Davey 6 Submersible Borehole Pumps - Manual (Page 6)

6
8. Water Temperature
Reduced motor loading in water over 30oC (86oF)
Approximate Allowable % of Maximum Nameplate Amps
Water
Temperature
Through 3 hp
(2.2 kW)
5-15 hp
(3.7-11 kW)
Over 15 hp
(11 kW)
35ºC 100% 100% 90%
40ºC 100% 90% 80%
45ºC 90% 80% 70%
50ºC 80% 70% 60%
55ºC 70% 60% 45%
Do not use submersible motors in water over 55oC
(130oF).
With proper water flow past the motor, submersible
motors are designed to operate up to nameplate
amperage rating in water as hot as 30oC. If the
water temperature exceeds 30oC, reduce the load by
changing pumps or throttling the pump discharge.
9. Maximum Start & Pressure
System Installation
Davey submersible borehole pumps may be used as
a pressure system in conjunction with pressure tanks
providing a suitable draw off capacity.
Caution: The operation of large Submersible units as
automatic pressure systems must be done with great
care.
When selecting a pressure tank, make sure that the
rated tank pressure is at least 10% greater than the
maximum pump pressure at the bore head. Ensure
tank draw off accommodates the least amount of
starts as possible, and does not exceed the number of
starts listed in the following table.
Frequency of Starts
Motor Rating
Average Starts per day
per 24 hour day
kW hp Single Phase Three Phase
.75 to 4.0 1 to 5.5 100 300
5.5 to 22 7.5 to 30 100
Over 22 Over 30 100
While small capacity tanks may be used, extreme
care must be taken to ensure the pump unit does
not ‘cycle’. It may be necessary to fit more than one
pressure tank to provide the required draw off or to
help prevent pump cycling.
For further information on these contact your Davey
Dealer.
NOTE: Any automatic switching of the pump giving
excessive starts per hour will shorten the life of the
unit and damage caused may affect guarantee.
WARNING: Failure to use correct starting
equipment and overloads may damage your
Submersible Motor. This damage may not be
covered by guarantee.
Davey supply a range of control boxes incorporating
various switching devices and the use of these
products is recommended.
10. Maintenance and Service
If the pump has been used for a liquid which is
hazardous to health or toxic, the pump will be
classified as contaminated.
10.1 Operation & Maintenance
The pump must not be operated with the delivery
valve shut off (closed head) for more than a few
seconds, otherwise the motor will overheat,
possibly causing permanent damage.
While Davey submersible pumps do not require
regular maintenance, it is a good practice to monitor
the conditions and performance of the pump and
motor. this diagnosis may be carried out by checking
the maximum pressure (shut valve for a very short
period) generated by the pump, and by checking the
amperage draw of the motor at standard duty flow
rate.
Both these figures should be compared to pressures
and current draws recorded when the unit was initially
installed. Any reduction in pressure may indicate
wear in the pump, while any increase in motor current
indicates a possible overload condition. Consult the
pump service chart for further diagnosis of possible
causes.
All pumps are easy to service.
Use only Service kits and tools suitable for
maintenance.
The Service Manual is available on request.