17
Automatic Air Vent
There is an automatic air vent installed at the
high point of the system inside the pumping
package compartment. The air vent valve
must be in the proper position for operation.
Ensure that the small vent cap is loosened two
turns from the closed position, allowing air to
be vented from the system. It is advisable to
leave the cap on to prevent impurities from
entering the valve. See appendix for
additional information.
Dual Pumps
When redundant pumping is required, factory
installed dual pumps can be ordered. A dual
pump is a pump with two independent motors
and pumps in a single casing. This dual pump
has a swing split-flapper valve in the
discharge port to prevent liquid recirculation
when only one pump is operating. Isolation
valves in the casing allow one pump to be
isolated and removed for service while the
other pump is still operating.
The controls package will activate the pump
when the unit is given a run command. If the
controls do not recognize flow in 60 seconds,
the second pump will be activated and an
alarm signal will be generated. If the second
pump does not activate, the cooling will be
locked out. See appendix for additional
information.
Pressure Gauges and Thermometers
Pressure gauges and thermometers are
available as a factory installed option.
Thermometers are installed on the inlet and
outlet of the unit. One pressure gauge is
installed at each pump. This pressure gauge
is connected in three places to the water
piping before the suction guide/strainer, after
the suction guide and before the pump, and
after the pump. There is also a needle valve
at each of these points to isolate the pressure.
To measure the pressure at any given point,
open the needle valve at that point and close
the other two needle valves. One gauge is
used so that the calibration of the pressure
gauge is irrelevant in the calculation of the
differential pressure.
Pipe Insulation
The water piping and components on units
with pumping packages are not insulated at
the factory. Insulation should be installed on
the water piping after the system has been
checked for leaks.
Summary of Contents for LN Series
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