Xylem 19 001 251 R3 Floboy VFD Pumping System - Manual (Page 19)

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Figure 9: Confirm rotation by making sure motor is
operating in the direction of the motor tag
SYSTEM PRESSURIZATION
With the system isolation valve on the discharge of
the pump station almost fully closed, turn the
Off/On switch to the "On" position. When the pump
starts, you should notice an immediate increase in
pressure on the manifold pressure gauge. If the
pressure does not rise to at least the operating
pressure of the system, turn the Off/On switch to
"Off" and repeat the priming process described
earlier. Otherwise refer to the "Troubleshooting"
section of this manual or contact the factory for
assistance.
CAUTION
If you open the system isolation valve too
quickly, the pump may instantly lose prime and
will require repeating the priming process.
Leave the station isolation valve in a slightly
cracked state until you are certain water is flowing
into the discharge piping. On irrigation systems it
is a good idea to open several sprinklers at the
remote end of the system. When water begins to
emerge from these heads the system is
reasonably full and the pump station isolation
valve can be gradually opened to its full position.
When starting a centrifugal pump for the first time
it is a good practice to stay close to the pump for
the first few minutes of operation. If you notice
conditions such as smoke from the motor, unusual
odor, loud noises, etc., turn the pump off
immediately and consult the factory. In some
cases the pump may sound like it is pumping
marbles or rocks. This noise may be the sign of
mechanical problems or it may be a hydraulic
phenomenon known as cavitation occurring inside
pump. Cavitation is a condition that may
permanently damage the pump if allowed to
continue. It is usually caused by improper suction
installation or by over demanding the pump. It is
not uncommon to experience cavitation when
filling the discharge piping since empty piping
encourages pump over demand if the station
isolation valve is opened too far or too quickly.
Should you notice this sound, gradually close the
isolation valve until the noise intensity subsides.
Once the system approaches full design pressure,
the cavitation noise should disappear. If throttling
the system isolation valve makes no difference in
the noise intensity, turn the pump off and consult
the factory.
PRIMING LINE ADJUSTMENT
On pumping systems requiring a foot valve in the
suction, a priming line valve is used to apply a
seating pressure to the suction pipe when the
pump is not operational. This valve is set for 30 psi
but can be adjusted if so desired. Turn the valve
adjustment screw clockwise to increase pressure
and counterclockwise to decrease.
OVERLOAD TRIP ADJUSTMENT
Every motor starter assembly uses an electronic
sensor that monitors the motor current. If the
current exceeds a safe limit, considered to be a
point where the motor is overloaded, the sensor
shuts the motor off. The current limit is factory
preset but can be adjusted as noted by the
calibrated scale along side the adjustment screw.
CAUTION
This adjustment should be made by a qualified
technician only. Improper adjustment of this
setting can jeopardize motor lifetime and affect
system warranty.
The overload should never be adjusted above the
motor's full load rating. This rating is stamped on a
motor identification tag fixed to the motor housing.
Make certain the motor full load current rating
corresponds to the correct operating voltage since
multiple voltages and their corresponding current
ratings may be noted on the same tag.