SPX Cooling Technologies Marley MC 7014H081 - 7014K121 - Manual (Page 23)

Specifications Specification Value
Marley / MC Fluid Cooler / Specifications: Options
23
temperature at the coil and the other
for set point. Process temperature input
shall be obtained using a thermal sens-
ing device on the process coil and wired
back to the solid state temperature
controller in the control panel. Staging
of multiple motors and speeds will be
accomplished with an integral PLC.
Vibration Limit Switch:
6.5 Add the following paragraph in the
Mechanical Equipment section: A
single-pole, double-throw vibration
limit switch in a IP55 housing shall be
installed on the mechanical equipment
support for wiring into the owner’s
control panel. The purpose of this
switch will be to interrupt power to the
motor in the event of excessive vibra-
tion. It shall be adjustable for sensitiv-
ity, and shall require manual reset.
Basin Heater:
11.2 Add the following paragraph in the
Cold Water Basin section: Provide
an electric immersion heater for each
cell of the fluid cooler to prevent freez-
ing of water in the collection basin
during periods of shutdown. The rod
type heater is installed in the side of
the cold water basin. Each heater will
include an integral thermostat, set
point nominally 4°C but adjustable to
suit local operating requirements.
Fan Motor Variable Speed Drive:
Marley All Weather ACH550 System
6.4 Add the following paragraph in the
Mechanical Equipment section when
VFD is used with customers Building
Management System: A complete UL
listed Variable Speed Drive system in a
IP10 indoor, IP52 indoor or IP14 outdoor
enclosure shall be provided. The VFD
shall use PWM technology with IGBT
switching and integrated bypass design.
VFD out put switching shall not cause
mechanical issues with gearbox teeth
or drive shafts. The VFD shall catch a fan
spinning in the reverse direction without
tripping. The panel shall include a main
disconnect with short circuit protection
and external operating handle, lockable
■ Unless specified otherwise, a Fire
Fighting Enterprises switch will be provid-
ed. A double-pole, double-throw model
is also available. The requirement for
manual reset assures that the fluid cooler
will be visited to determine the cause of
excess vibration.
■ The Marley basin heater components described at left represent our
recommendation for a reliable automatic system for the prevention of
basin freezing. They are normally shipped separately for installation at
the jobsite by the installing contractor. When purchased in conjunction
with the enhanced Control System option, however, they are customar-
ily factory-mounted and tested.
Submerged in basin water, in which zinc ions are present, copper
immersion heaters must not be used. Insist upon stainless steel.
The ambient air temperature that you insert in the specifications
should be the lowest 1% level of winter temperature prevalent at site.
■ Marley VFD drive systems are designed to combine absolute tem-
perature control with ideal energy management. The fluid cooler user
selects a cold water temperature and the drive system will vary the
fan speed to maintain that temperature. Precise temperature control
is accomplished with far less stress to the mechanical equipment
components. The improved energy management provides fast pay-
back.
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