Specifications
Marley
/
MD Cooling Tower
/
Specifications: Options
35
Specification Value
Control Options
Fan Motor Starter Control Panel:
6.4 Add the following paragraph in
the Mechanical Equipment sec-
tion: Each cell of the cooling tower
shall be equipped with a UL listed
control system in a IP52 or IP56 out-
door enclosure capable of controlling
single-speed or two-speed motors as
required, and designed specifically for
cooling tower applications. The panel
shall include a main fused discon-
nect or main circuit breaker with an
external operating handle, lockable in
the off position for safety. Across-the-
line magnetic starters or solid-state
soft-start starters as required shall
be controlled with a thermostatic or
solid-state temperature controller.
Door mounted selector switches shall
be provided to enable automatic or
manual control and wired to meet local
control voltage. If required, control cir-
cuit to be wired out to terminal blocks
for field connection to a remote vibra-
tion switch, overload trip alarms and
remote temperature control devices.
The temperature controller shall be
adjustable for the required cold-water
temperature. If a thermostatic control-
ler is used it shall be mounted on the
side of the tower with the temperature
sensing bulb installed in the cold water
basin using a suspension mounting
bracket. If a solid-state temperature
controller is used the controller will be
door mounted on the control panel.
The temperature controller will display
two temperatures, one for outgoing
water and the other for set point.
Water temperature input shall be
obtainedusingathree-wireRTDwith
dry well in the outlet water piping and
wired back to the solid-state tempera-
ture controller in the control panel.
■ If it is your opinion that the control system for the cooling tower
be part of the cooling tower manufacturer’s responsibility, we are
in wholehearted agreement with you. Who better to determine the
most efficient mode and manner of a cooling tower’s operation—
and to apply a system most compatible with it—than the designer
and manufacturer of the cooling tower?
Marley variable speed drives are also available for the ultimate in
temperature control, energy management, and mechanical equip-
ment longevity.
