Manual

Analog Panel Meter Instruction Manual

Pump Alternation Control Applications (Altern)

For pump control applications where two or more similar pumps are used

to control the level of a tank or a well, it is desirable to have all the

pumps operate alternately. This prevents excessive wear and

overheating of one pump over the lack of use of the other pumps.

Up to 8 relays can be set up to alternate every time an on/off pump cycle

is completed. The set points and reset points can be programmed, so

that the first pump on is the first pump off.

Application #1: Pump Alternation Using Relays 1 & 2

1. Relays 1 and 2 are set up for pump alternation.

2. Relays 3 and 4 are set up for low and high alarm indication.

Set and Reset Point Programming

Relay Set Point Reset Point Function

1 30.000 10.000 Controls pump #1

2 35.000 5.000 Controls pump #2

3 4.000 9.000 Controls low alarm

4 40.000 29.000 Controls high alarm

Pump Alternation Operation

1. Pump #1 turns on when level reaches 30.000, when level drops

below 10.000 pump #1 turns off.

2. The next time level reaches 30.000, pump #2 turns on, when level

drops below 10.000, pump #2 turns off.

3. If the level doesn’t reach 35.000, pump #1 and pump #2 will be

operating alternately.

4. If pump #1 cannot keep the level below 35.000, pump #2 will turn on

at 35.000, then as the level drops to 10.000, pump #1 turns off,

pump #2 is still running and shuts off below 5.000.

5. Notice that with the set and reset points of pump #2 outside the

range of pump #1, the first pump on is the first pump to go off. This

is true for up to 8 alternating pumps, if setup accordingly.

6. Relay #3 will go into alarm if the level drops below 4.000 and relay

#4 will go into alarm if the level exceeds 40.000.

7. Adding the 4 external relays expansion module allows using the 4

SPDT internal relays for pump alternation and the 4 SPST external

relays for high, high-high, low, and low-low alarm indication.