Multitec
Motor rating Y-time to be set
30 kW 3 sec. 30 %
> 30 kW 5 sec. 30 %
6.1.5 Start-up
Start-up procedure :
- The discharge-side shut-off valve must be closed.
- Start-up must proceed without abnormal vibrations or noises.
- An automatic check valve installed must open steadily when
the operating speed has been reached, without abnormal
noises, vibrations or increased power consumption of the unit.
- Open the discharge-side shut-off element.
- After the duty point has been reached, check motor input
power and bearing temperature.
After the operating temperature has been reached, switch off
the unit and re-tighten the bolts at the connecting flanges.
In the event of abnormal noises, vibrations,
temperature or leakage, switch off the unit
immediately and re-start it only after the cause for the problem
has been eliminated.
Increased temperature of the rolling element bearings after
commissioning are caused by the running-in processes. The final
bearing temperature will be established only after some operating
time (depending on the conditions up to 48 hours).
6.1.6 Shutdown
Close the shut-off element in the discharge line.
If the discharge line is equipped with a non-return or check valve,
the shut-off valve may remain open, provided there is sufficient
backpressure in the line.
- Switch off the drive, making sure that the pump set runs
smoothly down to a standstill.
- In the case of prolonged shutdown, the shut-off valve in the
inlet line has to be closed. Also close any shut-off elements in
the auxiliary feed lines.
- The shaft seal in pumps where the liquid is fed in under vacuum
must also be fed with sealing liquid during standstill.
- In the event of frost and/or prolonged shutdowns, the pump
must be drained or otherwise protected against freezing.
If the pump has to remain operational during shutdown periods,
it must be started up regularly for at least 5 minutes (see also
6.3) :
- fire-fighting pumps at least once a month
- drinking water pumps at least once in 48 hours
- standby pumps at least once a week
(it is better to operate the pumps by alternating daily)
During these periodic check runs, also check the tightness and
proper functioning of the auxiliary feed lines.
6.1.7 Final Check
After the pump has been primed, it must be easy to rotate the
coupling / shaft by hand.
There must be no impermissible leakage at the shaft seal during
pump operation.
Gland packing
The gland packing has been fitted in the factory. Its permanent
compression can only be set after several hours of pump
operation. During this running-in period, seal leakage will be
higher than during normal pump operation. Check the temperature
of the leakage.
Final adjustment of the gland packing is made gradually after
having allowed for a sufficient running-in period, so that leakage
is reduced to individual drops (approx. 20 drops per minute).
Tightening the gland cover too early or too hard without allowing
a sufficient running-in period would cause a local temperature
rise and insufficient lubrication, resulting in the destruction of the
gland packing, premature wear on the shaft protecting sleeve
and higher, uncontrollable leakage.
For speed controlled pumps or fluctuating inlet pressure, no
packing should be used, if possible. Changing pressures make
the setting of an even controlled leakage rate very difficult to
achieve.
Should these conditions occur, leakage of the gland
packing may not be stopped during any operating
condition whatsoever. With increased inlet pressure and/or
increased speed, the inevitably higher leakage of the gland
packing must not be reduced by subsequent re-tightening the
gland bolts. The setting of the minimum leakage may only be
done at lowest speed and/or lowest inlet pressure.
Mechanical seal
The mechanical seal assembly has been adjusted and installed
in the factory. It is maintenance-free. Check the seal for leakage
occasionally.
During commissioning, increased leakage may occur for a short
period of time. If leakage remains high, immediately switch off
the unit and investigate the leakage cause, e.g. contaminated
medium handled or previous dry running due to inadequate
venting of the pump.
Cooled mechanical seal (seal code 64)
If the pump is fitted with a cooled mechanical seal (seal code
64), vent the seal chamber as described in section 6.1.1.
6.2 Operating Limits
The hydraulic system is designed for pure or slightly contaminated
liquids (solid matter content max. 20 ppm). Care needs to be
taken that the operating limits indicated in the order confirmation
are complied with.
6.2.1 Temperature of the Medium Handled
Do not operate the pump at temperatures exceeding those
specified on the nameplate or the technical data sheet.
9
Time-lag relay setting for star-delta starting
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