Davey VM Series Stainless Steel Vertical Multistage Pumps - Manual (Page 4)

4
Refer to the motor data plate for its electrical characteristics
(frequency, voltage, nominal current).
The three-phase and single phase dual voltage motors must
be protected by a circuit-breaker or magnetic contactor with
overload set to the current marked on the motor data plate.
Provide a fused disconnecting or isolating switch, in
compliance with local standards.
The electric connections should be made as shown in the
diagrams inside the cover of the motor terminal box.
DO NOT FORGET TO CONNECT THE EARTH.
The orientation of the motor can be changed a quarter turn by
removing the motor attachment screws (if necessary, remove
the coupling guards) and turning the motor to the desired
position.
Refit the screws and the coupling guards.
The standard three phase electric motors used with pumps can
be connected to a frequency converter.
Strictly follow the directions given by the manufacturer’s
data sheet.
The converter must not generate a peak change of voltage dV/
dt in excess of 500 V/ms, since this would cause noise and
damage the motor winding.
If it does, place an LC (inductance-capacitance) filter between
the converter and the motor.
Starting Up
Filling or Priming
Pump in flooded suction installation
• Close the discharge valve.
• Unscrew the bleed plug fitted to pump head.
• Open the suction valve progressively and completely fill the
pump.
• Screw the bleed plug back in only after water flows out and
all air has been eliminated.
In a hot-water application, a stream
of water may escape from the bleed
port. Do what is necessary to
protect persons and the motor.
Pump with suction lift
• Close the discharge valve.
• Open the suction valve if fitted.
• Remove the bleed plug on the main body of the pump.
• Unscrew the bottom drain and priming plug on the pump
casing four or five turns.
• Put a funnel into the bleed plug and slowly and completely
fill the pump and the suction pipe.
• When water flows out and all air has been eliminated, filling
is complete.
• Screw the bleed plug and the bottom drain and priming plug
back in.
The following must be done in addition after the filling plug has
been screwed back in:
• Start the motor briefly.
• Unscrew the prime plug again and top up the water in the
pump.
• If necessary, repeat this operation until all air is expelled
from pump.
Dry-running protection
To avoid accidental loss of prime of the pump, we recommend
protecting it with a suitable device.
Check direction of rotation
Turn the coupling by hand to make sure that it turns freely,
without sticking.
Power up the motor by briefly pressing the circuit-breaker and
check that it turns in the direction indicated by the arrow on the
pump head.
If not, for three phase, interchange two of the three active wires
on the motor terminal block or circuit-breaker. Note that this
work must be carried out by a suitably qualified person.
For single phase check wiring diagram in terminal box lid.
NOTE: Direction of rotation of the motor diagram is when
viewed from the motor shaft end.
Starting up
The pump must not be operated in a no-
flow condition (discharge valve closed) for
more than 5 minutes with cold water
(< 40 o C) or more than 2 minutes for hot
water.
We recommend establishing a minimum flow of about 10% of
the rated capacity of the pump, to avoid the formation of a gas
pocket at the top of the pump. Open the discharge valve to
start the pump. Use a pressure gauge to check the stability of
the discharge pressure; if it is unstable, bleed the pump again
or repeat the priming operation.
Check that the current draw does not exceed the value marked
on the motor data plate.
Servicing
No special servicing is required in normal operation. Always
keep the pump perfectly clean, particularly the motor and motor
fan cover.
For a prolonged shutdown, if there is no risk of frost, it is best
not to drain the pump.
To avoid blocking of the shaft and the hydraulic system, in
frosty periods, empty the pump by removing the drain plug and
the air bleed plug.
• Screw the 2 plugs back in loosely, without tightening them.
Motors without grease fittings
The bearings are greased for life and so need no lubrication.
Mechanical seal
The mechanical seal needs no servicing in operation.
It must never be allowed to operate dry.
Never operate the pump dry, even briefly.
A connection error will damage the motor.
The power cable must never touch the pipe
or the pump; make sure that it is protected
from any moisture.