20
W W W . B A L T I M O R E A I R C O I L . C O M . A U
M A R 2 1 0 - 2
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.
Water Level Control
There are two types of water level controls used on BAC cooling towers:
• Mechanical make-up valve assembly
• Optional electric water level control package
Mechanical Make-up Valve Assembly
A oat-operated mechanical water make-up assembly is furnished
as standard equipment on the cooling tower. The standard make-up
assembly consists of a corrosion resistant make-up valve connected to
a oat arm assembly actuated by a polystyrene-lled plastic oat. The
oat 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 oat 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 100 and
350 kPa for proper operation. BAC recommends a surge protector
(provided by others) for pressures over 350 kPa.
• 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 operating level.
• With the design thermal load and the average water pressure (100
to 350 kPa) 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 specied,
readjust the oat 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 rst 24 hours of operation.
• Operating at the recommended water level will ensure that the unit
basin contains sufcient water volume to prevent air entrainment in
the circulating pump during system start-up and provides sufcient
excess basin capacity to accept the total system pulldown volume.