Xylem IM117 R01 5 and Larger Submersible Pump - Manual (Page 5)

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2.2 Assemble Pump End to Motor
Under no circumstance should the pump be run dry. Doing
so may damage internal parts. We suggest you check the
rotation on a three phase motor before assembling it to the
water end (pump). All 4" and 6" single phase motors should
rotate counterclockwise when viewed from the shaft end.
Rotation on three phase motors should match pump speci-
fications. Due to the high-starting torque the motor should
be secured in such a way as not to damage the motor but to
hold the motor from spinning.
Remove the cable guard from the pump (water end). Install
the motor shaft sand slinger if included with the water end in
the motor mounting hardware package. Attach the water end
to the motor. Align the wires in the cable guard and reinstall
it to the water end.
2.3 Install Check Valve(s)
Discharge heads are threaded with NPT pipe threads. All
models, without built-in check valves, require a spring
loaded check valve within 25' (7.5m) of the pump discharge
and below the drawdown level of the water supply. Motor
manufacturers recommend additional check valves every 200'
to 250' (70m) in the vertical discharge line. Check valves are
used to hold pressure in the system and to prevent backspin,
water hammer and upthrust.
Backspin is allowing water to flow back through the pump to
drain the system. It causes the impellers and motor rotor to
rotate in a reverse direction. This can cause premature thrust
bearing wear and if the motor starts during backspin the
shaft can be twisted or broken.
Water Hammer occurs when the lowest check valve is more
than 30' above the standing water level or the lower check
valve leaks and the check valve above holds. This creates a
partial vacuum (void) in the discharge piping. On the next
start, water moving at a very high velocity fills the void and
strikes the closed check valve and the stationary water in the
pipe above it, causing a hydraulic shock. This shock (water
hammer) can split pipes, break joints, and damage the pump
and motor. Water hammer is an easily detected noise. When
discovered the pump should be immediately shut down and
the installer contacted to resolve the problem.
Upthrust is an upward movement of the impellers and motor
shaft. It is caused by starting the pump at zero head due to
no check valve or a leaking check valve; or very low system
head due to a high static water level. Repeated upthrust can
cause premature failure of either or both the pump and the
motor. See 4.2
2.4 Installing Pump in Well
If you are using a torque arrestor, install it per the manufac-
turer’s installation instructions. On top feeding wells or large
diameter wells where water velocity will not cool the mo-
tor properly install a flow sleeve over the pump. See Table 3
– Required Cooling Flow.
Connect the discharge pipe to the pump discharge head.
Submersible pumps are capable of very high discharge pres-
sures, consult with your pipe supplier to determine the best
pipe material and schedule for each installation.
Lower the pump into the well. Set the pump at least 10' off
the bottom but above the screens. Protect the wires from
chafing on the well casing. Install a pitless adapter or similar
device at the wellhead. Consult the fitting manufacturer or
pitless supplier for specific installation instructions.
Using waterproof electrical tape, or wire ties, fasten the
wires to the drop pipe at 10' intervals. Make sure that the
tape does not loosen as it will block the pump suction if it
falls down the well.
2.5 Pressure Relief Valve
Pressure relief valves are mandatory (required) on any system
that is capable of producing over 100 psi or 230' TDH. In
an area where a water leak or blow-off may damage property
connect a drain line to the pressure relief valve. Run it to a
suitable drain or an area where the water will not damage
property.
2.6 Pressure Tank and Pressure Switch
(when used)
The pressure switch should be located at the tank cross tee
on a single tank and as close to the center as possible on
multiple tank installations. Multiple tank installations should
have a manifold pipe 1½ to 2 times the size of the supply
pipe from the pump. This is to reduce the friction head loss
or pressure differential in the manifold. Excessive losses
could cause switch chatter. There should be no filters, or
high loss fittings between the switch and the tank(s). Wide
open gate valves are allowed between the tank and switch.
2.7 Adjusting Tank Pre-Charge (when used)
Insure that the tank is empty of water. Use a high quality
pressure gauge to check the tank pre-charge pressure. The
pressure should be 2 psi below the pump cut-in (turn on)
pressure. As an example, a 30-50 psi system would use a
tank pre-charge of 28 psi.
Select an area where the temperature is above 34° F in which
to install the tank, pressure switch, and pressure relief valve.
The tank should be located in an area where a leak will not
damage property.
3.0 ELECTRICAL INSTRUCTIONS
3.1 General
Note: Do not power the unit or run the pump until all
electrical and plumbing connections are completed and the
pump is filled with water.
Always follow the National Electric Code (N.E.C.) in the
U.S., or the Canadian Electrical Code in Canada, as well as
all state, provincial, or local codes.
All electrical work must be performed by qualified
personnel. Some local laws require installation by only
“licensed installers”.
We suggest using only copper wire. Size wire from the charts
found in our ITT MAID, Motor Application & Installation
Manual, or an N.E.C.( National Electric Code) manual. If
discrepancies exist the N.E.C. in the U.S., and in Canada the
Canadian Electrical Code prevails.
3.0 ELECTRICAL INSTRUCTIONS