Trade Terms that should go away

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electricman2

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Location
North Carolina
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Retired Electrical Contractor
celtic said:
No way.... the look on a person's face when you say "I'd be happy to check your shorts" is priceless :grin::grin::grin:

Actually saw this on an EC's van once "Let us check your shorts"
 

charlie b

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Lockport, IL
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kc8dxx said:
I work with hydraulics on occasion. Normally Open in the Hydraulics world means the oil is flowing. Normally Open in the Electrical world means the electrons are not flowing. Drives me nuts.:grin:
The first question I ask an engineer that I just met is this: "When you open something, does it cause flow or prevent flow?" That way, I can tell if I am talking to an Electrical Engineer or a Mechanical Engineer. :grin:
 

charlie b

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Lockport, IL
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electricman2 said:
Actually saw this on an EC's van once "Let us check your shorts"
If you buy an NEC-related book from Mike Holt, you will get a free sticker containing the text of "Charlie's Rule." It also has a sketch of a person reading an NEC book, and wearing a shirt with the text, "Electrician, qualified to remove your shorts." You may credit me with "Charlie's Rule," but do not credit me with (or blame me for) the art work.
 

charlie b

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Lockport, IL
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Retired Electrical Engineer
(Replying to my comment about "normally open":
stickboy1375 said:
What else would you call something that is normally in a certain position?
My problem is with the word "normal." If you have two pumps, and switch from one to the other every other day, which one is "normally on"? If a valve is open when pumping water to one tank, and is closed when pumping to another tank, is the valve "normally open" or "normally closed"? If a switch has a contact that is open, when the switch is "off," and closed, when the switch is "on," and if the "usual" (I won't say "normal" in this context) condition of the system is for this switch to be "on" for 99.999% of the time, is that contact "normally open" or "normally closed"?
 

John Valdes

Senior Member
Location
SC.
Occupation
Retired Electrician
Charlie, Now I know why you had me remove my signature. You thought I was stealing Mikes line.....lol
 

GeorgeB

ElectroHydraulics engineer (retired)
Location
Greenville SC
Occupation
Retired
charlie b said:
Highest on my list would be the phrases "normally open," normally closed," and anything similar.

I'm in electrohydraulics ... we like "normally passing", "normally blocking".

An open valve or closed contact passes
A closed valve or open contact blocks
 

charlie b

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Location
Lockport, IL
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Retired Electrical Engineer
GeorgeB said:
An open valve or closed contact passes, a closed valve or open contact blocks
Yea, that part I might have guessed. :roll:

But if a system can be operated in many different ways, and if all of them are considered "normal" operations (not "abnormal" or "emergency situations"), which of the operating modes do you choose, in order to say that the position of a valve during that operating mode is the one you will call the "normal position" of the valve? It's all about the meaning of "normal."

I prefer the notation of "a" and "b" contacts. An "a contact" is one that is open, when the device (relay, switch, whatever) is in the mail on its way to your facility (i.e., unopened box, no wires attached, de-energized state). If you install a relay in an application that keeps it energized for most of its operating life, and if therefore its "a contacts" are closed for most of their operating lives, the "a contacts" are still called "a contacts." I don't like the confusion that would arise if you instead called them "normally open contacts," and then explained that they are "normally" kept closed.
 

John Valdes

Senior Member
Location
SC.
Occupation
Retired Electrician
I just look at the relay configuration to see what is NO and NC. It's always on the relay. I have actually remembered the config for C-Form relays 8 and 12 pin due to the many I have installed. But "normally" is a bit ambiguous. But normally, is refering to (not energized). Unless noted on the relay I have found this to be true.
 

stickboy1375

Senior Member
Location
Litchfield, CT
charlie b said:
(Replying to my comment about "normally open":
My problem is with the word "normal." If you have two pumps, and switch from one to the other every other day, which one is "normally on"? If a valve is open when pumping water to one tank, and is closed when pumping to another tank, is the valve "normally open" or "normally closed"? If a switch has a contact that is open, when the switch is "off," and closed, when the switch is "on," and if the "usual" (I won't say "normal" in this context) condition of the system is for this switch to be "on" for 99.999% of the time, is that contact "normally open" or "normally closed"?

Normal is the condition of the device before a voltage is applied... the way I look at it anyway...
 

kc8dxx

Senior Member
Location
Ohio
charlie b said:

The first question I ask an engineer that I just met is this: "When you open something, does it cause flow or prevent flow?" That way, I can tell if I am talking to an Electrical Engineer or a Mechanical Engineer. :grin:

LMAO! :grin:
 

charlie b

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Location
Lockport, IL
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Retired Electrical Engineer
John Valdes said:
But ?normally? is referring to ?not energized.? Unless noted on the relay I have found this to be true.
stickboy1375 said:
Normal is the condition of the device before a voltage is applied... the way I look at it anyway...
I agree with this interpretation. But I have found that I cannot always trust my listener to interpret it the same way. Others have interpreted ?normal? as meaning the state the device can be found in, if you were to look at it while the system is operating in its usual manner.

The way I handle the situation is that I automatically cringe, whenever I hear the word ?normally? used in the context of ?normally open.? I stop and ask the person to clarify the intended meaning of ?normally.? It is only one of many ?cringe words and phrases.? I get the same reaction when someone tells me ?I am working on it,? or ?It?s on the way,? or worst of all, ?As far as I know.?
 

stickboy1375

Senior Member
Location
Litchfield, CT
charlie b said:


I agree with this interpretation. But I have found that I cannot always trust my listener to interpret it the same way. Others have interpreted ?normal? as meaning the state the device can be found in, if you were to look at it while the system is operating in its usual manner.

The way I handle the situation is that I automatically cringe, whenever I hear the word ?normally? used in the context of ?normally open.? I stop and ask the person to clarify the intended meaning of ?normally.? It is only one of many ?cringe words and phrases.? I get the same reaction when someone tells me ?I am working on it,? or ?It?s on the way,? or worst of all, ?As far as I know.?

This is an interesting topic, I guess I'm just normally used to buying a SPDT contactor unenergized and going by the way the contacts are labeled... :grin:
 

John Valdes

Senior Member
Location
SC.
Occupation
Retired Electrician
It is quite ambiguous to call 0-600 volts, low voltage even though it is considered that way.
 

charlie b

Moderator
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Location
Lockport, IL
Occupation
Retired Electrical Engineer
John Valdes said:
It is quite ambiguous to call 0-600 volts, low voltage even though it is considered that way.
Not to everyone. Those involved in fire alarm and security systems will call 120 volts "high voltage," and call their own power supplies "low voltage." So you are right to say it is ambiguous.
 

tom baker

First Chief Moderator
Staff member
I'll recap
1. Low Voltage
2. Subpanel
3. Ground wire
4. High Voltage
5. Common

Re the NO or NC, there is NEMA uses form A, B, C for relay contacts.
But the drawings should state relay contacts shown in deenergized condition
 

Jljohnson

Senior Member
Location
Colorado
As far as the NO/NC issue, I always refer the "Normal" as the state the contact was or would be in if you took it out the manufacturer's box 5 seconds ago. Helps me to get whoever I'm talking to and me on the same page. blueprint term I'd like to see dissapear would be "By Others" Who are "others" and why are they responsible for such a large portion of today's construction projects? Considered naming a company "Others Electric" once.
 

John Valdes

Senior Member
Location
SC.
Occupation
Retired Electrician
How about:

Low Voltage
Medium Voltage
High Voltage

Safety labels on panels and equipment sometimes warn of high voltage. But it's 480....lol
 
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