Flowserve Byron Jackson Type M - Manual (Page 48)

® Byron Jackson Double Mechanical Seal Submersible Pumping Unit • 1042.293/9 • June 04
Page 48 of 68
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Some wells will always produce a small
amount of sand at start-up. Therefore, it may
be necessary to bypass or trap out this first
flow at each start-up, particularly if a closed
piping system is used.
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When a pumping unit is known installed near
to the bottom of a well, a close check should
be kept to make sure that the well does not
sand-up (fill in) around the motor.
This is may take place without any noticeable
effect in pumping or motor operation. How-
ever, the motor is dependent on adequate
cooling from water, and any sand around it
would eventually create overheating, resulting
in at least shortened life, if not a burnout.
If this problem cannot be cured by well work,
contact Flowserve for devices that can be
added to the pumping unit to prevent its sand-
ing up.
Hydro-pneumatic pressure system
If the pumping unit is coupled into a hydro-
pneumatic pressure system, the set-up must be
designed so that the pumping unit
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does not get "water-logged" (loss of air
through water absorption without replace-
ment) and
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and does not receive too much air at each
start-up.
5.4.2 Motor operation
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Always "meg" the motor before setting a
tripped circuit breaker.
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Wait 10 minutes before restarting the motor.
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Breaking suction and/or inadequate power
supply renders warranty void.
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A time delay must be installed when any type
of automatic system is used in order to pre-
vent starting of the motor while it is spinning
backwards due to riser pipe drainback through
the pump.
A 3 minute time delay is usually adequate.
This provides a safety measure in the event a
failure in the automatic control system creates
a rapid recycle series. It also provides a time
period for the rotating element of pump and
motor to stop, after reverse rotation due to
vertical riser pipe drain- back.
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A pumping unit should not be run at closed
valve for more than 2 minutes as virtually all
the energy created is then dissipated as heat.
This condition has been known to have practi-
cally "boiled" the water in the well and created
an overheating problem for the motor.
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After the pumping unit has operated for a
longer period of time, a minimal readjustment
of the motor circuit breaker may be required
due to changed operating conditions, e. g.
sinking of the water level.
CAUTION In no case select a motor protection
adjustment setting that is greater
than the highest permissible value
given in Chapter 12.2 "Data sheet".
If the pumping unit has shut-off hand the reason
cannot be traced to a positive external source:
1. Switch off the motor.
2. Disconnect the motor from the main power
supply.
3. Disconnect the power cable leads from the
starter
4. Measure the insulation resistance of the
power cable leads to the ground (the well cas-
ing).
CAUTION Never re-set or re-fuse and start a
motor without first measuring the
insulation resistance the unit.
5.4.3 Starting frequency
The amount of regularly-distributed starts per hour
must be taken from Chapter 12.2 "Data sheet".
Higher starting frequencies are only permissible
upon written agreement by Flowserve.
Amount of maximum permissible starts in se-
quence:
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Cold motor ............................................2 starts
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Warm motor ..........................................1 starts
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Rest interval after each cycle ......... 10 minutes
It is suggested to protect the motor against non-
permitted reconnection by a time relay.