Has anybody ever had a electronic T8 ballast shock them after it has been disconnected from power and the fixture. I had a ballast zap me when the black and white wires crossed on my hand coming down a ladder. And today I had an LED exit sign do the same thing. Anybody got anything?
Voltage remaining on ballast
- Thread starter dfinz725
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- Placerville, CA, USA
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- Retired PV System Designer
Since the electronic ballast starts by converting AC to DC which is stored/filtered by a capacitor.
That is used to provide controlled current pulses to the tube.
Once the AC is removed and the capacitor only discharges, it may not drop below the threshold voltage of the fluorescent tube. With no other load built in, the capacitor can hold this lower voltage for a long time.
Tapatalk!
That is used to provide controlled current pulses to the tube.
Once the AC is removed and the capacitor only discharges, it may not drop below the threshold voltage of the fluorescent tube. With no other load built in, the capacitor can hold this lower voltage for a long time.
Tapatalk!
rogertaylorlive
Member
- Location
- Mesa
These type of socks are very dangerous....and can cause some serious problems ...beware of them.....:lol::lol:
xformer
Senior Member
- Location
- Dallas, Tx
- Occupation
- Master Electrician
IMHO... Emergency Ballasts are required to be able to illuminate fixtures for 1.5 hours... in a de-energized state. So When the power is disconnected the ballast still has enough stored energy to zap and kill you... Be careful..
K8MHZ
Senior Member
- Occupation
- Electrician
IMHO... Emergency Ballasts are required to be able to illuminate fixtures for 1.5 hours... in a de-energized state. So When the power is disconnected the ballast still has enough stored energy to zap and kill you... Be careful..
I thought it was the sealed lead acid battery in the unit that stored the emergency lighting energy, not a capacitor.
I don't think I have ever seen a capacitor that could deliver an even current and voltage to a load for an hour and a half.
fmtjfw
Senior Member
- Location
- Fairmont, WV, USA
FOR EMERGENCY BALLASTS!!!
FOR EMERGENCY BALLASTS!!!
The emergency ballast with battery backup are often red in color. They commonly appear with a standard ballast and you end up with a lot more wires than in a standard fixture. There will be two wires coming out of the emergency ballast that are connected together, usually with some kind of plastic covered connectors. If you disconnect then, you will defeat the battery backup. DO NOT REMOVE ANY OTHER WIRING (other than commercial power) before disconnecting these. Also note that there may be both switched and unswitched commercial power in the fixture.
If you don't understand the wiring, examine the diagram printed on the emergency ballast carefully.
[I HATE these emergency ballasts, I'm always afraid an unqualified electrician or "handyman" (70E term) is going to get shocked and maybe fall off a ladder working on them.
We had such a guy who often called up ballast manufacturers 'cause he couldn't understand T5 ballasts.]
FOR EMERGENCY BALLASTS!!!
IMHO... Emergency Ballasts are required to be able to illuminate fixtures for 1.5 hours... in a de-energized state. So When the power is disconnected the ballast still has enough stored energy to zap and kill you... Be careful..
The emergency ballast with battery backup are often red in color. They commonly appear with a standard ballast and you end up with a lot more wires than in a standard fixture. There will be two wires coming out of the emergency ballast that are connected together, usually with some kind of plastic covered connectors. If you disconnect then, you will defeat the battery backup. DO NOT REMOVE ANY OTHER WIRING (other than commercial power) before disconnecting these. Also note that there may be both switched and unswitched commercial power in the fixture.
If you don't understand the wiring, examine the diagram printed on the emergency ballast carefully.
[I HATE these emergency ballasts, I'm always afraid an unqualified electrician or "handyman" (70E term) is going to get shocked and maybe fall off a ladder working on them.
We had such a guy who often called up ballast manufacturers 'cause he couldn't understand T5 ballasts.]
Last edited:
- Location
- Massachusetts
Bodines used to be red, now I run into all colors.
Tip offs to me are.
Old one coming out
New parts to go in
Partially installed
Almost done
As was mentioned, look for a connector that unplugs to disconnect the battery, or treat the ballast leads as live.
Tip offs to me are.
- Push to test switches
- Power LEDs
- A lot of extra wiring.
Old one coming out
New parts to go in
Partially installed
Almost done
As was mentioned, look for a connector that unplugs to disconnect the battery, or treat the ballast leads as live.
xformer
Senior Member
- Location
- Dallas, Tx
- Occupation
- Master Electrician
- Occupation
- Licensed Electrician
NO DOUBT!
Nice pics. Thanks for posting.
I noticed your workbench has holder for coffee but none for the cordless. We are 20+ years past the nineties now, I think an upgrade is in order. No reason you should pay for it out of your own pocket though.
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