5
Eng
lish (US
)
chapter discard.fm Page 5 Tuesday, June 7, 2011 9:29 PM
The overload should be sized and adjusted to the current
rating of the motor.
Under no circumstances should the overloads
be set to a higher value than the service factor
current shown on the motor nameplate. This
will void the warranty.
Overloads for auto transformers and resistant starters
should be sized in accordance with the recommendations
of the manufacturer.
Pump Startup
Priming the pump and venting the system
After the pump has been installed, wired and the system
filled, the following procedures should be performed.
CAUTION: Do not start the pump before priming
and venting the pump. Never operate the pump
dry.
To prime the pump in a closed system or an open system
where the water source is above the pump, close the pump
isolation valve(s) and remove the topmost drain/vent plug
from the front of the pump volute. Gradually open the
isolation valve in the suction line until a steady stream
of airless water runs out of the open plug. Replace the
plug and securely tighten. Completely open the isolation
valves.
FIGURE 4: Priming the pump and venting the system
In open systems where the water level is below the pump
inlet, the suction pipe and pump must be filled and
vented of all air before starting the pump. This is best
accomplished through the discharge port or an opening
in the discharge piping at a level above the pump volute.
Remove the topmost drain/vent plug. Pour water into the
discharge until the suction piping and pump are completely
filled. If the suction piping does not slope downward from
the pump toward the water level, the air in the line must
be purged while the system is being filled. Replace the
drain/vent plug and securely tighten. Connect and/or seal
the discharge piping.
Check motor rotation
1. Make sure power is off.
2. Check to make sure the pump has been filled and
vented.
3. Rotate the pump shaft to be certain it turns freely.
4. Verify that the electrical connections are in accordance
with the wiring diagram on the motor.
5. Briefly switch the power on and observe the direction
of rotation.
When viewed from the motor end, the
pump should rotate CLOCKWISE.
(NOTE: Direction of
rotation on HS pumps is opposite that of CR, LM/LP and
VersaFlo TP pumps).
6. To reverse the direction of rotation, first switch off the
supply power.
7. On the three-phase motors, interchange any two power
leads on the load side of the starter. On single-phase
motors, see the connection diagram on the motor and
change the wiring as required.
8. Repeat step 3 to ensure that improper rotation has not
unthreaded the impeller from the pump shaft.
9. Switch on the power and again check the motor for
proper rotation.
Starting and adjusting
Before starting the pump, be sure to check:
1. Pump is primed.
2. Direction of rotation is COUNTERCLOCKWISE when
viewed from the suction port.
3. All piping connections are tight and pipes are ade-
quately supported.
4. Suction line isolation valve is completely open (if valve
is installed).
5. For initial starting, the isolation valve in the discharge
pipe should be closed and gradually opened after the
pump is turned on. Opening this valve too fast may
cause water hammering in the discharge pipe. Unless
the discharge valve is being used as a flow throttling
device, make sure the valve is completely open.
6. Check and record the voltage and amperage of the
motor. Adjust the motor overloads if required.
7. Check and record operating pressures, if pressure
gauges have been installed.
