SPX Cooling Technologies 160 manual Available Options, Cell Partition Options, Fire Safety Options

/ Available Options /

■Cell Partition Options

Every Class 160 tower includes plenum partitions and hot water distribution basin partitions between adjacent cells. Plenum partitions keep air from entering an operating cell through an adjacent idle fan—assuring consistent thermal performance. Basin partitions let you inspect and clean individual basins while the rest of the tower continues to operate.

Specify extra partitions carefully because excess partitions can sometimes discourage routine maintenance and good housekeeping procedures. Two options are available to meet specific design goals:

❑Fill area partitions are available, but usually not necessary.

The solid sheet design of film fill prevents water and air migration between the fill areas of adjacent cells in all operating modes.

❑Complete watertight partitions let you use adjacent cells to serve separate loads having incompatible system temperatures. Watertight partitions consist of exterior grade, pressure-treated fir plywood, sealed to cold water basin partitions made from the same material as the basin sides. For concrete basin partitions, Marley drawings specify the appropriate design dimensions.

Optional weir gates in wood basin partitions let you mix or segregate the water in the basin to meet your operating needs.

■Cold Water Collection Basins

If you plan to locate your tower above grade, we can supply a treated Douglas fir cold water collection basin, complete with the necessary operating accessories. The basin floor is exterior grade, pressure-treated fir plywood, supported on joists.

Basin sides are also plywood, machined to fit the basin floor, providing a watertight joint after sealing.

The standard wood basin includes at least one or more depressed, side-outlet sumps, complete with plugged drains and hot dip galvanized or stainless steel debris screens. Standard sumps are FRP construction or galvanized steel depending on outlet size.

Each basin includes an overflow/cleanout connection consisting of a galvanized full coupling and normally-installed standpipe which removes easily for flush-out basin cleaning.

A float operated, mechanical makeup valve automatically replenishes water lost from the system. The valve is located in

the plenum chamber between fill banks, just inside the endwall access door to facilitate adjustment and maintenance.

■Fire Safety Options

On specific jobs you may want to weigh the cost of various modifications against the cost (and maintenance) of a sprinkler system—or the cost of higher insurance premiums. One or more of the following tower modifications may negate the need for a sprinkler system:

❑Fire-retardant fan cylinders offer flame spread less than 25 per ASTM E-84.

❑A ¹⁄₄″ thick fiber-reinforced cement board (FRC) overlay on the fan deck acts as a fire stop and provides a nonskid walking surface.

❑A ¹⁄₄″ FRC overlay on the distribution basin covers acts as a fire stop.

❑Barrier walls keep fire from spreading between cells in multicell towers. Specify barrier wall design by containment period, such as a “20-minute fire wall”. Barrier walls consist of pressure-treated fir plywood between cells. Plywood thickness (and cost) vary according to the specified containment time.

❑FRP casing having a flame spread rating of 25 or less.

If your insurance carrier insists on a sprinkler system for your tower, consult your Marley sales representative. We can provide a sprinkler system to fit your needs, or work with your people to be sure that the sprinkler system and tower will meet your specification.

■Non-Standard Motors

Although you can buy your Class 160 tower “less motor” at a cost reduction, it is not normally recommended. Motors supplied on Marley towers meet rigorous specifications developed from environmental chamber tests at our Development Center. These specifications represent prudent minimum design requirements.

Unless otherwise specified, motors provided are TEFC,

1.15service factor (appropriate to the applied load), 1800 RPM. Other enclosures (such as Explosion Proof) and motors specially wound for nonstandard voltages are available at extra cost.

Two-speed motors are also available, and their advantages are discussed on page 6.

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