Predictive maintenance (PdM) or condition based maintenance (CBM) is to monitor predefine parameters over the time and predict it’s failure time to make corrective repair to restore its normality.
This is the last and final stage of preventive maintenance which aims to optimize maintenance period and costs by monitoring the trends of equipment deterioration trends.
It is possible to sustain zero breakdowns through TBM itself but there may chance to replace some spares before their life ends which means over and costly maintenance. So, By increasing scope of CBM we can optimize maintenance cost and time.
It targeted at parts that have had serious breakdown in pasts and or parts that cause costly damage (Total downtime costs) when they fails and due to high costs of spares it is not economical to consider it under TBM.
Pre-requisites for PdM : rushing to PdM diagnostic tools or service yields no results
a) Identify accelerated deterioration factors and implement thorough restoration and improvement through JH
b) Un expected failures can be reduced. Consider in-depth Time Base Maintenance (PM / TBM) in order to find the deterioration pattern
c) Sufficient data to compare with ideal.
d) Failures patterns are not frequent and a costly affair for both to afford reactive maintenance and keeping spare.
e) Decide control value for each deterioration pattern
Prediction Methods
1. Measuring electrical motor currents, temperature, Insulation level: Monitoring electrical motors current and temperature trends tell you about Mechanical side problems, aging of motors.
2. Thermal imaging – It is a non-contact temperature capturing device which collects temperature data from multiple points and store in a 2D profile. Some thermal imagers can compare present profile with base profile and help to detect the problem area. Excellent and versatile method of predicting problems. Commonly use for .
i) Measuring bearing temp. of large motors
ii) Identify leaks
iii) Loose connection in electrical circuits.
iv) Hot-spots in electronics circuits
3. Motor currents wave form – these spectra will tell us bout jerk loads. As example, If we want to check belt conveyor motor then we have to monitor coefficient of friction between belt and pully which is decreasing with time. If slippage is occurring then produced torque also decreasing which in proportion with load current. So, We can detect slippage by analyzing wave form of load current).
4. Vibration Analysis : Vibration data. gives performance evaluation for Rotating machinery (identifying potential defects such as bearing failure, gearing faults, drive belt problems, bent or misaligned shafts, coupling faults and driven element faults. Structural failures such as poor mounting, resonances, and feedback from other machines
Popular method is shock pulse method (SPM). It measures two value. One is carpet value and another is Maximum value..
5. Engine oil analysis (Used oil analysis and ware particle analysis). Used oil analysis determines the condition of the lubricant itself, determines the quality of the lubricant, and checks its suitability for continued use. Wear particle analysis determines the mechanical condition of machine components that are lubricated. Through wear particle analysis, you can identify the composition of the solid material present and evaluate particle type, size, concentration, distribution, and morphology.
But again, reliable predictive maintenance equipments are precise but costly too. So, it need to be use cautiously to determine diagnostic process and frequency to optimize maintenance time and cost. (One of the powerful PdM paradigms is not to repair equipment too early or too late
Another difficulty is to gather data for perfect ideal one to compare. So, prerequisites must be fulfilled.
Scope of PdM in Indian scenario:
In Indian scenario, PM (TBM) is still a popular method over PdM which is not so popular because
1.Less knowledge on technical know how on PdM analysis methods and so, less confidence on these technologies.
2.For in-house PdM it needs a big investment for purchasing hardware which in not feasible in most of the cases.
3.For operating and analyzing it needs a specifically trained and experienced personnel which is not available.
4.In European country, there are many private agencies who offer predictive maintenance services with up to date equipments. But here due to less requirement and awareness there is no such strong customer base and so, no such frequent services available. (Shock Pulse Method Services available for compressor and generators but other sources of services still I don’t know )
5. Less awareness on energy audits and survey in general industries
Standards
Reference these standards(curtsy :Fluke website) when creating safe standard work procedures for PdM program.
International Electrical and Electronic Engineers standard IEEE-90 describes the elements of an EPM program, including safety, while 1584â„¢-2002 provides a guide for arc flash hazard calculations and ANSI/IEE C2-81 National Electrical Safety Code governs heavy industrial installations.
MTS-2001 Maintenance Testing Specifications for Electrical Power Distribution Equipment and Systems from the International Electrical Testing Association (NETA), www.netaworld.org, contains set of step-by-step standard procedures for inspecting, testing and evaluating system components and appendices that recommends maintenance intervals for various components.
