Wire Termination Reducer

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ramIII

Member
Location
virginia
We have a project that called for 20 amp lighting contactors with lugs that have #10 maximum conductor size. Because of distance the wire size is #8. We had planned on using a #8 to #10 wire termination reducer at the contactors but the electrical engineer said we would need to go to a larger contactor with larger lugs because the wire reducer would choke down the electricity and defeat the purpose of over sizing the wire. Just would like to hear some thoughts.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
We have a project that called for 20 amp lighting contactors with lugs that have #10 maximum conductor size. Because of distance the wire size is #8. We had planned on using a #8 to #10 wire termination reducer at the contactors but the electrical engineer said we would need to go to a larger contactor with larger lugs because the wire reducer would choke down the electricity and defeat the purpose of over sizing the wire. Just would like to hear some thoughts.

My first guess would be he is just making fun.
 

Carultch

Senior Member
Location
Massachusetts
We have a project that called for 20 amp lighting contactors with lugs that have #10 maximum conductor size. Because of distance the wire size is #8. We had planned on using a #8 to #10 wire termination reducer at the contactors but the electrical engineer said we would need to go to a larger contactor with larger lugs because the wire reducer would choke down the electricity and defeat the purpose of over sizing the wire. Just would like to hear some thoughts.

I've never heard of that being an issue. What exactly does the engineer mean by "choke"?

It is true that the reducers have a local resistance and possibly reactance that adds to the voltage drop issues above what wire length alone does, but I can't understand it being any more of an inductor than the wire. Usually "choke" informally refers to the behavior of an inductive component (inductor or the parasitic inductive effect of wire and metal conduit) that adds "electrical inertia" to the flow of current.
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
We have a project that called for 20 amp lighting contactors with lugs that have #10 maximum conductor size. Because of distance the wire size is #8. We had planned on using a #8 to #10 wire termination reducer at the contactors but the electrical engineer said we would need to go to a larger contactor with larger lugs because the wire reducer would choke down the electricity and defeat the purpose of over sizing the wire. Just would like to hear some thoughts.

Surely, as an engineer, he must be joking with you as petersonra said. I've had electricians make statements like this if they are not well trained but certainly not an E.E.
Just wire nut a pigtail of #12 to the #8 in the contactor enclosure or transition to #12 at a near by J-box and move on.
 

kwired

Electron manager
Location
NE Nebraska
Surely, as an engineer, he must be joking with you as petersonra said. I've had electricians make statements like this if they are not well trained but certainly not an E.E.
Just wire nut a pigtail of #12 to the #8 in the contactor enclosure or transition to #12 at a near by J-box and move on.
But then the #12 would become the choke:D

If this guy was not joking it is time to educate him on a few things. Start by asking him just how much voltage drop will be across the reducing device in question, even a ballpark figure to start with if he don't have the time to figure it out right now. Even if it dropped just a half volt and the load were say 15 amps, that is about 7.5 watts that connection will give up as heat. That is a lot of heat on that small of an area, I have a 7 watt soldering iron.
 

luckylerado

Senior Member
We have a project that called for 20 amp lighting contactors with lugs that have #10 maximum conductor size. Because of distance the wire size is #8. We had planned on using a #8 to #10 wire termination reducer at the contactors but the electrical engineer said we would need to go to a larger contactor with larger lugs because the wire reducer would choke down the electricity and defeat the purpose of over sizing the wire. Just would like to hear some thoughts.

:happysad: Just write a big fat change order.
 

dkidd

Senior Member
Location
here
Occupation
PE
He was not joking. This was from an EE for a VDOT project. I am not even sure how to respond without insulting the guy.

If he's with VDOT, he probably thinks it's like having a six-lane highway necked down to a single lane.
 

kwired

Electron manager
Location
NE Nebraska
If he's with VDOT, he probably thinks it's like having a six-lane highway necked down to a single lane.
And it is, but there is only a limited amount of traffic and one lane can handle it pretty well in this instance. If you increased the load you then would start to get more bottleneck in the traffic at that point.
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
He was not joking. This was from an EE for a VDOT project. I am not even sure how to respond without insulting the guy.

Yep, these can be messy calls to make. Sometimes it's better to just grin and bear it as long as it does not create a hazard or serious code violation, especially if it can have negative repercussions on the job or business relationship. That said, at least for me, as I have grown much older I find myself much less tolerant of this kind of crap and would probably call BS just on principal-especially with someone who should know better such as an E.E. or an inspector.
At least in this case it is harmless what he wants.
 

ramIII

Member
Location
virginia
Yep, these can be messy calls to make. Sometimes it's better to just grin and bear it as long as it does not create a hazard or serious code violation, especially if it can have negative repercussions on the job or business relationship. That said, at least for me, as I have grown much older I find myself much less tolerant of this kind of crap and would probably call BS just on principal-especially with someone who should know better such as an E.E. or an inspector.
At least in this case it is harmless what he wants.

If it were a code violation I would definitely bring something like that to his attention. We only need to change one contactor. Since we are in submittal approval process my gear supplier is doing it at no cost. I'll probably just let it be on this one but am a little concerned of what else he may come up with since the project is just coming out of the ground.
 
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