To anyone who can help.Example, a landscape lighting transformer 120 primary 24 volts secondary, whitch of the two leads on secondary is the hot? which is the neutral? and why dont i need to pay attention when i wire each landscape light?Do you have diagrahms please.And if only a few millivolts can be fatal to some why is 50 or 24 volts not considerd dangerous? Second question,why do i get shocked off a neutral coming back to the panel when a load is on at the receptacle that the neutral is coming from?isnt the voltage already used at the load? if not how much voltage is returning on the neutral from the load? diagram please, this will clearup alot for me thankyou,
troubled transformer
- Thread starter bond
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- Massachusetts
Re: troubled transformer
There is no neutral on the secondary of this transformer and with both of them ungrounded neither one is 'hot'.
Because it does not matter with AC current and incandescent lamps.
I think you mean a few milliamps.
No, the voltage is not used up, when you get a shock this way you are using your body as a conductor to run the load.
bphgravity
Senior Member
- Location
- Florida
Re: troubled transformer
I would first suggest you read up on basic electrical theory as you have some misconceptions about how electricity works.
1. The secondary circuits of a low-voltage lighting system are not grounded, however the manufacturer may provide labeling or other identification to identify the circuit "polarity".
2. Voltage is generally considered lethal at about 40V. This is why low-voltage systems are limited to 30V max per the NEC. It takes a few mA to kill someone not mV.
3. Voltage isn't "used" by loads. It provides the pressure on the system to allow current to flow. Generally, there should be no potential between yourself and the "neutral" conductor, as it is grounded. However, if the neutral is opened, it effectively becomes an ungrounded conductor, and a potential will exist between you and any grounded object. Or, you can become in parallel with the neutral conductor and receive a lethal shock if the contact resistance is sufficently low enough to allow a few mA to flow through your body.
I would first suggest you read up on basic electrical theory as you have some misconceptions about how electricity works.
1. The secondary circuits of a low-voltage lighting system are not grounded, however the manufacturer may provide labeling or other identification to identify the circuit "polarity".
2. Voltage is generally considered lethal at about 40V. This is why low-voltage systems are limited to 30V max per the NEC. It takes a few mA to kill someone not mV.
3. Voltage isn't "used" by loads. It provides the pressure on the system to allow current to flow. Generally, there should be no potential between yourself and the "neutral" conductor, as it is grounded. However, if the neutral is opened, it effectively becomes an ungrounded conductor, and a potential will exist between you and any grounded object. Or, you can become in parallel with the neutral conductor and receive a lethal shock if the contact resistance is sufficently low enough to allow a few mA to flow through your body.
hbiss
EC, Westchester, New York NEC: 2014
- Location
- Hawthorne, New York NEC: 2014
- Occupation
- EC
Re: troubled transformer
...whitch of the two leads on secondary is the hot? which is the neutral?
Since the secondary is not grounded there is no hot or neutral. Connect them in any way you wish to the lights.
And if only a few millivolts can be fatal to some why is 50 or 24 volts not considerd dangerous?
Generally because of high skin resistance it would be difficult (should say less likely) for enough current to flow because of the low voltage. By the way, its a few milliamps not millivolts.
Why do i get shocked off a neutral coming back to the panel when a load is on at the receptacle that the neutral is coming from?
If I understand your question you have disconnected the neutral at the panel. There will be 120 volts between the disconnected neutral and ground or the neutral bus because the circuit is completed by the load plugged into the receptacle. Current will flow from the breaker, through the load which is a low resistance to the neutral. You can consider that the load is not even there and imagine a single wire running from the breaker to the receptacle and back to the panel.
-Hal
...whitch of the two leads on secondary is the hot? which is the neutral?
Since the secondary is not grounded there is no hot or neutral. Connect them in any way you wish to the lights.
And if only a few millivolts can be fatal to some why is 50 or 24 volts not considerd dangerous?
Generally because of high skin resistance it would be difficult (should say less likely) for enough current to flow because of the low voltage. By the way, its a few milliamps not millivolts.
Why do i get shocked off a neutral coming back to the panel when a load is on at the receptacle that the neutral is coming from?
If I understand your question you have disconnected the neutral at the panel. There will be 120 volts between the disconnected neutral and ground or the neutral bus because the circuit is completed by the load plugged into the receptacle. Current will flow from the breaker, through the load which is a low resistance to the neutral. You can consider that the load is not even there and imagine a single wire running from the breaker to the receptacle and back to the panel.
-Hal
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