SPX Cooling Technologies 92-1322C - Manual (Page 4)

4
/ Introduction /
The purpose of a basin heater is to prevent water freezing in the cooling
tower basin during periods of shutdown or standby operation. The heater
system is sized according to tower model and location to give maximum
protection against water freezing in the cold water basin. This heating
system is not intended to protect the tower fill and other components
from icing. Refer to Marley Technical Bulletin # H-002
"Operating Cooling
Towers in Freezing Weather." Contact your Marley Sales Representative
for a copy of this publication.
The Marley basin heater system is manufactured by INDEECO, a leader
in immersion heating equipment. The system is referred to as a "heater
package" and consists of immersion heaters, a control panel and combina-
tion temperature / liquid level sensor with a 12'-0" cable length. The basic
control panel contains a contactor(s) of sufficient capacity for the heater
elements selected. In addition the panel contains a transformer to reduce
line voltage to 24VAC for panel control power, and a solid state relay card
to detect low temperature and low water conditions. The panel enclosure
is rated NEMA 4X (liquid tight, noncorrosive) and the sensor cable is UL
outdoor rated. The sensor probe is stainless steel with
1 ⁄
2
" NPT threads
and a PVC bulkhead fitting for installation in the cold water basin.
The panel may control more than one heating element, up to its nameplate
KW rating for the voltage and phase stated. In addition to the components
of the basic panel described above, available options are fusing, circuit
breakers or disconnect switches. The circuit diagram located on the inside
of the panel cover will indicate the panel configuration.
Indicates presence of a hazard which can cause severe personal
injury, death or substantial property damage if ignored.
Indicates presence of a hazard which will or can cause personal injury
or property damage if ignored.
Indicates special instructions on installation, operation or maintenance
which are important but not related to personal injury hazards.
Warning
Caution
Note
The following defined terms are used throughout this manual to bring at-
tention to the presence of hazards of various risk levels, or to important
information concerning the life of the product.