Air Purity
The cabinet should not be installed in an area where the air may be contaminated with any of the following:
●Excessive dust, lint, carbon particles, paper fiber contaminants, or metallic contaminants
● Contaminants expelled by office copying machines
●Highly corrosive atmosphere within an enclosed area or atmosphere containing
vaporized chemical compounds that may condense on the equipment
●Explosive or flammable atmosphere
Lighting
I.ighting should be adequate to allow administration and maintenance personnel to perform their tasks. The recommended light intensity level is 50 to 70 footcandles. This level complies with the Occupational Safety and Health Act (OSHA) standards.
Electrical Noise (RFI)
In most cases, electrical noise is introduced to the system through trunk or voice terminal cables. However, electromagnetic fields near the system cabinets may also induce noise in the system. Therefore, the system cabinets and cable runs should not be placed in areas where a high electromagnetic field strength exists. Radio transmitters (AM or FM), television stations, induction heaters, motors (with commutators) of 0.25 horsepower (200 watts) or greater, and similar equipment are leading causes of interference. Small tools with universal motors are generally not a problem when they operate on separate power lines. Motors without commutators generally do not cause interference.
Field strengths below 1.0 volt per meter are unlikely to cause interference. Field strength can be measured by a tunable meter such as the Model
The field strength produced by radio transmitters can be estimated by dividing the square root of the emitted power in kilowatts by the distance from the antenna in kilometers. This yields the approximate field strength in volts per meter and is relatively accurate for distances greater than about half a wavelength (150 meters for a frequency of 1000 KHz).
* Trademark of Holaday Industries
