code violation on secondary.

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grumpy11

Senior Member
all i did was install 1 30kva transformer feeding a panel
with 1 3pole 100 1 2pole 100
5 -1 pole 20.
yes i know thats wrong.
but he quoted 450.3 b.2

then he hits me with 250.21c.
disconnect not provided coduit in 25ft of secondary transformer feed.
now 250.21c does not say that

this is 2005 code.

l
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
More details are needed.

Primary voltage
Primary protective device size
Primary conductor size

Secondary voltage(s)
Secondary protective device size
Secondary conductor size
Secondary conductor length to protective device

450.3(b) is about sizing the primary protective device, and 240.21(C) is about protecting the secondary conductors. These are related, but separate, issues.
 

grumpy11

Senior Member
cdoe violation

cdoe violation

pv= 480 3 phase
pv ocp 50 amp
wire size #6

sv=208 3 phase 4 wire 120/208
sv ocp 100 amp
wire size #2
length 50 ft +
 

russ

Senior Member
Location
Burbank IL
then he hits me with 250.21c.
disconnect not provided coduit in 25ft of secondary transformer feed.
now 250.21c does not say that

this is 2005 code.
chances are that's a typo. He probably meant 240.21c
 

grumpy11

Senior Member
code violation

code violation

found answer to 240.21.
any help on the first one 450.3 b 2
little confused on this one
 

david luchini

Moderator
Staff member
Location
Connecticut
Occupation
Engineer
any help on the first one 450.3 b 2
little confused on this one

Read Table 450.3(B), Note #2.

You indicated that you have more than six circuit breakers, and the total of the circuit breakers exceeds the allowed value of a single circuit breaker.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
pv= 480 3 phase
pv ocp 50 amp
wire size #6

sv=208 3 phase 4 wire 120/208
sv ocp 100 amp
wire size #2
length 50 ft +

Under 240.21(c) your conductor length is limited to 25' max before you 'hit' your protective device.

I see no violation under 450.3(b). Your primary protective device can exceed 45A (1.25 X pri FLA) because your secondary protective is not more than 103A (1.25 x sec FLA).
 
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