1 of

How to Develop the PM’s for a machine

A Step by Step Approach

Jim TaylorJim.taylor@machineryhealthcare.com

765-366-4285© 2009 MMSI

2 of

Failure After Overhaul

0

20 0

40 0

60 0

80 0

10 00

12 00

14 00

16 00

18 00

2 00 0

< 1 wk 1 – 2 wk 2 – 3 wk 3 - 4 wk 1 – 2 mo 2 – 3 mo >3 mo

Time a fte r o ve rha u l

3 of

4 of

Each Technology Is Optimized

Machine Healthcare is sub-optimized

Spreads cost over as many machines as possible

Minimizes cost per data point

Maximizes utilization of test equipment

Provides evidence of full work load to supervision

5 of

Is This the Best Way?Would you be happy with your doctor if on your annual physical he only tested your pulse rate?

And then sent you out to contract your own blood work and interpret the results?

Then based on that limited information, he makes the decision to do surgery.

A pump overhaul is surgery!

6 of

Technology Centered:Optimizes individual technology program

spreads cost over as many pieces as

possible

Minimizes cost per measurement

Provides full workload

Keeps equipment in use

Machine centered:Optimizes machine

health

Provide all needed information to assess

machines health

Decide what PM's actually improve or maintain machine's

health

Family physician model

7 of

Application to Machinery Healthcare

To get a complete picture of machine health, you need to run a number of tests.

And when that PM for overhaul (surgery) comes up, you can make an informed decision on whether to perform or defer it.

You’re more likely to catch something early.

8 of

Advantages of a Machine Centered Approach

Optimize Machines Healthcare

Defer routine overhauls

Collect complete data on each trip to machine

Less machines per day More valuable information

Manage failure

9 of

Machine Centered ProcessIt’s nothing new Reliability Centered Maintenance formalizes it

But the fact is not everyone can do RCM• They can’t afford it• They don’t have the manpower• They can’t get approval

But they still have to maintain the machine

10 of

Machine Centered Thought Process

What are the possible failures?

Which of these

failures are significant?

How can we avoid

these failures?

When we can't avoid failure, how

can we get an early warning?

Tailor a suite of tests to get

early warnings.

Collect all information at one

decision point.

11 of

System Identification

Motor Pump

VFD

12 of

First ask:

What are the possible failures

Think about the function of the machine

How can it fail to meet that function?

13 of

Function

Downstream (Load side)

Start motor

Stop motor

Deliver specified torque at specified RPM

Specified speed ramp rate up

Specified speed ramp rate down

accelerate load from stop to operating speed

adjust torque and speed on demand

Motor-Drive System Functions

14 of

Types of Failures

• Hidden

• Safety

• Environmental

• Operational

• Non-Operational

12/5/97 15 of

Functional Failure Analysis• Complete failure

• Partial failure

• Intermittent failure

• Failure over time

• Over performance of function

16 of

Function Functional Failure

Failure Mode

Start motor Motor will not turn winding failure (stator)

Insulation Failure (stator)

Rotor failure

Bearing Seized

Contactor Failed

Loss of Power

VFD Malfunction (Start)

Stop motor Motor will not stop Contactor Failed

VFD Malfunction (STOP)

Deliver specified torque at specified RPM

Motor turns at wrong speed.

VFD Malfunction (Speed control)

Motor fault

load fault

Specified speed ramp rate up

Motor ramps up at wrong rate

VFD Malfunction (ramp up)

winding failure (stator)

Insulation Failure (stator)

Rotor failure

Bearing Seized

Functional Failure of a Motor Drive System

17 of

Next ask:

Which of these failures are significant?

How often it happens - frequency

What’s the impact when it does - consequence

Risk = frequency times consequence

18 of

Machine History

Machine Failures Total Downtime

Casing failure 3 times in 10 years 24 hours

Seal failure Twice in the last six months

105 hours

NPSH failure Couple of times a week

Stops line for 10 minutes each time

Bearing failure About once a year 6 hours

• $10,000/hr downtime cost

• 2080 hours / yr

19 of

Calculations

• Pump Set 1:Total time = 10 yr x 2080 hr/yr = 20800 hrs

Downtime = 24 hrs

MTBF = 20800/3 = 6933.3 hrs

MTTR = 24/3 = 8 hrs

German

French

Cost = (3 fail x 8hr/fail x $10,000/hr)/10yr = $24,000/yr

20 of

Application Of Ranking

Machine MTBF MTTR Annual Downtime Cost

($)

Casing failure 6933.3 8 $24,000

Seal failure 520 52.5 $2,100,000

NPSH failure 20 0.16 $173,000

Bearing failure

2080 6 $60,000

Note that the 10 minute failure adds up to more loss than the 6 hr or 8 hr failures

21 of

Criticality Survey

Score Frequency Effect

1 1/10 yrs None

2 1/ yr A little

3 1/ month Some

4 1/ week A lot

5 1/ day Complete

22 of

Then ask:

How can we avoid these failures?

Design changes

Adjust, lubricate, …

Preventive replacement

23 of

Task Types

• Time directed

• Condition directed

• Failure finding

• Run to failure

• Regulatory compliance

24 of

Types of Preventative Maintenance Tasks

• Inspections• Visual Clues• Operating instructions

& emergency procedures

• Cleaning• Condition assessment

• Lubrication• Fasteners• Filters• PM for stored

equipment• Proactive Replacement

and Scheduled Refurbishment

25 of

When we can't avoid failure, ask:

How can we get an early warning?

Process parameters

Inspections

Technology

26 of

P-F Curve

27 of

Condition Assessment Techniques

• Process Parameters

• Vibration Analysis

• Infrared Thermography

• Ultrasonic

• Lubricating Oil Analysis

• 30+ Other NDT technologies

It’s a way of using information, not a specific technology

28 of

Then:

Tailor a suite of tests to get early warnings?

Only do the tests needed

29 of

Failure Mode Failure Causes Symptoms Measurement

winding failure (stator)

Conductor failure vibration > ips vibration monitoring

Various MCSA

Various MCE

excessive vibration vibration > ips vibration monitoring

Insulation Failure (Stator)

Breakdown Polarization index

R to gnd < ohms Megger

excessive current temperature > °F thermometer

amperes > A ammeter

voltage spike power quality monitor

excessive temperature Motor temperature > °F thermometer

Ambient temperature > °F thermometer

thermography

excessive vibration vibration > ips vibration monitoring

phase imbalance phase angle >± ° power quality monitor

MCSA

MCE

temperature > °F thermometer

Rotor failure broken rotor bars vibration > ips vibration monitoring

Bearing Seized Fatigue vibration > ips vibration monitoring

shock pulse > db Shock pulse meter

improper lubrication shock pulse > db Shock pulse meter

Lube deterioration lube monitoring

Motor Failure

30 of

Finally:

Collect all information at one decision point.

Most important step!

31 of

Machine Centered Thought Process

What are the possible failures?

Which of these

failures are significant?

How can we avoid

these failures?

When we can't avoid failure, how

can we get an early warning?

Tailor a suite of tests to get

early warnings?

Collect all information at one

decision point.

32 of

Optimize the Machines Healthcare