AAON LZ Series, Установка, эксплуатация и обслуживание

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Pump Operation
Before initial start of the pump, check as
follows:
1.
Be sure that pump operates in the
direction indicated by the arrow on the
pump casing. Check rotation each time
motor leads have been disconnected.
2.
Check all connections of motor and
starting device with wiring diagram.
Check voltage, phase and frequency of
line circuit with motor name plate.
3.
Check suction and discharge piping and
pressure gauges for proper operation.
4.
Turn rotating element by hand to assure
that it rotates freely.
Running
Periodically inspect pump while running, but
especially after initial start-up and after
repairs.
1.
Check pump and piping for leaks. Repair
immediately.
2.
Record pressure gauge readings for future
reference.
3.
Record voltage, amperage per phase, and
kW.
Condenser Fan Motors
The direct drive condenser motors on AAON
evaporative-condensed chillers are 1200 rpm
premium efficiency motors controlled by a
VFD. These motors are totally enclosed air
over motors with weep holes in the bottom
end bell so that any condensation can drain
out of the motor.
The motors have a small electric resistance
heater installed inside the casing to keep the
motors warm when they are deactivated. The
heaters are designed to keep the interior of the
motor 10°F warmer than the surrounding
ambient
temperature. This prevents
condensation from forming inside the motor.
Ensure that fan is tightly mounted to the
motor shaft and the motor mounting bolts are
aligned and secure.
Water Make Up Valve
The sump water level is controlled by a set of
conductivity probes at different levels in the
sump. The standard sump water level is
15 inches deep. This water level controller is
located in the vestibule behind the condenser
pump. There are four conductivity probes in
this controller. There is a reference probe
(shown as “ref” on the wiring diagram). This
probe is one of the two longest probes. The
other long probe is the low water level probe
(shown as “lo” on the wiring diagram). The
medium length probe is for the medium water
level (shown as “med” on the wiring
diagram). The short probe is for the high
water level (shown as “hi” on the wiring
diagram). There is a solenoid valve in the
makeup water line that is activated by the
water level controller. The water level
controller determines the level of water in the
sump based on conductivity between two
probes. If the controller sees conductivity
between two probes, it knows that water is at
least at the level of that probe.
If the water in the sump is below the low
probe, it will not allow the condenser pump
or the sump heater to operate. It will activate
the makeup water solenoid to try to fill the
sump assuming water is flowing to the unit.
Once water is above the low probe, it will
allow the condenser pump and sump heater
(if ordered and the ambient temperature is
below 40°F) to operate. The makeup water
solenoid will remain activated until water
gets to the high water level. The makeup
water solenoid will deactivate until water