FIG. 6.6.3 Reducing friction of rotating and sliding parts to decrease noise radiation.

(a) Static Unbalance (b) Dynamic Unbalance

Black blocks are heavy parts of rotor that cause vibration. ^^ White blocks are locations where counterweights must be placed to eliminate the vibration.

FIG. 6.6.4 Effects of static and dynamic unbalance on rotor operation.

dB, or roughly one-quarter to one-half of the original loudness. Air speeds less than 3 m/s measured at a supply or return grille produce a level of noise that usually is unnoticeable in residential or office areas. To reduce air speed in a given system operate lower motor or blower speeds, install more ventilating grilles, or increase the cross-sectional area of the existing grilles.

DIY Battery Repair

DIY Battery Repair

You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.

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