Question
QUESTION: Last season we replaced the pump which feeds our sprinkler system. The former pump ran constantly during sprinkler cycles, this one turns on and off about every 10 seconds or so; seems like that could be hard on the pump.  What do you recommend?
Scott

ANSWER: Thanks for the question.
It sound to me as if your new pump has a pressure switch. It either needs to be adjusted or eliminated depending on the type of system you have. Do you have a pressure tank? If so, you need to adjust the switch to a higher setting. Those instructions are usually inside the cover. If you have no tank the I suggest eliminating or bypassing the switch.
Where the wire goes into the pump is there a small box about 3" square? That's a pressure switch. To bypass you need to hook the power supply wires direct to the motor wires. If your not familiar with electricity have an electrician do this.
If you can tell me whether you have a pressure tank or not, I'll be able to give you better instructions as to how to resolve the problem.

Matt


---------- FOLLOW-UP ----------

QUESTION: Thanks for the quick response. It has a pressure tank.

Answer
Thanks for the updated info.
The pressure switch is a approximately 3" square box. Before you start adjustment, I must warn you. Inside the pressure switch is high voltage. Be very careful!!!!!! You'll need to remove the top to access the adjustment screw or nut. On most switches there are 2 screws one being taller. Start by turning the taller screw in (clockwise) about 1 turn. Turn on the irrigation. I use the smallest zone, it will be the one most prone to cycling. If the zone still cycles, turn the screw another turn. Continue doing this till the pump stays on or at least runs for a few minutes. Now, shut off the irrigation and make sure the pump shuts off. This may take a minute or two. If it doesn't, turn the screw counterclockwise 1/2 turn. It's a process of going back and forth till you get it right.
it is possible  the bladder in the pressure tank is bad. This will cause the quick cycling you have. The pressure switch adjustment will help the tank but not cure it. To check the tank. Find the air valve, it looks like a tire valve. Stick a screw driver in the end for a second or two. If you get water, the tank is bad.
Good luck, if you have further question, feel free to ask.

Matt