Standard NFPA 70B Recommended Practice for Electrical Equipment Maintenance from The National Fire Protection Association provides a PdM program overview, as well as an appendix with sample tests and record forms. For each component of the electrical system, it describes how you should inspect and test each sub-element. For example, in the section on rotating machinery it covers stator and rotor windings, then goes into brushes, collector rings, commutators, and then bearings and lubrication.
• NFPA 70B also includes a section on test methods, including insulation testing, transformer turns-ratio testing, circuit breaker testing and ground impedance testing, and power quality issues such as harmonics, transients, unbalance, sags and swells.
• Also refer to NFPA 70E Standard for Electrical Safety in the Workplace for safety training, procedures, personal protective gear (PPE) requirements, and lockout/tagout procedures.
Occupational Safety and Health Administration OSHA 29 CFR, 1910 Subpart S Electrical and Subpart I Personal Protective Equipment Safety standards for electrical systems, safe work practices, maintenance requirements.
ISO 6781 International Standards Organization (ISO) (American National Standards Institute) discusses thermal insulation, qualitative detection of thermal irregularities in building envelopes, and infrared methodology.
ASTM International http://www.astm.org ASTM E 1934, 1213, 1311, 1316, and 1256 Standard guide for examining electrical and mechanical equipment with infrared thermography, plus additional thermography references in ASTM 1060 and 1153.
I am really loving the theme/design of your web site.
Do you ever run into any web browser compatibility problems?
A handful of my blog readers have complained about my site not working correctly in Explorer
but looks great in Chrome. Do you have any advice
to help fix this problem?
Nice weblog right here! Additionally your site a lot up fast!
What host are you the usage of? Can I get your associate
hyperlink for your host? I wish my web site loaded up as quickly as
yours lol
My spouse and I stumbled over here from a different page and thought I should check
things out. I like what I see so i am just
following you. Look forward to checking out your web page yet
again.
Hurrah! After all I got a weblog from where I be capable of in fact take valuable facts
regarding my study and knowledge.
Howdy! I know this is kinda off topic but
I was wondering which blog platform are you using for this website?
I’m getting tired of WordPress because I’ve had problems with hackers and I’m looking at options for another platform.
I would be great if you could point me in the direction of a good
platform.
Thanks a lot for sharing this with all folks you really recognise what
you are speaking approximately! Bookmarked. Please also consult with my website =).
We could have a hyperlink trade contract between us
Whats up very nice website!! Guy .. Excellent ..
Superb .. I’ll bookmark your blog and take the feeds additionally?
I am happy to seek out numerous helpful info here in the publish, we want
develop more techniques on this regard, thank
you for sharing. . . . . .
Hello to all, the contents existing at this web
page are genuinely remarkable for people experience, well, keep up the nice work fellows.
This is really interesting, You are a very skilled blogger.
I have joined your rss feed and look forward to seeking more
of your magnificent post. Also, I’ve shared your web site
in my social networks!
Ahaa, its fastidious conversation on the topic of this post at this place at this website, I have
read all that, so now me also commenting here.
Hey! Do you know if they make any plugins
to protect against hackers? I’m kinda paranoid about losing
everything I’ve worked hard on. Any recommendations?
I am not sure where you’re getting your info, but great topic.
I needs to spend some time learning more or understanding more.
Thanks for excellent info I was looking for this information for my mission.
Hello this is kind of of off topic but I was wondering if blogs use WYSIWYG editors or if
you have to manually code with HTML. I’m starting a blog
soon but have no coding skills so I wanted to get advice from someone with experience.
Any help would be greatly appreciated!
I have fun with, result in I discovered exactly what I was
looking for. You’ve ended my 4 day long hunt!
God Bless you man. Have a great day. Bye
It’s going to be finish of mine day, except before finish I am reading this enormous
piece of writing to improve my knowledge.
Fine way of explaining, and good post to take information concerning my presentation focus, which i am going to convey in academy.
I was suggested this web site by way of my cousin. I
am not sure whether or not this post is written through him as nobody else realize such special approximately my
problem. You’re incredible! Thanks!
Thanks for the marvelous posting! I certainly enjoyed reading
it, you might be a great author. I will remember to bookmark your blog and will often come back very soon. I want to encourage you
to continue your great job, have a nice morning!
Hi there to all, for the reason that I am genuinely eager of reading this web site’s post to be updated on a regular basis.
