Young Frankenstein
New member
Hi ya Bean 
glad to see ya
glad to see ya 
Your Electrician Here
- Thread starter Young Frankenstein
- Start date
Young Frankenstein
New member
I concur<a href=showthread.php?s=&postid=15645029#post15645029 target=_blank>Originally posted</a> by BeanAnimal
Attached or detached to the building with the main panel... it makes a difference
Lets just talk about a sub panel in the same building.
for a 120/240V sub panel you MUST have a (4) wire feed. That is (2) hot legs (1) equipment ground and (1) neutral.
The NEUTRAL bar in the SUB panel MUST not be bonded to the ground, ground bar or the panel box housing. It MUST be isolated on its own bus bar. This is a MUST.
You DO NOT have to have a MAIN breaker in the SUB panel, but it is a nice option.
The breaker feeding the sub panel MUST have both poles handle tied. This is a MUST.
The breaker feeding the sub (this should be obvious) must not exceed the rated ampacity of the service cable feeding the sub.
On the other hand, it is perfectly acceptable to oversize the feeder and still use a small breaker set to feed it.
The sub can be fed with copper or aluminum wire.
The sub panels physical location falls under the same rules as a main panel.
Now for an isolated building... things get a bit more complicated due to the grounding rules. Let me know if you need info on that.
"The NEUTRAL bar in the SUB panel MUST not be bonded to the ground, ground bar or the panel box housing. It MUST be isolated on its own bus bar. This is a MUST."
YES! I see a LOT of subpanels with a bonded neutral! While it works, that is electrical power seems fine, it is simply not as safe and the reason there is a code!
The only place the neutral should be bonded is at the main panel (in a residential application).
Oh and I concur about the forum lately Stu!
Glad Fall/ winter is upon us soon so people will hole up and work on their tanks again:hammer:
YES! I see a LOT of subpanels with a bonded neutral! While it works, that is electrical power seems fine, it is simply not as safe and the reason there is a code!
The only place the neutral should be bonded is at the main panel (in a residential application).
Oh and I concur about the forum lately Stu!
Glad Fall/ winter is upon us soon so people will hole up and work on their tanks again:hammer:
BeanAnimal
Premium Member
Yeah I almost fell outa my chair when I read his question... knew it was heading for trouble.
jnarow... you missed a wire. Is the ground hooked to GROUND or NEUTRAL? Or are you only running (1) hot to the sub?
jnarow... you missed a wire. Is the ground hooked to GROUND or NEUTRAL? Or are you only running (1) hot to the sub?
Young Frankenstein
New member
Let me explain the reason you dont bond the neutral in a sub panel just so that you learn.
Only one when the power company loses a neutral in the main feeder, the ground takes over, you simply dont want the neutral going true a sub panel to the ground since its a smaller conductor than the main.
Only one
when the power company loses a neutral in the main feeder, the ground takes over, you simply dont want the neutral going true a sub panel to the ground since its a smaller conductor than the main.
Young Frankenstein
New member
Hi ya Steve
BeanAnimal
Premium Member
Frank, you don't bond the neutral in a sub panel becuase if you do then objectionable current flows through the grounding conductors, defeating their purpose. Furthermore, NEUTRAL current flowing over loose connectors in the grounding system (like an EMT connector) can cause severe heating and/or fire. The size of the "ground" with regard to the "neutral" is not what is at issue. The issue is that the panelboard and other bonded materials will ALWAYS be energized and potentially deadly.
The "grounding cunductor" is actually a bonding conductor and is not meant to carry current. It is meant to keep all points of the system at the same potential with regard to EARTH and the BONDING POINT in the main panel.
The "grounding cunductor" is actually a bonding conductor and is not meant to carry current. It is meant to keep all points of the system at the same potential with regard to EARTH and the BONDING POINT in the main panel.
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Young Frankenstein
New member
I would agree to that also, your right Bean, but most electrical fires start when the power company loses its neutral to your feeder.
nick18tjetta
New member
The outlet behind my tank stopped working. It is the only outlet on the circuit not working and there are not any gfic outlets in the house. I was told if it was a bad outlet other outlets would not work. Do you have any suggestions on what to check?
Thanks
Thanks
BeanAnimal
Premium Member
You have 1 of two problems.
1) you have a failed connection between the malfunctioning receptacle and whatever feeds it
or less likely
2) the receptacle itself has failed
If you are not experienced with electricity this is not a job to tackle yourself.
The first step will entail disconnecting the power to that circuit. The problem is that because the receptacle is dead, you may not know if you removed the power to the circuit.
Once you have ensured power is removed, you will need to removed the receptacle from the housing and check to make sure all of the connections are good. You will also want to check the connections at the upstream receptacle or junction box that feeds power to the dead receptacle.
If you do not find an obvious problem, then things get more complicated. The next step would entail using a meter to check various points in the circuit while it is LIVE. THIS IS NOT SOMETHING A NOVICE SHOULD BE DOING.
Some notes:
Back wired "stab in" connections are very problematic and should never be used! EVER!
NEVER USE STAB INS:
There are SOME receptacles that can be back wired that are NOT "push in" or "stab in" but instead the side screw CLAMPS the wire between two conductive plates. These are perfectly acceptable. These are "camp type" back wire.
The receptacle itself should NOT be used to continue a circuit, the circuit SHOULD be pigtailed to the receptacle.
Like THIS:
NEVER LIKE THIS:
1) you have a failed connection between the malfunctioning receptacle and whatever feeds it
or less likely
2) the receptacle itself has failed
If you are not experienced with electricity this is not a job to tackle yourself.
The first step will entail disconnecting the power to that circuit. The problem is that because the receptacle is dead, you may not know if you removed the power to the circuit.
Once you have ensured power is removed, you will need to removed the receptacle from the housing and check to make sure all of the connections are good. You will also want to check the connections at the upstream receptacle or junction box that feeds power to the dead receptacle.
If you do not find an obvious problem, then things get more complicated. The next step would entail using a meter to check various points in the circuit while it is LIVE. THIS IS NOT SOMETHING A NOVICE SHOULD BE DOING.
Some notes:
Back wired "stab in" connections are very problematic and should never be used! EVER!
NEVER USE STAB INS:
There are SOME receptacles that can be back wired that are NOT "push in" or "stab in" but instead the side screw CLAMPS the wire between two conductive plates. These are perfectly acceptable. These are "camp type" back wire.
The receptacle itself should NOT be used to continue a circuit, the circuit SHOULD be pigtailed to the receptacle.
Like THIS:
NEVER LIKE THIS:
nick18tjetta
New member
Ok, let me see if I get this. If the recepticle is pigtailed then if a receptacle is bad the rest of the circuit will still work.
I am going to check the connections and replace the outlet since they only cost $2, if that doesn't work I guess I will get an pro to check it out, if they don't mind working behind/under a 120 aquarium.
Thanks
I am going to check the connections and replace the outlet since they only cost $2, if that doesn't work I guess I will get an pro to check it out, if they don't mind working behind/under a 120 aquarium.
Thanks
jdoenumber2
New member
How do i check if electronic blue line 400 watt ballast is good with a multi meter?
Any help is greatly appreceated. It flick the bulb when i unplug it.
Any help is greatly appreceated. It flick the bulb when i unplug it.
