Piping; Wiring And Grounding; Selecting And Wiring Pump Control Panels And Switches - Xylem Bell & Gossett Single Phase Instrucciones De Instalación, Operación Y Mantenimiento

PIPING

Discharge piping should be no smaller than the pump
discharge diameter and kept as short as possible, avoiding
unnecessary fittings to minimize friction losses.
Install an adequately sized check valve matched to the
solids handling capability of the pump to prevent fluid
backflow. Backflow can allow the pump to "turbine" back-
wards and may cause premature seal and/or bearing wear.
If the pump is turning backwards when it is called on to
start the increased torque may cause damage to the pump
motor and/or motor shaft and some single-phase pumps
may actually run backwards.
Install an adequately sized gate valve AFTER the check
valve for pump, plumbing and check valve maintenance.
Important – Before pump installation. If pumping water,
drill a ⁄ " (3.2mm) relief hole. If pumping waste water
1
8
containing solids, drill a ⁄
3
16
discharge pipe. It should be located within the wetwell,
2" (51mm) above the pump discharge but below the check
valve. The relief hole allows any air to escape from the
casing. Allowing liquid into the casing will insure that the
pump can start when the liquid level rises. Unless a relief
hole is provided, a bottom intake pump could "air lock"
and will not pump water even though the impeller turns.
All piping must be adequately supported, so as not to
impart any piping strain or loads on the pump.
The pit access cover must be of sufficient size to allow for
inspection, maintenance and crane or hoist service.

WIRING AND GROUNDING

Important notice: Read Safety Instructions before pro-
ceeding with any wiring.
Use only stranded copper wire to pump/motor and
ground. The ground wire must be at least as large
as the power supply wires. Wires should be color
coded for ease of maintenance and troubleshooting.
Install wire and ground according to the National
Electrical Code (NEC), or the Canadian Electrical
Code, as well as all local, state and provincial codes.
Install an all leg disconnect switch where required
by code.
Disconnect and lockout electrical power before
performing any service or installation.
The electrical supply voltage and phase must match
all equipment requirements. Incorrect voltage or
phase can cause fire, motor and control damage, and
voids the warranty.
All splices must be waterproof. If using splice kits
follow manufacturer's instructions.
Select the correct type and NEMA grade
WARNING
junction box for the application and loca-
tion. The junction box must insure dry,
safe wiring connections.
Seal all controls from gases present which
WARNING
may damage electrical components.
FAILURE TO PERMANENTLY
WARNING
GROUND THE PUMP, MOTOR AND
Hazardous
CONTROLS BEFORE CONNECTING
voltage
TO POWER CAN CAUSE SHOCK,
BURNS OR DEATH.
4
" (4.8mm) relief hole in the
SELECTING AND WIRING
PUMP CONTROL PANELS AND SWITCHES
FLOAT SWITCH TYPES
There are three types of float switches typically used
on single phase pumps; single action, vertical and wide
angle.
Single action control switches can only be connected
through a control panel. Connecting them directly to a
pump will cause rapid cycling and may burn up the mo-
tor, and/or the motor start switch and/or the float switch.
If using single action switches with a control panel please
see the Float Switch and Panel Section.
Vertical mechanical float switches with piggyback plugs
are available for single phase pumps. They are an ideal
choice where there is limited space for a switch. They
require less room than a wide angle switch because they
travel in a vertical direction. Typical model numbers start
with A2H...
Wide angle float switches are the most popular type.
They can be directly connected to a pump or to a con-
trol panel. The "tether length" or the distance from the
switch body to the pivot point controls the On and Off
points and the amount pumped in one cycle. The pivot
point is where the float is attached either to the pump or
the discharge pipe. See Figures 1 - 5.
SETTING THE FLOAT SWITCHES
There are no absolute rules for where to set the float
switches, it varies from job to job.
Suggested Rules to Follow:
All floats should be set below the Inlet pipe!
Off Float: Best: set so the water level is always above the
top of the pump (motor dome). Next Best: set so the wa-
ter level is not more than 6" below the top of the pump.
On Float: set so the volume of water between the On and
Off floats allows pumps of 1½ HP and under to operate
for 1 minute minimum. Two (2) HP and larger pumps
should run a minimum of 2 minutes. Basin literature
states the gallons of storage per inch of basin height.
Lag/Alarm Float(s): should be staggered above the Off
and On floats. Try to use most of the available storage
provided by the basin, save some space for reserve stor-
age capacity. See Diagrams and Charts in Float Switch
Chart Section.
PANEL WIRING DIAGRAMS
Our control panels are shipped with instructions and wir-
ing diagrams. Use those instructions in conjunction with
this IOM. Electrical installation should be performed
only by qualified technicians. Any problem or questions
pertaining to another brand control must be referred
to that control supplier or manufacturer. Our technical
people have no technical schematics or trouble shooting
information for other companies' controls.
ALARMS
We recommend the installation of an alarm on all Waste-
water pump installations. Many standard control panels
come equipped with alarm circuits. If a control panel is
not used, a stand alone high liquid level alarm is avail-
able. The alarm alerts the owner of a high liquid level in
the system so they can contact the appropriate service
personnel to investigate the situation.