It consists of pleasant information.
Hi there just wanted to give you a quick heads up.
The words in your post seem to be running off the screen in Ie.
I’m not sure if this is a formatting issue or something to do with internet browser compatibility but I thought I’d post to let
you know. The layout look great though! Hope you get the issue fixed soon. Many
thanks
I know this site presents quality depending posts and extra information, is there any
other web site which offers such information in quality?
Wow, wonderful weblog layout! How lengthy have you been running a blog
for? you made blogging look easy. The overall glance of your site is great, as well as the content material!
My brother recommended I might like this blog.
He used to be totally right. This post actually made my day.
You cann’t imagine just how a lot time I had spent for this information! Thank
you!
Thanks for some other wonderful post. The place else
could anyone get that type of information in such an ideal
means of writing? I’ve a presentation next week, and I am at the search for such information.
I don’t know if it’s just me or if perhaps everybody else encountering problems with your site.
It seems like some of the written text in your posts are running off the screen.
Can someone else please comment and let me know if this is happening to them too?
This could be a problem with my internet browser because I’ve had this happen before.
Kudos
Hi there would you mind letting me know which hosting
company you’re using? I’ve loaded your blog in 3
different internet browsers and I must say this blog
loads a lot faster then most. Can you suggest a good hosting provider at a reasonable price?
Thanks a lot, I appreciate it!
Pretty nice post. I just stumbled upon your weblog and
wished to say that I’ve truly enjoyed browsing your blog posts.
After all I’ll be subscribing to your rss feed and I hope
you write again very soon!
Your style is unique compared to other folks I have read stuff from.
Many thanks for posting when you’ve got the opportunity, Guess I
will just bookmark this blog.
Hi everybody, here every one is sharing such
knowledge, therefore it’s fastidious to read this web site, and I
used to visit this blog all the time.
Thank you a lot for sharing this with all folks you really know what you are talking approximately!
Bookmarked. Kindly also talk over with my site =).
We could have a hyperlink alternate agreement among us
What’s up to every one, the contents present at this website are genuinely amazing for people knowledge, well,
keep up the good work fellows.
It is truly a nice and helpful piece of info. I’m glad that you just shared this useful information with us.
Please stay us informed like this. Thank you for sharing.
It’s going to be ending of mine day, except before finish I
am reading this fantastic piece of writing to improve my
experience.
This is the perfect webpage for anybody who really wants to find out
about this topic. You understand a whole lot its almost hard to argue with you (not that
I actually would want to…HaHa). You definitely put a fresh spin on a subject that’s been discussed for years.
Excellent stuff, just wonderful!
Usually I don’t learn post on blogs, however I would like to say that this write-up very compelled me
to take a look at and do it! Your writing taste has
been surprised me. Thank you, very nice post.
I think the admin of this website is truly working hard in support of his web page, as here every material
is quality based stuff.
Excellent, what a weblog it is! This webpage provides valuable data to us, keep it up.
I visited multiple sites except the audio quality for audio songs existing
at this site is genuinely wonderful.
Unquestionably believe that which you said. Your favorite justification seemed to be at the web the
simplest factor to consider of. I say to you, I definitely get annoyed
at the same time as people think about worries that they plainly don’t understand about.
You managed to hit the nail upon the highest and also outlined out the whole thing with no need side-effects , people could
take a signal. Will likely be again to get more. Thanks
Greetings! Very useful advice in this particular article!
It’s the little changes that produce the greatest changes.
Many thanks for sharing!
Its like you read my mind! You seem to know a lot about this, like you wrote the book in it or
something. I think that you could do with a few pics to drive the message home a little bit, but instead of that, this is excellent blog.
A great read. I’ll certainly be back.
I know this web site gives quality depending articles
or reviews and other information, is there any other website which
provides these things in quality?
I do not know whether it’s just me or if everyone
else encountering problems with your blog. It looks like
some of the text on your posts are running
off the screen. Can somebody else please comment and let me know
if this is happening to them too? This might be a problem with my browser because I’ve
had this happen previously. Thanks
Heya i am for the first time here. I found
this board and I find It truly useful & it helped me
out much. I hope to give something back and aid others like you helped me.
I have learn a few just right stuff here. Definitely value bookmarking
for revisiting. I surprise how so much attempt you place to create
the sort of fantastic informative web site.
Leave us a comment