Landscape lighting transformer keeps tripping circuit

Reply

  #1  
Old 02-03-17, 05:05 PM
Member
Thread Starter
Join Date: Jan 2002
Location: MO
Posts: 179
Received 0 Votes on 0 Posts
Landscape lighting transformer keeps tripping circuit

I have a toroidal 1200W multitap landscape transformer servicing 5 circuits of approximately fifty 3-5W LED fixtures. It is on a dedicated circuit. I had a 20A AF-GFCI breaker that tripped fairly frequently when the circuit switches on. I replaced it with a regular breaker. It still trips, but less frequently.

It only trips when switching ON. Once on it stays on fine, and does not trip when switching OFF.

Not related to rain, moisture or weather.

The five circuits are all between 30-150ft 12G landscape wire. Probably much more copper than needed.


What could be causing this? Could there be an initial current surge beyond 20A.? If it is a "short" somewhere, why does it stay on, once it is on??

Thanks!
 

Last edited by boonjh; 02-03-17 at 06:19 PM.
Sponsored Links
  #2  
Old 02-03-17, 05:09 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 54,577
Received 510 Votes on 480 Posts
A transformer has a primary winding and a secondary winding.
The power gets connected to the primary and the lights to the secondary.

There should not be any interaction between the primary and secondary which means nothing on the low voltage side can cause the GFI to trip.

There is a small chance that the transformer you are using has one leg of the secondary grounded. That would be something to look into. A make and model could help to clear up that point.

I see that a regular breaker is tripping too. That wouldn't be affected by a grounded secondary line. The total load on the transformer is roughly 250 watts ?
 
  #3  
Old 02-03-17, 06:18 PM
Member
Thread Starter
Join Date: Jan 2002
Location: MO
Posts: 179
Received 0 Votes on 0 Posts
That is correct.

I was wondering if all the copper in those parallel circuits could present such a low resistance initially, acting as a "sump" and draw too much current??? Wild guess......But then, these are designed for it.

Model is TR 1200-1222 (I think it represents 1200W from four 300W circuits) and 1222 represents the different taps from 12V-22V.

Thanks
 
  #4  
Old 02-03-17, 07:58 PM
Member
Join Date: Mar 2010
Location: USA
Posts: 3,756
Received 42 Votes on 40 Posts
All that copper in those 12 gauge parallel circuits would not act as a sump and cause a brief high currnt draw. But you would need to keep all that copper to minimize voltage drop that could cause the lights at the far ends of the low voltage circuits circuits to be dimmer or to flicker.

You might want to get a clamp on ammeter to verify how much current you are really drawing.
 
  #5  
Old 02-03-17, 08:05 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 54,577
Received 510 Votes on 480 Posts
I recognize that transformer. I haven't sen that problem in the past.
I can understand an arc fault breaker tripping but not a standard 20A breaker.

I'm wondering if an HVACR circuit breaker would work without tripping.
I'm also wondering if this problem is related to the LED vs incandescent lamps.

I think I'd check with the manufacturer and see if they can shed any light on the problem.
Lightcraft outdoor/uploads/TR-1200-1222-SS.pdf
 
  #6  
Old 02-21-17, 06:01 PM
Member
Thread Starter
Join Date: Jan 2002
Location: MO
Posts: 179
Received 0 Votes on 0 Posts
I measured the current at the circuit breaker: 1.4Amp.

I have not spoken to the manufacturer yet
 
  #7  
Old 02-21-17, 08:32 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 54,577
Received 510 Votes on 480 Posts
The LED's can be like a dead short across the transformer until they illuminate.
You'd need a peak reading probe that locked the startup surge value.

I had checked to see if it says "incandescent only" and I didn't see it but the manufacturer may have different info that could be helpful.
 
  #8  
Old 02-22-17, 08:19 AM
Member
Thread Starter
Join Date: Jan 2002
Location: MO
Posts: 179
Received 0 Votes on 0 Posts
I spoke to manufacturer. This transformer is fine with LED's. It is an AC tranformer, and my lamps are AC and DC rated. He did not seem worried about number of LED's either.

His only suggestion was to place the entire load on just one or two of the transformer circuits, rather than spreading it over all four circuits.

I will update you!
 
  #9  
Old 02-23-17, 10:48 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,280
Received 43 Votes on 35 Posts
I had a 20A AF-GFCI breaker that tripped fairly frequently when the circuit switches on.
That would be a dual function AFCI/GFCI breaker, what code were you trying to meet? Are you in the Kansas City area?

boonjh
I measured the current at the circuit breaker: 1.4Amp.
I think it's safe to say the breaker was not tripping on overload. You could have a bad dual function breaker.



I saw my first dual function AFCI/GFCI receptacle last week.
 
  #10  
Old 02-23-17, 10:58 AM
Member
Thread Starter
Join Date: Jan 2002
Location: MO
Posts: 179
Received 0 Votes on 0 Posts
No, This is happening with a regular 20A breaker.

(I was looking for a GFCI breaker to protect the outside receptacle....... I prefered it to using an outside GFCI outlet. The dual function breaker is much lower price. Figured having arc fault protection won't hurt??)
 
  #11  
Old 02-23-17, 11:10 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: United States
Posts: 10,280
Received 43 Votes on 35 Posts
A regular breaker will trip on overload or a direct short. If you correctly measured the current draw the breaker isn't overloaded.
 
  #12  
Old 05-09-17, 03:14 PM
Member
Thread Starter
Join Date: Jan 2002
Location: MO
Posts: 179
Received 0 Votes on 0 Posts
My working diagnosis is that the sudden current inflow to energize the transformer, causes the breaker to trip. (I have isolated the different load circuits on the transformer, without any luck)

My question is: could a "time delay breaker" fix the problem? (I have a panel that uses "SquareD" breakers)
 
  #13  
Old 05-09-17, 09:23 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 54,577
Received 510 Votes on 480 Posts
From Schneider Industries.....

QO-HM high-magnetic circuit breakers are recommended for area lighting (such as
athletic fields, parking lots, and outdoor signs), when using lamps of inherent high inrush current, individual dimmer applications or other applications where high inrush currents exceed standard tripping conditions. These circuit breakers are available in one-pole 15 and 20 A ratings only. QO-HM circuit breakers are physically interchangeable with standard QO circuit breakers and accommodate the complete range of QO accessories.
QO-HM circuit breakers are manufactured with the magnetic trip point calibrated at a
much higher level than standard QO circuit beakers.

That would be a QO120HM breaker. You may have to get it at an electrical supply house.
I'm not sure the home improvement stores carry them.

Square D (Schneider Electric) QO120HM High Magnetic HACR-Type 20A 120/240V Breaker
 
  #14  
Old 05-13-17, 08:40 AM
Member
Thread Starter
Join Date: Jan 2002
Location: MO
Posts: 179
Received 0 Votes on 0 Posts
Thanks PJMax

My electric panel only accepts the "homeline" squareD type breakers.

Do you perhaps know if there is such a breaker?
 
  #15  
Old 05-13-17, 08:51 AM
Member
Thread Starter
Join Date: Jan 2002
Location: MO
Posts: 179
Received 0 Votes on 0 Posts
I assume it is the HOM120HM
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: