Thursday, July 29, 2010

Using Your Mechanical Irrigation Timer

Of the homes the UCU has visited in Miami, 70% have mechanical irrigation timers. With any irrigation timer it is important to understand how to program it and use it correctly.

The yellow arrow in this picture is pointing towards the on/off switch. If the switch is all the way up then the system is set to run automatically based on the days and times programmed into the timer. If the switch is in the middle (as shown) then the system is off and will not run as programmed. Dropping the switch down causes the irrigation to turn on and it will not turn off until the switch is flicked back up to either the off or auto position.

Have you ever wondered if you were irrigating on the right day? The yellow arrow in this picture is pointing at the spring attached to the "Day of the Week" dial. A simple rule for telling what day of the week it is according to your timer: the spring touches the current day. In this picture the spring is touching Saturday, and so according to the timer it is 10 am (silver dial in middle of big yellow dial) on Saturday.

Each little silver pin on the day of the week dial sets whether that day is an irrigation day or not. If the silver pin is pulled partially out (but still attached to the dial), then that day is set to irrigate. If the pin is pushed all the way in, then irrigation will not happen on that day.

This yellow arrow is pointing at the large silver pin on the "Time of Day" dial. This pin will cause the "Day of the Week" dial to turn. Ideally, you would place this pin at midnight so that at midnight the "Day of the Week" dial will turn and the timer will have a correct setting for the day of the week.

This yellow arrow is pointing at the copper irrigation pins. The number of copper pins determines the length of time irrigation will run in a zone. Each pin is equal to 12 minutes of irrigation, most irrigation zones will need 1 to 2 pins (24 mins). If you have an area with all grass that is irrigated with rotors (see Operation of Residential Controllers) then you may need 3 (36 min) to 4 pins (48 mins). To cause irrigation to switch between the zones, breaks need to be placed between the copper pins.

Example: you have 2 irrigation zones (areas) that you want watered 24 minutes starting at 4 am.

1. Place 2 copper pins with the first at 4 am.

2. Leave one slot empty (12 minute break)

3. Add 2 more copper pins after the empty slot.

Reminder: it is best to irrigate in the early morning rather than the evening to prevent plant fungus and disease.


One problem with these mechanical timers is that when the power goes out the timer will stop keeping time. Make sure to check your timer regularly to verify that the day of the week and the time of day are set correctly.

No comments:

Post a Comment