SPX Cooling Technologies 1200, 1000 manual Special Component Options, Fire Protection Options

/ Special Component Options /

Fire Protection Options

The PVC fill, louvers and drift eliminators used on Sigma towers are fire-retardant, having flame spread ratings less than 25 per ASTM E-84. Standard fan decking material

is pressure-treated fir plywood which ignites poorly and burns slowly. For these reasons, governing agencies (such as Factory Mutual) may not require fire protection sprinkler systems on Sigma towers.

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 and optional casing 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 are full-width, full-height of the tower interior (except cold water basin), and consist of pressure-treated fir plywood both sides of the column line between cells. Plywood thickness (and cost) vary according to the specified containment time.

•Steel construction. Remember that the Sigma series is available in steel construction – either galvanized or stainless – as are a number of other Marley series, all of which meet all established fire code requirements.

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 Sigma 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 on Marley cooling towers are TEFC, 1.0 or 1.15 service factor (appropriate to the applied load), 1800 RPM. Other enclosures (such as Explosion Proof) and motors specially wound for non-standard voltages are available at extra cost.

Two-speed motors are also available, and their advantages are discussed on page 22.

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