SPX Cooling Technologies SS-NC-08A Specifications, Specification Value, Fan Cylinder Extensions

Marley / NC Class Stainless CoolingTower / Specifications: Options 18

Specifications Specification Value

shall be operated as a stand- alone sys- tem without the need for a BMS system. Operator controls shall be mounted

on the front of the enclosure and shall consist of start and stop control, bypass/ VFD selector switch, Auto/Manual selector switch, manual speed control, and solid-state temperature controller. An emergency bypass selector switch internal to the panel allowing the cooling tower fan motor to be run at full speed shall be furnished. To prevent heating problems in the cooling tower fan motor and to assure proper gear box lubrication the VFD system shall de energize the motor once 25% motor speed is reached and cooling is no longer required. The VFD shall include de-icing logic with auto canceling and adjustable time. Speed

in De-Ice mode shall not exceed 50 % motor speed. The cooling tower manu- facturer shall supply VFD start-up assis- tance. Tower vibration testing throughout the speed range is required to identify and lockout any natural frequency vibra- tion levels which may exceed CTI guide- lines.

Miscellaneous Options

Motor out of the Airstream:

6.1Add the following to the end of this paragraph: The motor shall be mount- ed outside the casing of the tower, and shall be connected to the gear reducer by a dynamically-balanced, stainless steel tube and flange driveshaft.

Fan Cylinder Extensions:

9.1Insert the following after the first sentence: Fan cylinder extensions shall be provided to elevate the fan dis- charge to a height of ___ m above the fan deck level.

■For many years, a feature of Marley cooling towers was that the electric motors were located outside the fan cylinders, where they were easily accessible, and where they were not subjected to the constant humidity that exists inside the tower plenum.

Although improved motor designs (insulation, bearings, seals, and lubricants) have now made it fea-

sible for us to locate the motor inside the tower in close-coupled prox- imity to the Geareducer® (page 7), many users still prefer the motor to be located outside the humid airstream. If you are among those users— or are among those who see the wisdom of their thinking—please spec- ify this option. If you do, however, please require it of all bidders.

■Extensions are available in 305mm increments to a maximum height equal to the diameter of the fan. Such extensions may be considered necessary in order to elevate the discharge beyond the bounds of an enclosure. Discuss applicability with your local Marley sales representa- tive.