Xylem MPAI - Manual (Page 87)

Installation, Operating and Maintenance Instruction
Model MP, MPA, MPAI
MP 100-english page 83 Revision 04
Article No 771074011 Issue 11/2011
6.2 Switch on drive
Immediately (max. 10 seconds on 50 Hz resp.
max. 7 seconds on 60 Hz currency feed) after
reaching normal operating speed open discharge
valve adjust the required operating point. The
pumping data shown at the type plate resp. in the
data sheet and / or the order confirmation must be
met. Every change is only permitted after talking
with the manufacturer!
Operation with closed valve in the suction and /
or discharge piping is not permitted.
On starting-up without back-pressure, the back-
pressure must be produced through throttling at
the discharge side. After reaching full back-
pressure open valve
In order that the shaft sealing can be monitored
and maintained unhindered, no protection cover
is provided in this area. Therefore special
attention is required when pump is working (no
long hair, loose clothes, a.s.o.).
Packing: Packing need leakage for trouble free
function (drop wise outlet of pumped medium).
Adjust ample leakage in the beginning. Reduce
that slowly during the first operating hours by
continuously fastening of gland (see position "69"
and "M3" in sectional drawing) when pump is
running. Assume 60-100 drops / minute as
approx. value.
The leakage must flow out liquid in any case (not
vaporous).
Packing that run dry will harden and then
destroy the shaft sleeve and/or the shaft.
Mechanical seals: Mech. seals don't need to be
maintained and are almost free of leakage.
If pump does not reach attended head or if
atypical sounds or vibrations do occur:
Switch off pump (see chapter 6.7) and seek for
causes (see chapter 10).
6.3 Restarting
Basically, the same procedure should be followed as
for starting up for the first time. However, there is no
need to check the direction of rotation and the
accessibility of the pump unit.
The pump should only be automatically restarted if it
has been made sure that the pump has remained
filled whilst stand by.
Be particularly careful not to touch hot machine
parts and when working in the unprotected shaft
seal area. Remember that automatically
controlled systems may switch themselves on
suddenly at any time. Suitable warning signs
should be affixed.
6.4 Limits of Operation
The operating limits of the pump / unit regarding
pressure, temperature, performance and speed
are shown in the data sheet and / or order
confirmation and must be observed under any
circumstances!
Do not exceed the output given on the motor
name plate.
Avoid sudden changes in temperature
(temperature shocks).
The pump and motor should run evenly and
without vibrations; check at least once a week.
6.4.1 Flow min. / max.
If no other data are given in the curves or data sheets,
the following is valid:
Q
min
= 0,1 x Q
BEP
for for short time operation
Q
min
= 0,3 x Q
BEP
for continuous operation
Q
max
= 1,2 x Q
BEP
for continuous operation *)
Q
BEP
= Flow in efficiency optimum
*) on condition that NPSH
facility
> (NPSH
pump
+ 0,5 m)
6.4.2 Abrasive Media
On pumping liquids with abrasive components
an increased wear at hydraulic and shaft sealing
must be expected. The intervals of inspection
should be reduced compared to the usual
times.
6.4.3 Permitted number of starts
With electric motors, the permitted number of starts is
given in the attached motor operating instructions.
If no values for the switching frequency are given in
the motor operating manual, the values according to
Diagram 7 apply.
1,0
10,0
100,0
1 10 100 1000
Motor power [kW]
m
ax
. p
er
m
. s
ta
rt
s/
h
Diagram 7
If two different figures are given, the lower figure is
valid.