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Service Equipment questions

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J

jap

Senior Member
Occupation
Electrician
In my mind all the conductors entering and leaving this disconnect are technically Service Entrance Conductors, and, the 400 and 600 are the Service Disconnects where the bonding and grounding would take place.

I'm sure I'll get corrected.

JAP>
 
tortuga

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
Ok I dusted off some old code books, link fuses were still allowed in the 1930 NEC, by 1935 they were limited to special permission, in 1937 they were limited to special permission and over 600 Amps.

Grouch you could probably argue this either way, but if they are link fuses and your wanting to keep this grandfathered you'd probably need to go by the code that was in effect when it was installed, which my guess is pre 1935, and those old codes would call that the service disconnect.
using any 2020 NEC rules on it I think would bring those suspected link fuse into question.
 
Grouch1980

Grouch1980

Senior Member
Location
New York, NY
Will definitely go with keeping this grandfathered, I don't want to touch it if not necessary, in which case that switch would be following the 1930 NEC.

..... is anyone here from the 1930's??? :)
 
tortuga

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
Grouch1980 said:
Will definitely go with keeping this grandfathered, I don't want to touch it if not necessary, in which case that switch would be following the 1930 NEC.

..... is anyone here from the 1930's??? :)
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No but I have a 1930 NEC :geek: the section on Link fuses is rule 802. It does indicate that the fuses must be visibly stamped with "80% of the maximum current they can carry indefinitely" So i bet if someone carefully cleaned those off you could get some good info.
 
J

jap

Senior Member
Occupation
Electrician
Just be sure you don't reach too far and grab a hand full of B phase when opening the switch.

:)

JAP>
 
H

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
Dennis Alwon said:
I think it could be just a jumper to make the switch non fused. I wouldn't want to change that link if that is what it is.
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Why? Everything would be dead once you opened the switch

Im with Larry on this one. It’s a fusible link
 
B

Barney B

Senior Member
Location
Hurst, TX
Occupation
Electrical Instructor/Trainer
This fused switch was made by the Royal Electrical Manufacturing Co. of Chicago. The fuses are open fuse links which means they were rated over 600A and manufactured before cartridge fuses over 600A became available, which I believe was shortly after World War I. The switch probably qualifies as a service disconnect, but it is not even close to being legal or safe for the reasons listed in prior posts (and others).
 
Grouch1980

Grouch1980

Senior Member
Location
New York, NY
Barney B said:
This fused switch was made by the Royal Electrical Manufacturing Co. of Chicago. The fuses are open fuse links which means they were rated over 600A and manufactured before cartridge fuses over 600A became available, which I believe was shortly after World War I. The switch probably qualifies as a service disconnect, but it is not even close to being legal or safe for the reasons listed in prior posts (and others).
Click to expand...
Amazing. Everyone, thanks for the feedback, this was all great.
 
tortuga

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
I believe Class L fuses are what replaced link fuses. I am not sure when Class L came out, but I think thats why there is a 601 A standard size fuse.
 
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