All pumps are used to assist each other 
(run at the same time). Each pump has 
its own setpoints, (P213, 223, 233 & 
P214, 224, 234) but each time all pumps 
have stopped, then the setpoints are 
sequentially rotated between the pumps 
to ensure equal pump use. 
If a pump fails to meet the demand (due 
to malfunction, intake blockage etc.), 
then it is stopped and another pump shall 
take over. Each pump has its own 
setpoints, (P213, 223, 233 & P214, 224, 
234) but each time all pumps have 
stopped, then the setpoints are 
sequentially rotated between the pumps 
to ensure equal pump use. 
5= Duty backup and assist 
First pump comes on, if it cannot cope, 
it goes off and next pump comes on 
(duty backup). This continues until the 
last pump comes on and if it cannot cope 
the first pump comes back on to assist 
the last pump  (duty assist) if the level 
continues to rise all other pumps will 
come on (assist) in turn until the level 
decreases to the pump off points. Each 
pump has its own setpoints, (P213, 223, 
233 & P214, 224, 234). 
6= Service ratio duty assist 
All pumps are used to assist each other 
(run at the same time) and each pump 
has its own setpoints (P213, 223, 233 & 
P214, 224, 234). And a service ratio 
setting. The third setpoint (P215, 225, 
235) is used to set the service ratio. Each 
time a pump is required to start then the 
pump with the least running hours (with 
respect to the service ratio) is started 
(i.e. the setpoints are re-assigned 
accordingly).  For example, if two 
pumps A and B have the service ratio set 
to 2 and 1 respectively, then pump A 
will operate for twice as many hours as 
pump B.