Intermatic Timer

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batch

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I changed a friends timer guts out because it was not keeping the correct time.

The timer is for his sprinklers at his house. The voltage to the motor is 114.3 volts. The service is only 114.3 on one leg and 114.9 on the second. If I remember correctly the code used to limit the combined voltage drop to a total of 5% between the POCO and the electrician to his furthest run. I thought is was 3% for one and 2% for the other. So at the lowest shouldn't I get 116.4 at the panel?

Also, I checked the original timer and it had the hot conductor connected to the "Common" terminal. The grounded conductor to "Clock" and the load was connected to a terminal marked No. (IFIRC)

I thought that this was wrong. The motor turned in either configuration. But the switch for off/on/auto was going to "common" and the "load" (No.).

Any way the two questions are could the lower voltage be affecting the clock motor? If so could the voltage have dropped on the POCO's side recently. They have lived in this same house for about 15 years and the timer worked fine.

I have always refered to the wire from the power source as "line". The wire from the equipment being powered as "Load". The white grounded conductor as the Neutral or Common. Is that wrong.

BTW, the scematic for the clock seemed to show the load as "Line".

Here is a link to the for the clock with a link to the instructions included on that page.

http://www.intermatic.com/Default.asp?action=prod&pid=9120&sid=233&cid=51&did=5

I install Intermatic clocks all the time and they are usually marked for line, load and neutral. So this threw me for a loop...
 
A lower voltage should have little/no effect on timekeeping. The motors are synchronized to the ac cycles of the line. I have a similar timer and the motor is listed as good for 100v-250v AC.

I suspect that this timer is an old one, and the terminal marked NO stands for Normally Open, in other words that what ever you have on that terminal will be off until the timer acts on the switch to energizes the terminal.


just my 2 cents, hope it helps
 
I got a bad batch of timers once that had messed up trippers. The trippers would actually jam the dial and burn out the motor.
 
I agree that the voltage should not mess with the timer. Also, around here the POCO's fluff factor is +/- 10%. 114V doesn't sound unreasonable to me, but you may want to check with the POCO and see what their policy is.
 
paul said:
I agree that the voltage should not mess with the timer. Also, around here the POCO's fluff factor is +/- 10%. 114V doesn't sound unreasonable to me, but you may want to check with the POCO and see what their policy is.
Click to expand...


I agree and there is no voltage drop requirement in the NEC. Just an FPN which is a suggestion.
 
batch said:
If I remember correctly the code used to limit the combined voltage drop to a total of 5% between the POCO and the electrician to his furthest run. I thought is was 3% for one and 2% for the other. So at the lowest shouldn't I get 116.4 at the panel?
Click to expand...

Depends. Do you know what the voltage is at the transformer terminals?
 
Pierre C Belarge said:
There are voltage requirements in the NEC, just not for general wiring, the requirements are specific, such as Fire Pumps, sensitive electronic equipment.
Click to expand...


True, I referring directly to the installation outlined in the OP. But you are correct that there are VD requirements for a few specific installations.
 
Thanks for the replies.

What about the TC only operating correctly when the line was connected to the terminal marked common? Any ideas why that would be.
 
I have Intermatic "calendar face" 7 day clocks on my project. These clocks have a 3 terminal relay. This relay is just a 2 position switch. Feed the common and either 1 or 2 is energized depending on the position of the tripper. The clock motor is fed off the common with a separate neutral terminal. I suspect you may have this same type setup.
 
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