View Full Version : Astro timer for FX transformer?

08-21-2010, 10:05 AM
I've got a client with existing FX and Unique transformers. The original contractor installed mechanical timers and they're not happy with them so I'm replacing them with astro timers. I'm able to get the Intermatic astro timer to work fine in the Unique transformers but if I try to install it in the FX transformers, it will trip the breaker. Anybody know what timer will work in the FX transformers?

Thanks in advance.

08-22-2010, 01:17 PM

The only reason why a breaker would be tripping is that you have a dead short or an overload situation. Ensure that the wiring has been done correctly (120v by an electrician). That is if you are referring to the primary feed breaker.
A little more detailed information would be helpful and I would be glad to offer some help.


08-22-2010, 01:47 PM
My electrician was actually there when I was doing this and did check all the wiring.

The only thing I was doing "odd" is that I was pluggin the timers in upside down because the plug is on the bottom of them and the transformer plug has very little clearance above it. I tried 2 different timers on 2 different transformers and they both do the same thing, the spark out like there is a short and then the service breaker trips. It's really bizarre.

If I can find a digital astro timer with the plug at the top of the timer I hope it will work better. If not, I'm going to replace the transformers and write it off to some FX oddity. FX wouldn't have been my choice for a transformer anyway.

08-22-2010, 06:01 PM

You say you are turning the timer upside down? When you do this the polarity will be reversed hence a dead short and damage could be done to the timer and/or the transformer.
You are reversing the hot and neautral when doing what your doing. Most timers that I use have the female end at the side of the timer and this should work for you.
Try running the transformer without a timer and see if its still functioning is so get the right timer.
Let me know.


08-22-2010, 06:46 PM
Transformer works fine without it. It's a 120V AC timer, the polarity really shouldn't matter but I guess in this particular combination it does. So, that's why I'm asking what Astro timer will work with an FX transformer.

The Intermatic is upside down in the Unique transformers as well with no problems.

08-22-2010, 08:03 PM

Can you find a link to the exact timer you are attempting to use so I can look at?

08-22-2010, 08:22 PM
This is it - http://www.intermatic.com/products/timers/consumer%20indoor%20timers/digital%20timers/dt620cl.aspx

08-22-2010, 09:14 PM

strange things are happening. I am going to require some more info from you.
You stated in your first post that there was mechanical timers installed prior. Were these two prong timers or three prong? Have you or somebody before you modified anything in the transformer to accomadate the timer upside down?
What are the transfomers fed from? GFCI or normal receptacle? Did your electrician check the polarity at the receptacles that you are plugging the transformers into? Maybe this was reversed all along before you arrived.
Sorry for all the questions but I need to know the exact setup. Changing out the timer with the one you have shown in the link should not be tripping the breaker. Something along the way is not wired correctly.


INTEGRA Bespoke Lighting
08-22-2010, 11:32 PM
Really no point using the intermatic DT620 timers as they consume their expensive on board CR2 batteries very quickly. Also the zone method of determining location is not very accurate. These timers use the on board battery to power the internal relay, as a result they seem to chew through batteries very quickly. Also they are not cold weather rated for those of you in northern climates.

I would suspect that the timer in question has "polarity protection" (one prong is wider than the other and must be plugged into an appropriate socket). By rotating the timer in the receptacle you are reversing the neutral and hot to the timer, hence your problem.

08-23-2010, 12:04 AM
Actually, this plug is not polarity protected and, like I said, it's working just fine in the Unique transformers. Besides with AC power polarity really shouldn't matter, especially for a something solid state like a timer.

Obviously though, it's a problem with this transformer so I'm still looking for an option that will work.

08-23-2010, 09:04 AM
There is an external version of the DT timer available that operated with the same feature set.

I have removed the batteries from a DT 620 and they have stilled continued operating fine as long as power is maintained.

08-24-2010, 05:43 PM
Hey bcg,

Just wondering how you have made out? If you are still looking for a suitable timer I would suggest having your electrician wiring in an Aube astro timer switch back at the breaker panel that controls the GFCI outlet.
Just to clarify the polarity issue. Just lets say that the polarity is reversed. This would then send 120 ac to all the internal neautral wires posing an electrical shock situation depending on how the internal wiring is on the transformer.
Simply put if the intermatic timer was installed in the proper configuration does the main breaker still trip?
Another astro timer available is the Control Scape that was mentioned here:http://www.lawnsite.com/showthread.php?t=325308&page=2

Let me know how you have made out as I am interested in what the problem has been.


08-24-2010, 07:52 PM
Since the DT620 has a ground prong, did you cut it off to spin it around?

08-24-2010, 09:41 PM
Well, sometimes you have to... The transformers are only 2 prong plugs anyway.

We're going to put the outdoor version of the Intermatic between the power plug and the transformer and see if that does it. The 2 DT60's in the Unique timers are going to be replaced with ABT timers with the motion sensor so they can party the night away and not have the lights go out. The FX transformers cover the front yard only, the Unique's are Pool and Spa transformers for the back yard entertaining/pool area.

I should have the outddor timers tomorrow.

08-25-2010, 09:01 AM

I am glad that you have decided to go with another product.
One thing to note and this is coming from an electrician... Do not cut the ground plug off on any device. They are there for a reason and when you cut that safety feature off you are in fact creating an electrical hazard to you and your customers. This is pretty serious stuff my friend and a lot of bad things can happen after you eliminate that safety feature.