A Practical Guide to Maximizing Machine Uptime

Every day, maintenance professionals across the world face the challenge of pushing

maximum machine potential while at the same time, keeping repairs at a minimum – a

challenge that is difficult to accomplish. Thankfully, there is a solution that opens the

door to reliability – predictive maintenance technology.

very day, maintenance professionals across the world face the challenge to maintain maximum

machine uptime while reducing costly downtime – a challenge that is difficult to accomplish.

Predictive maintenance programs can accomplish this predicament with low investment

requirements. Predictive maintenance services help determine the condition of in-service

equipment in order to predict when maintenance should be performed. This approach offers

savings over routine maintenance since tasks are only performed when needed. The main value

of predictive maintenance is to allow the convenience of scheduling corrective maintenance

ahead of time. Additionally, this allows one to prevent unexpected equipment failures. Benefits

may include:

Increased equipment lifetime

Increased plant safety

Optimized spare parts handling

Lower maintenance costs

Reduced machinery downtime

Increased production

There are three types of machinery maintenance:

1. Reactive

2. Preventative

3. Predictive

Reactive maintenance is really no maintenance at all – run your equipment until you experience

a total failure. The problem with this technique is that failures are often untimely and more

expensive to deal with. Not to mention, some failures can result in a complete disaster to your

business. That’s where preventative maintenance comes in.

Preventative maintenance involves periodic disassembly, full inspection and replacement of

worn parts to prevent a future disaster from occurring. By doing so, you’ll experience a lower

frequency in breakdown repairs and shutdowns. Furthermore, this leads into predictive

maintenance which involves the trending and analysis of a machine’s current condition to

detect and identify developing problems before experiencing equipment failure.

Predictive programs help get the maximum performance out of a machine before end of life. By

monitoring and diagnosing problems ahead of time, you can significantly increase the life and

productivity of your equipment before a catastrophic failure may occur.

E

The ultimate goal of predictive maintenance is to perform maintenance

at a scheduled point in time when the maintenance activity is most

cost-effective; prior to performance loss. The “predictive” component

derives from the goal of predicting the future trend of the equipment’s

condition. In order to achieve maximum productivity and minimize

disruption of normal operations, predictive maintenance inspections

are performed while equipment is in use.

An integral part of predictive maintenance is analysis and reporting. It’s

important to be able to track equipment performance factors to fully

utilize predictive maintenance for what it’s worth.

Predictive Maintenance Technologies

To evaluate equipment condition, predictive maintenance utilizes non-

destructive testing technologies such as:

Infrared Thermography

Oil Analysis

Vibration Analysis

Dry-ice Blasting

Motor Circuit Testing

Infrared Thermography

Infrared monitoring and analysis can be used from low-speed equipment to high-speed

equipment, and can be effective for spotting both electrical and mechanical failures.

Oftentimes, infrared has been said to be the most cost-effective technology available. Infrared

technology can be defined as the process of generating visual images that represent variations

of IR radiance of surfaces of objects. IR radiation falls outside that of visible light and therefore,

it’s invisible to the naked eye. However, an IR camera or similar device allows us to escape the

visible light spectrum and view an object based on temperature. Why is this important? Similar

to other predictive maintenance technologies, IR attempts to detect the presence of stressors

or conditions that will decrease the life of your equipment.

Predictive Maintenance

Services Offered through

ACT/Whelco:

Turnkey services

Vibration Analysis

Motor Circuit Testing

Online Analyzer

Laser Alignment

Coupling Inspections

Belt Tensioning

Field Balancing

Cryogenic Dry Ice

Cleaning

On-sit Winding

Analysis

DC Brush

Maintenance

Oil Sampling

Infrared

Thermography

On-site

Installation/Removal

Bearing Replacement-

Sleeve and Rolling

Elements

For example, rotating equipment problems are normally the result of frictional changes that

can be detected in the thermal profile. The following list contains just a few of the possible

:

Transmission lines

Splices

Shoes/end bells

Inductive heating

problems

Insulators

Cracked or

damaged/tracking

Distribution lines/systems

Splices

Line clamps

Disconnects

Oil switches/breakers

Capacitors

Pole-mounted

transformers

Lightning arrestors

Imbalances

Substations

Disconnects, cutouts, air

switches

Oil-illed switches/breakers

(external and internal

faults)

Capacitors

Transformers

Internal problems

Bushings

Oil levels

Cooling tubes

Lightning arrestors

Bus connections

Generator Facilities

Generator

Bearings

Brushes

Windings

Coolant/oil lines: blockage

Motors

Connections

Winding/cooling patterns

Motor Control Center

Imbalances

In-Plant Electrical Systems

Switchgear

Bus

Cable trays

Batteries and charging

circuits

Power/Lighting

distribution panels

The following list provides a few examples:

Steam Systems

Environmental

Boilers

Water discharge patterns

Refractory

Air discharge patterns

Tubes

Motors and rotating

equipment

Traps

Bearings

Valves

Mechanical failure

Lines

Improper lubrication

Heaters and furnaces

Coupling and alignment

problems

Refractory inspections

Electrical connections on

motors

Tube restrictions

Air cooling of motors

Fluids

Vessel levels

Pipeline blockages

Oil Analysis

One of the oldest predictive maintenance technologies still used today is that of oil analysis. Oil

analysis is used to define three basic machine conditions related to the lubrication system:

1. The condition of the oil – test the viscosity, acidity, etc.

2. The condition of the lubrication system – test for water content, silicon, or other

contaminants

3. The condition of the machine itself – analyze wear particles existing in the lubricant

Taking samples from your active, low-pressure line ahead of any filtration devices is a good way

to indicate the condition of the oil, lubrication system and machine. For consistent results and

accurate trending, be sure to take samples from the same place in the system each and every

time. A full analysis will help determine the condition of the lubricant, excessive wearing of oil-

wetted parts and the presence of contamination.

