Specifications

Specifications
Specification Value
MH Fluid Cooler — Specifications: Options
20
selector switch shall be provided. Dry status
contacts wired to user terminal points indicat-
ing typical alarm and status events shall be
provided. Two safety circuits for the spray
pump, low water cut off preventing a dry run
pump and a pump shut down upon approach-
ing freezing temperatures in the cold water
basin shall be provided.
Available Options: Water level control with
various combinations of make-up, high alarm,
low alarm, high cut off and low cutoff events.
Basin heater controller with low water cutout.
Spray pump heat trace circuit. Power for
damper actuator motor. Circuit breaker feeder
for a remote mounted VFD.
Vibration Limit Switch:
6.5 Add the following paragraph in the
Mechanical Equipment section: A vibra-
tion limit switch in a NEMA 4 housing
shall be installed on the mechanical
equipment support for wiring to the shut-
down circuit of the fan motor starter or
VFD. The purpose of this switch will be to
interrupt control power voltage to a safety
circuit in the event of excessive vibration
causing the starter or VFD equipment to
de-energize the motor. It shall be adjust-
able for sensitivity, and include a means
to reset the switch.
Basin Heater:
11.2 Add the following paragraph in the Cold
Water Basin section: Provide a system
of electric immersion heaters and controls
for each cell of the fluid cooler to prevent
freezing of water in the collection basin
during periods of shutdown. The system
shall consist of one or more stainless
steel electric immersion heaters installed
in threaded couplings provided in the side
of the basin. A NEMA 4 enclosure shall
house a magnetic contactor to energize
heaters; a transformer to provide 24 volt
control circuit power; and a solid state cir-
cuit board for temperature and low water
cut-off. A control probe shall be located in
the basin to monitor water level and tem-
perature. Recirculating pump(s) shall be
fitted with heat trace cable and insulated.
The system shall be capable of maintain-
ing 40°F water temperature at an ambient
air temperature of _____ °F.
■ Unless specified otherwise, a Marley M-5 vibra-
tion switch will be provided. The requirement for
manual reset assures that the fluid cooler will
be visited to determine the cause of excessive
vibration.
■ The Marley basin heater components described at left represent our recommen-
dation 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 customarily 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 speci-
fications should be the lowest 1% level of winter
temperature prevalent at site.