service.
Finally, bring each load back online one at a time. Don't operate a
fully-loaded breaker -- the last thing you ever see might be a coworker
wildly gesturing for you to stop.
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