The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
Sprinklered equipment 26-008
by bigpapa
12/02/16 04:24 PM
On Delay Relay with Auto Reset
by Potseal
12/01/16 09:59 AM
Wow, that was close!
by jraef
11/28/16 07:06 PM
Earthquake in New Zeeland
by RODALCO
11/27/16 11:25 PM
Calling all Non-US members!! (Non-US only)
by Tjia1981
11/27/16 06:33 AM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 13
HotLine1 9
Texas_Ranger 8
sparkyinak 7
Trumpy 6
Who's Online
1 registered (geoff in UK), 133 Guests and 5 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#51343 - 04/27/05 08:25 PM Voltage drop
Dave55 Offline
Member

Registered: 05/08/04
Posts: 666
Loc: Crystal Lake, Illinois, USA
I installed a Juno transformer for 5 puck-type undercabinet lights. The secondary of the transformer is 13.8 volts. I'd like to drop it to 11.8 volts for bulb life. Can I add a resistor or something else. If so what size & where will I find it. Thanks.

Dave

Top
Work Gear for Electricians and the Trades

Work Gear for Electricians and the Trades
Work Gear for Electricians and the Trades
Arc Flash Clothing, Gloves, KneePads, Tool Belts, Pouches, Tool Carriers, etc. etc....

#51344 - 04/27/05 11:00 PM Re: Voltage drop
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
How many watts per light?
_________________________
Greg Fretwell

Top
#51345 - 04/28/05 04:59 AM Re: Voltage drop
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
Dave is that voltage measured under load or by the open-circuited secondary winding?.
2V is a fair bit to "drop" in a case like this and I don't personally think a resistor would be suitable for this sort of application.
Any power "lost" would be dissipated as heat.
I'm assuming you are using fittings with the small Halogen burner lamps in them, if they are 12V lamps, should it make any difference?.
I was under the impression that these lamps have a reasonably short life anyway.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin

Top
#51346 - 04/28/05 12:42 PM Re: Voltage drop
Sandro Offline
Member

Registered: 12/30/01
Posts: 449
Loc: Stoney Creek, ON, Canada
Place the XFMR in a remote location and you get your VD.

Top
#51347 - 04/28/05 03:04 PM Re: Voltage drop
Active 1 Offline
Member

Registered: 02/22/03
Posts: 684
Loc: Grayslake IL, USA
Hey Dave,
Some of those Juno electronic transformers burn out faster than the bulbs.

I have almost lost a good customer over them puck light because of short bulb life. The customer had 50-75 of them done by cabnet people. Could not be dimmed easily because they were on the same switch other types of lights. They kept them on all day and 1/2 the night. Customer was angry because we came out every 8 weeks to change bulbs or pucks.

Besides the transformers and bulbs going bad sometimes the bulb sockets make a bad connection to the bulb.

My advice stay away from pucks and use under cabnet lights with 120v bulbs. Also Juno trac 12 or similar with magnetic transformers is good.

Tom

Top
#51348 - 04/28/05 05:36 PM Re: Voltage drop
Electric Eagle Offline
Member

Registered: 04/20/02
Posts: 928
Loc: Alpharetta, GA
Just add about 15 ft of wire and you'll easily lose those pesky extra volts.

Is your measurement at the transformer or at the Pucks?

Top
#51349 - 04/28/05 06:25 PM Re: Voltage drop
Dave55 Offline
Member

Registered: 05/08/04
Posts: 666
Loc: Crystal Lake, Illinois, USA
Thanks guys. The lights are five 20 watt halogen pucks. I measured it with the open secondary. The customer says the lights are noticably brighter, and the Juno trancformer is a magnetic 1500 watt. It had an additional wire for the primary to boost the voltage if needed.

Dave

Top
#51350 - 04/29/05 03:15 AM Re: Voltage drop
Active 1 Offline
Member

Registered: 02/22/03
Posts: 684
Loc: Grayslake IL, USA
Are you sure it's not a 150w transformer?

With a load the it's probibly fine. Just tell the customer they have a better transformer now. If they want it dimmed sell them a magnetic dimmer.

Tom

Top
#51351 - 04/29/05 12:28 PM Re: Voltage drop
LearJet9 Offline
Member

Registered: 04/24/05
Posts: 196
Loc: Millis, MA USA
Active - Please!! Bite your tongue. We have several commercial customers that use dozens of those Alexandra or WAC puc lights in thier stores. We are at one store or another once or twice a week for lamp/puc replacement. I hope they dismiss your suggestion as silly. Let's keep those beautiful puc lights!!
Bill

Top



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals