I have an older hot tub with a Brett Aqualine EM-104 control box, wired 220V. Recently I had to change the Diehl 24hr timer switch. It worked fine for about 3 weeks, and now GFCI breaker is tripping. I am able to reset and check in a few hours and it would be tripped again.

Not thinking it could be the Diehl timer, I started checking everything from relays to the contactors (the contactors look burned). When the tub was on, I could not make it trip with any combination of actions (turning jets on, calling for heat and light etc…).

So I disconnected the feed lines to the timer, so the tub runs when it needs heat, and it has not tripped since. The timer is set to circulate only for a few selected hours a day.

After my rather long explanation, my question: in your experience, have you seen a simple timer be the cause of such a problem? Or is this possibly masking another problem? I still have a hard time believing it is the timer.

Thanks

There could be, or maybe not be something with this.

I take the conventional approach anyway and start considering the frequency of operation (more often?) and circuit loading with the timer hooked up.

Has the breaker ever been very warm or hot when it trips?

Thanks for the reply --

I did check the breaker, as I read in a previous post of yours, for wire connections and burning on contacts. All wire are tight and I removed and checked and reseted breaker. All appears good.

I cannot pinpoint the frequency of the tripping of the breaker, all I know is I was able to reset and let it run, and I would walk away for a while (1 or 2 hours) and it would be tripped again. My wife checked it at one time 15min after reset and it was tripped.

I don't know what added load the timer would add to the circuit, it basically runs just the low circulation jets (same as when the heater is on).

Is there another type of timer compatible with the Diehl (same demisions for mounting) that you could recommend trying?

Thanks again

I had a feeling it might come across like that but what I meant was the frequency of running the system being increased by the timer... (lol not the timer motor itself!).

This will replace the Diehl timer.
http://spapartsnet.com/products/ELTMG101.html

hmmm, unless your timer motor has moisture in the windings, this one is strange.

If you mean the setting of the timer, I've tried 1hr setting on/off in 24hr period, and up to 6 on/off cycles in 24hr period and they all tripped.




I don't think there would be moisture in the winding of the pump, I would think it would trip breaker anytime using the pump.

I did notice on the back of the timer it has a rating listed 1.5hp 240V and 1.0hp 120V, and it is listed at 120V 60HZ. Why is does it reference hp of the motor?




I took a look at the replacement you suggested, I think I am going to give it a try. (It is worth $50 compared to a weeks worth of aggravation!)

Thanks again