FP USER INSTRUCTIONS ENGLISH 71576286 - 07/06
It is strictly forbidden to open switch cupboards, switch boxes, or all other live electric equipment. If it is necessary to open them in order to take readings, to carry out tests or adjustments for example, only a skilled technician may do them with adapted tools. Make sure that physical protections against electrical risks are used.
5.5.4 Bearings
If the pumps are working in a potentially explosive atmosphere, temperature or vibration monitoring at the bearings is recommended.
If bearing temperatures are to be monitored it is essential that a benchmark temperature is recorded at the commissioning stage and after the bearing temperature has stabilized.
Record the bearing temperature (t) and the ambient temperature (ta)
Estimate the likely maximum ambient temperature (tb)
Set the alarm at
and 105 C (220 F) for grease lubrication
It is important, particularly with grease lubrication, to keep a check on bearing temperatures. After start up the temperature rise should be gradual, reaching a maximum after approximately 1.5 to 2 hours. This temperature rise should then remain constant or marginally reduce with time.
5.5.5Normal vibration levels, alarm and trip For guidance, pumps generally fall under a classification for rigid support machines within the International rotating machinery standards and the recommended maximum levels below are based on those standards.
Alarm and trip values for installed pumps should be based on the actual measurements (N) taken on site on the bearing housings of the pump in the fully commissioned as new condition.
The example (N) value is given for the preferred operating flow region (typically this may extend to 70 to 120 % of the pump best efficiency point); outside the preferred flow region the actual vibration experienced may be multiplied by up to 2.
These standard values can vary with the rotational speed and the power absorbed by the pump. For any special case, do not hesitate to consult us. Measuring vibration at regular intervals will then show any deterioration in pump or system operating conditions.
Vibration Velocity - unfiltered | Horizontal Configuration | ||
mm/s (in./s) r.m.s. | |||
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Normal | N | 5.6 (0.22) | |
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Alarm | N x 1.25 | 7.1 (0.28) | |
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Shutdown Trip | N x 2.0 | 11.2 (0.44) | |
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5.5.6 Stop/start frequency
Pump sets are normally suitable for the number of equally spaced stop/starts per hour shown in the table below. Check actual capability of the driver and control/starting system before commissioning.
Motor rating kW (hp) | Maximum stop/starts | |
per hour | ||
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Up to 15 (20) | 15 | |
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Between 15 (20) and 90 (120) | 10 | |
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90 (120) to 150 (200) | 6 | |
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Above 150 (200) | Refer | |
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Where duty and standby pumps are installed it is recommended that they are run alternately every week.
5.6 Stopping and shutdown
5.6.1Stopping and restarting in continuous running
According to hydraulic conditions of the installation and its automation degree, stop and restart procedures can have different forms. Nevertheless all of them must respect imperatively the following rules:
Stopping:
a)Avoid that the unit turns in the opposite direction to the normal running.
b)Make sure that the discharge line pressure does not reach the foot valve.
c)Avoid a continuous running below the authorized flow rate (see § 5.4.2).
Restart:
a)Ensure that the pump is completely full of liquid.
b)Ensure a continuous supply with a sufficient available NPSH.
c)Ensure a backpressure so that the motor power is not in excess.
d)
Respect the starting frequency imposed by the motor manufacturer.
e)
Protect the pump against water hammer when stopping or starting.
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