Volume 8 – Mechanical and Electrical Services - Malaysia Geoportal
Volume 8 – Mechanical and Electrical Services - Malaysia Geoportal
Volume 8 – Mechanical and Electrical Services - Malaysia Geoportal
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Chapter 1 PUMPING INSTALLATION<br />
Monitoring system is to be built-in to ensure reliable, safe <strong>and</strong> efficient pump operation. Monitoring<br />
features shall include (i) status indication of plant operating conditions (ii) alarm monitoring of plant<br />
parameters for malfunctioning <strong>and</strong> out-of-limit conditions <strong>and</strong> (iii) automatic protective shutdown<br />
devices for faulty operating conditions <strong>and</strong> set-limit conditions. Typical pump/motor monitoring unit<br />
is as shown in Fig. 1.6.<br />
Fig. 1.6 Pump / Motor Monitoring Unit<br />
In multiplex pump stations, features such as pump cycling <strong>and</strong> sequencing timing are incorporated.<br />
Pumps are operated to meet the varying inflow / outflow dem<strong>and</strong>s of the system. Alternating pump<br />
starting will help in equalizing pump wear <strong>and</strong> minimizing the starting frequency of each particular<br />
pump.<br />
1.6 PUMP NUMBERS DETERMINATION<br />
In determining the number of pumps to be used, it is necessary to consider the following factors: -<br />
a) Pumping capacity required for the proposed scheme;<br />
b) Equipment cost <strong>and</strong> operating cost;<br />
c) Operational control system;<br />
d) Reliability <strong>and</strong> critical situation, <strong>and</strong><br />
e) Civil construction cost.<br />
To maintain the flexibility in operation <strong>and</strong> to adopt the dem<strong>and</strong> variation, preferably sufficient<br />
number of same capacity pumping unit should be provided. Considering reserve capacity of the<br />
pumping installation, sometimes an additional same capacity unit may be installed as st<strong>and</strong>by to<br />
cater for emergency use particularly for storm water pumping installations. Generally 3 to 4 duty<br />
pumpsets are preferred. If two (2) pumpsets are installed, each pump should be sized to pump not<br />
less than 2/3 of the total capacity required.<br />
In flood control application, one (1) smaller capacity pumping unit is normally provided to cater for<br />
low flow condition while the larger duty pumps dealing with all flood/storm water. However, in<br />
automatic control stations the number of pumps may be governed by the available depth between<br />
the highest cut-in <strong>and</strong> lowest cut-out levels.<br />
March 2009 1-9
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