lawn sprinkler troubleshooting

[Burt]

I have 6 zones on my lawn sprinkler system. The three solenoids clustered along the side of the house actuate and work fine. The three in the front do not. I put a volt meter on the three in the front and at first got no voltage at the solenoid when there was voltage at the box. So then I ran an above-ground wire from the ground in the back solenoids to the front and got a strong 29 volts across the front solenoid. Then I disconnected the three below- ground connections out front and recorded 8 volts across a front solenoid from the incoming below ground leads! Not enough to actuate it, but I am befuddled by the low, partial voltage reading. Does the 8 volts indicate a faulty wiring scheme or that there is a weakness in the insulation somewhere between the two clusters?

I hate to dig a trench between the two clusters to install new wire if it's not necessary. If I must do so, should I buy new 7 conductor wire rather than try to run a single new ground lead?

 

[Bill_W]

Polarity conscious? Black and white wire? All black (or white) tied together with one common is 4 wires for 3 solenoid. If I was still working I would break out my Megger to check insulation to ground. Usually just one wire is bad. You can run a extension cord ( not plugged in) and use one conductor from one end each individual wire and use a ohm meter to check continuity.

 

[Burt]

Originally Posted by Bill_W
Polarity conscious? Black and white wire? All black (or white) tied together with one common is 4 wires for 3 solenoid.


Are you saying I need to have a three-fingered "Y" off the incoming ground as opposed to take-offs along a single, commo ground wire? Please be real basic with me.

 

[Oildudeny]

All commons wires do get bundled together. You can use a 9v battery to test solenoid or just move the wires over to the zones that function in the control box

 

[Bill_W]

You can tie three solenoid wires together for a common wire and have 3 hot wires, the hot wires will be connected to the station number terminal. If you have 7 conductors now it will work with 4 (3 hot, 1 common)

 

[Donald]

I would look for connectors to be faulty before a wire. Keep in mind if a connection or wire is not doing its job you can get the proper voltage if measuring without being connected to a solenoid, but once there is any load then the voltage drops.

 

[thastinger]

Originally Posted by Burt
I have 6 zones on my lawn sprinkler system. The three solenoids clustered along the side of the house actuate and work fine. The three in the front do not. I put a volt meter on the three in the front and at first got no voltage at the solenoid when there was voltage at the box. So then I ran an above-ground wire from the ground in the back solenoids to the front and got a strong 29 volts across the front solenoid. Then I disconnected the three below- ground connections out front and recorded 8 volts across a front solenoid from the incoming below ground leads! Not enough to actuate it, but I am befuddled by the low, partial voltage reading. Does the 8 volts indicate a faulty wiring scheme or that there is a weakness in the insulation somewhere between the two clusters?

I hate to dig a trench between the two clusters to install new wire if it's not necessary. If I must do so, should I buy new 7 conductor wire rather than try to run a single new ground lead?


Sounds like your cable to the inop box is damaged somewhere. Do you have the full 7 wire cable going into the box where none of the valves are getting voltage? If so, move some of the wires onto the other zone screws in your controller and see if you have the 24V on any of those wires, if so, you could just use those wires.

 

[Bill_W]

A voltage drop with wires connected kinda points to two wires shorted in your 7 conductor. Disconnected at both ends and using a ohm meter you can do a complete rotation test of each conductor combination. Like said you only need 4 of the 7 conductors to make it work.

 

[Burt]

Originally Posted by Donald
I would look for connectors to be faulty before a wire. Keep in mind if a connection or wire is not doing its job you can get the proper voltage if measuring without being connected to a solenoid, but once there is any load then the voltage drops.


Per your recommendation, I redid the connections and sanded the copper wires. It was weird in that it started giving signs of adequate voltage and not working and then one by one they started working.

I soldered the good connections and put the water resistant caps on them.