Vibration Analysis

Abnormal levels of vibration can cause equipment failure without proper analysis. Vibration, as

defined in the dictionary – “a periodic motion of the particles of an elastic body or medium in

alternately opposite directions from the position of equilibrium when that equilibrium has been

disturbed or the state of being vibrated or in vibratory motion as in oscillation or a quivering or

trembling motion.”

The important factor in this definition is that vibration is motion. As this motion continues to

build up, the level of frequency can change and is undetectable by human touch. In order to

obtain valuable data about equipment vibration, we use vibration detection instruments and

signature analysis software. We use sensors to quantify the magnitude of vibration and convey

them in the following three ways:

1. Displacement

2. Velocity

3. Acceleration

With a good understanding of machine design and operation, we can interpret the information

received from testing to define the machine’s problem. Once the information is retrieved, an

easy-to-follow report is generated for anyone with basic knowledge to read.

Vibration monitoring and analysis can be performed on these types of equipment:

Unbalance

Eccentric rotors

Misalignment

Resonance problems

Mechanical

looseness/weakness

Rotor rub

Sleeve-bearing problems

Rolling element bearing

problems

Flow-induced vibration

problems

Gear problems

Electrical problems

Belt drive problems

Analyzing this equipment to determine the presence of bad vibration is not a simple task.

Properly performed and evaluated tests require highly trained and skilled individuals.

Dry-ice blasting

Dry-ice blasting is a form of abrasive blasting where dry ice is accelerated in a pressurized air

stream and directed at a surface in order

to clean it. Why use dry-ice? Dry-ice

leaves no chemical residue as it

sublimates at room temperature.

Essentially, the sublimation process

absorbs a large portion of heat from the

surface which produces shear stress due

to thermal shock. This is claimed to

improve cleaning as the top layer of dirt is

expected to transfer heat and flake off

very easily.

Dry ice cleaning removes the following:

Paint/varnish

Oil

Grease

Tar

Bitumen

Dirt

Ink

Resin

Adhesives

Wax

Binders and solvents

Silicon/rubber residues

Chewing gum

Graffiti

…And much more

Motor Circuit Testing

If you’re looking for a full analysis of your motor condition, infrared and vibration will not

provide all the answers required to properly diagnose the condition of your motor. Over time,

motor circuit testing techniques have become more and more sophisticated. Motor faults such

as winding short-circuits, improper torque settings, open coils, etc. can be easily evaluated with

professional motor circuit testing. Motor analysis equipment remains fairly expensive and

requires a degree of skill and technique. There are two commonly used tests:

1.) Electrical Surge Comparison

a. One of the primary concerns of motor condition is winding insulation. Surge

comparison testing can be used to properly identify turn-to-turn and phase-to-

phase insulation deterioration. Due to differences in insulation thickness, motor

winding insulation tends to be more susceptible to failure from stress. Surge

comparison testing allows us to quickly identify where the deterioration exists by

applying a high frequency transient surge to the winding and compare the

resulting voltage waveforms. When differences in waveforms exist, this indicates

insulation or coil deterioration.

2.) Motor Current Signature Analysis

a. Another worthwhile tool in motor circuit testing is motor current signature

analysis (MCSA). The benefit of MCSA is that it uses a non-intrusive method for

detecting mechanical and electrical problems. The technology is based on the

idea that a conventional electric

motor driving a mechanical load

acts as a transducer. The motor

senses the mechanical load

variations and then converts them

into an electrical current that

moves along the motor power

cables. These particular currents

are reflective of a machine’s

condition.

Motor Circuit Testing Applications:

Stem packing degradation

Incorrect torque switch

settings

Degraded stem

Worn gear tooth wear

Restricted valve stem

travel

Improper seal installation

Inaccurate shaft alignment

or rotor balancing

Improper bearing or gear

installation

Obstructions in the valve

seat area

Disengagement of the

motor pinion gear

Insulation deterioration

Turn-to-turn shorting

Phase-to-phase shorting

Reversed or open coils

Short circuit

Conclusion

As with most predictive maintenance services, the greatest saving opportunity does not come

from preventing a catastrophic failure, but rather the less tangible cost savings benefits. It’s

important to understand that one, unplanned motor failure can cost more than one year of

predictive maintenance services. Reduced downtimes, increased productivity, ability to

schedule maintenance, decreased inventory cost and decreased overtime are just a few of the

advantages of predictive maintenance services.

ACT is first and foremost a service company. We measure our

business and success every day on three variables: the quality of

our work, our turnaround time, and cost-effective pricing. Our

team takes pride in providing excellent customer service to our

customers. We understand we are only as good as the service

we provide TODAY. When we build a relationship with our

customers, we consider it a partnership. Consider ACT when

looking for a partner to assist with you industrial repair needs.

When your motor or equipment fails, your line goes down and

you are losing money, you need a trusted partner who is

experienced, diverse and able to address your needs on your

schedule. Whether your situation involves critical production

downtime and/or a unique technology or process, Whelco is the

shoulder you can lean on.

For a FREE evaluation and quote on your equipment, contact us via one of the methods

below:

Phone: 888-655-3955

Email: sales@act-repair.com

Fax: 419-873-6575