3 pump duty/1 standby

<P>can anybody please give me a sample ladder program/idea for 3 pump duty,1 standby operation with minimum number of timers</P>

oke what have you done so far?
with one simple line copied from the assignment is a lot to less.

Here is a version using the LogixPro simulator. I did not have time to finish it, so there are a few instructions missing on the Input (left) side of some rungs. See if you can add the missing instructions and addresses.

Arclivin,

Most of the people on this site can write a PLC program to control 4 pumps - and can do it with no timers. However, the first thing you need to do is define what you are trying to accomplish.
Are you trying to maintain a level in a tank?
Are you trying to maintain a constant flow?
Is there another parameter that you are trying to control?
Are you trying to achieve uniform wear?
Are all the pumps identical in terms of key parameters (flow rate, hp, electrical, etc.).
Are they are pumping into/out of the same destination/source?
Is there a maximum time you want to run a pump?
Are there other criteria?

Unless you can define the key parameters, there is no point in writing a program.

probably he request electrical ladder diagram.

conventional wiring.