Balancing IQ - Ludeca

Created on March 04, 2022 By

Rick Potratz

Balancing IQ Part One

1 / 5

A technical definition for a balanced rotor is:

Where the center of mass is close to the same as the axis of rotation

When the nickel will stand on end when placed on the bearing housing of the running rotor

When a rotor’s geometric rotational centerline and mass centerline coincide

When I can no longer feel vibration

None of the above

2 / 5

Which ISO balance grade tolerance is the tightest?

ISO balancing Grade 16

ISO balancing Grade 6

ISO balancing Grade 2.5

ISO balancing Grade 0.4

None of the above

3 / 5

Every rotor will have some residual unbalance because

Nothing is ever perfectly balanced

All balancing instruments have limitations in their accuracy

Both A and B

None of the above

4 / 5

Trial weights:

Are used to calculate a balancing coefficient

Are placed on a rotor until the balance specification is met

Are only used in field balancing

Are always removed from the rotor

5 / 5

Imbalance will primarily affect which frequency?

1x rotational speed

2x rotational speed

Both A and B

None of the above

Your score is

The average score is 66%

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Created on March 04, 2022 By

Rick Potratz

Balancing IQ Part Two

1 / 5

Which of the following conditions does not result in the unbalance?

Uneven dirt accumulation on a fan

Lack of homogeneity in materials, especially in castings (e.g. bubbles, porous sections, blow-hole)

Eccentric rotor

Cracked rotor

Rotor deflection (e.g. paper mill rolls)

A missing balance weight

A loose foot

2 / 5

In order to correct dynamic unbalance

3 weights are always required

4 weights are always required

A two-plane balance setup is best

A single-plane balance setup is best

3 / 5

Every rotor will have some residual unbalance because

Nothing is ever perfectly balanced

All balancing instruments have limitations in their accuracy

Both A and B

None of the above

4 / 5

Machinery resonance:

Has no effect on balancing

Has a small effect, but the analyzer will correct for it

Will allow you to achieve a better grade of balance due to the amplification factor of resonance

Will make your phase unsteady and render it difficult to nearly impossible to balance within a resonance

5 / 5

An out-of-balance condition is likely to cause:

Damage to bearings

Damage to seals

Deterioration of the overall condition of the machine

All of the above

Your score is

The average score is 84%

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Created on March 04, 2022 By

Rick Potratz

Balancing IQ Part Three

1 / 5

If we increase the speed of a rotor by 2x, the vibration related to imbalance should increase by:

16x

2 / 5

A time-synchronous averaging filter is not as accurate as an analog filter set to sharp

True

False

3 / 5

Balancing using fixed locations refers to:

Fans which are always located in the same geographical position

Balancing with a fixed amount of weight

Balancing using a fan’s blades or a symmetrical bolt pattern for weight locations

Rotor balancing using permanently installed balancing stands

4 / 5

Precision balancing is more important for high-speed machinery than low-speed machinery

True

False

5 / 5

An out-of-balance condition is likely to cause:

Damage to bearings

Damage to seals

Deterioration of the overall condition of the machine

All of the above

Your score is

The average score is 78%

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