I am installing a light fixture that has 2 - 200 watt 120 volt to 12 volt magnetic transformers that feed 20 - 10 watt quartz lamps. the 2 secondaries of the transformers are tied in paralel like the manufacturer is making 1 - 400 watt tranformer. When the power was turned on 1 transformer smoked. My experience with transformers tells me that the 2 secondaries cannot be tied together, am I correct? I realize I only need 1 200 watt transformer for this job but the the manufacturer has noted there is a 20 watt max. on lamp size.
low voltage lighting
- Thread starter koby
- Start date
- Status
- Location
- Massachusetts
Transformers secondaries can be tied together.
They will have to be 'in phase' with each other.
They will have to be 'in phase' with each other.
tallgirl
Senior Member
- Location
- Glendale, WI
- Occupation
- Controls Systems firmware engineer
iwire said:
Can be, or should be? If they are connected in-phase and some unsuspecting person disconnects one of the primaries, they now have a 120v back-fed hot transformer in their hands.
Yeah, yeah, I know -- Turn Stuff Off First, but it still strikes me as an accident waiting to happen.
(And of course, if they are no connected in phase then one of them is likely to get smoked ...)
- Location
- Massachusetts
Holy lost souls Batman...look who came back. :grin:
It sounded to me like factory wiring and they can pretty much do what they want.
My own choice would be no.
tallgirl said:
It sounded to me like factory wiring and they can pretty much do what they want.
My own choice would be no.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
iwire said:
Or it was connected by someone else and brought back as a defect. All the LV lighting trany's I have seen give 300 watt max on each terminal. You can get 300, 600 or 900 watt tranys with respectively, 1, 2, 3 sets of terminal screws.
I wonder if was meant to be wired like that or a screw up along the way somewhere
WB Tallgirl
- Location
- Massachusetts
Dennis Alwon said:
What I was saying is that it was not the OP that decided to parallel the transformers but the factory.
Obviously there was a defect....smoke came out.:grin:
That is the maximum the NEC allows per LV circuit. But a manufacturer is not bound by the NEC.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Why not divide the load into two groups and put half on each transformer?
Nice to have you back, Julie.
Nice to have you back, Julie.
- Status