Water Level Control - BAC FXV-0806-12D Series Operation & Maintenance Manual

Water Level Control

There are two types of water level controls used on BAC cooling units:
• Mechanical make-up valve assembly
• Optional electric water level control package
Mechanical Make-up Valve Assembly
A float-operated mechanical water make-up assembly is furnished as standard equipment
on the unit. The standard make-up assembly consists of a corrosion resistant make-up
valve connected to a float arm assembly actuated by a polystyrene-filled plastic float. The
float is mounted on an all-thread rod held in place by wing nuts. The cold water basin
operating water level can be adjusted by repositioning the float and all-thread rod using
the wing nuts provided.
• Inspect the make-up valve assembly monthly and adjust if necessary.
• Inspect the valve annually for leakage. Replace the valve seat if necessary.
• Maintain the make-up water supply pressure between 15 psig and 50 psig for proper
operation. BAC recommends a surge protector (provided by others) for pressures over
50 psig.
• Set the initial basin water level by adjusting the wing nuts, so that the make-up valve
is completely closed when the water level in the cold water basin is at the overflow
connection.
• With the design thermal load and the average water pressure (15 to 50 psig) at the
valve, the above setting will produce operating water levels as stated in Table 1 on
Page 10.
• If the thermal load is less than the design load at the time of unit start-up, the
procedure may produce operating levels greater than those shown in Table 1. If
operating levels are higher than specified, readjust the float in order to attain the
recommended operating level.
• Closely monitor the water level in the cold water basin and adjust the level if necessary
during the first 24 hours of operation.
• Operating at the recommended water level will ensure that the unit basin contains
sufficient water volume to prevent air entrainment in the circulating pump during
system start-up and provides sufficient excess basin capacity to accept the total
system pull-down volume.
Detailed Component
Maintenance
Procedures
Water Level Control
Mechanical Make-up Valve
Assembly
Optional Electric Water Level
Control Package
NOTE: If the unit has been ordered
with the optional electric water
level control package or is intended
for remote sump application, a
mechanical water make-up valve
will not be provided.
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