Starting And Adjusting; Operation And Maintenance; Operation; Maintenance - Grundfos SR Installation And Operating Instructions Manual

7.6.1 Starting and adjusting

Before starting the pump, check the following:
1. The pump is primed.
2. The direction of rotation is clockwise when viewed from the
motor end.
3. All piping connections are tight and pipes are adequately sup-
ported.
4. The suction line isolation valve is completely open (if valve is
installed.
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 ham-
mering in the discharge pipe. Unless the discharge valve is
being used as a flow throttling device, make sure the valve is
completely open.
In addition:
5. Check and record the voltage and amperage of the motor.
adjust the motor overloads, if required.
6. Check and record operating pressures, if pressure gauges
have been installed.
7. Check all controls for proper operation. If the pump is con-
trolled by a pressure switch, check and adjust the cut-in and
cut-out pressures. If low-water-level controls are used, be sure
the low-water-level switch is properly adjusted so the pump
cannot run if the pump should break suction.

8. Operation and maintenance

8.1 Operation

Pump
The pumps are water-lubricated and do not require any external
lubrication or inspection.
Under no circumstances should the pump be operated for any
prolonged periods of time without flow through the pump.
This can result in motor and pump damage due to overheating. A
properly sized relief valve or bypass line should be installed to
allow sufficient water to circulate through the pump to provide
adequate cooling and lubrication of the pump bearings and seals.
Motor
Pump cycling should be checked:
• 1 hp to 5 hp: Max. 20 starts per hour
• 7.5 hp to 15 hp: Max. 15 starts per hour
• 20 hp to 40 hp: Max. 10 starts per hour.
Rapid cycling is a major cause of premature motor failure due to
increased heat build-up in the motor. If necessary, adjust controls
to reduce the frequency of starts and stops.

8.2 Maintenance

Pump
The pump is maintenance-free.
If the pump is to be drained for a long period of inactivity, inject a
few drops of silicone oil on the shaft between the motor stool and
the coupling. This will prevent the shaft seal faces from sticking.
Motor
The motor should be checked at regular intervals. It is important
to keep the motor clean in order to ensure adequate ventilation. If
the pump is installed in a dusty environment, the pump must be
cleaned and checked regularly.
Lubrication
The bearings of motors up to 15 hp are greased for life and
require no lubrication.
The bearings of motors of 15 hp and up must be greased in
accordance with the indications on the motor nameplate.
The motor should be lubricated with a polyurea-based grease
meeting the following specifications:
• NLGI grade 2
• Viscosity of basic oil: 115 cSt at 104°F (~ 40°C).
Temperature range: –22°F (~ –30°C) to 284°F (~ 140°C) during
continuous operation.
Do not over-grease the bearings. Over-greasing causes
increased bearing heat and can result in bearing/motor failure.
Preventative maintenance
At regular intervals, depending on the conditions and time of
operation,
• check that the pump meets required performance and is oper-
ating smoothly and quietly.
• check that there are no leaks, particularly at the shaft seal.
• check that the motor is not overheating.
• remove and clean all strainers or filters in the system.
• verify the tripping of the motor overload protection.
• check the operation of all controls; check control cycling twice
and adjust if necessary.
If the pump is not operated for unusually long periods, the unit
should be maintained in accordance with these instructions. In
addition, if the pump is not drained, the pump shaft should be
manually rotated or run for short periods of time at monthly inter-
vals.
If the pump fails to operate or there is a loss of performance, see
section 10.2.

8.3 Taking pump out of operation

Freeze-protection
Pumps which are not being used during periods of freezing
should be drained to avoid damage.
To drain the pump,
1. close the isolation valves
2. remove the drain/vent plugs at both the top and bottom of the
pump volute.
Ensure that the escaping water does not cause injury
to persons or damage to the motor or other compo-
nents.
In hot-water installations, pay special attention to the
risk of injury caused by scalding hot water.
Do not replace the plugs until the pump is to be used again.

9. Service

If a pump has been used for a liquid which is injuri-
ous to health or toxic, the pump will be classified as
contaminated.
If Grundfos is requested to service the pump, Grundfos must be
contacted with details about the pumped liquid, etc. before the
pump is returned for service. Otherwise Grundfos can refuse to
accept the pump for service.
Possible costs of returning the pump are paid by the customer.
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