Primary Injection Minimum Breaker Size As Per NETA

[dnigra]

Hey All.

Regarding Primary Injection with respect to Insulated Case/Molded Case and L.V Power Breakers...I have not found a spec detailing if there is a minimum size breaker to test. For a few projects, specific documentation stated 400A and above. Does anyone have further insight?

Thank you.

Dan Nigra
EPST
NJ

[SecondGen]

Hey All.

Regarding Primary Injection with respect to Insulated Case/Molded Case and L.V Power Breakers...I have not found a spec detailing if there is a minimum size breaker to test. For a few projects, specific documentation stated 400A and above. Does anyone have further insight?

Thank you.

Dan Nigra
EPST
NJ

I don't think there is a standard that talks about a minimum size, I've actually been on jobs where we had to test 1P 20A breakers in panels. It all comes down to the specific project if I'm not mistaken, most common specs I've seen call for 100A and above, 250A and above, or 400A and above.

[dnigra]

I don't think there is a standard that talks about a minimum size, I've actually been on jobs where we had to test 1P 20A breakers in panels. It all comes down to the specific project if I'm not mistaken, most common specs I've seen call for 100A and above, 250A and above, or 400A and above.

Yes..I have been on jobs where i was required to test every breaker..1 pole 15 am and above...and provide trip curve data in the test form. what a pain in the butt. Megger SPI225 works for this!

TY

[Kalbi_Rob]

Hey All.

Regarding Primary Injection with respect to Insulated Case/Molded Case and L.V Power Breakers...I have not found a spec detailing if there is a minimum size breaker to test. For a few projects, specific documentation stated 400A and above. Does anyone have further insight?

Thank you.

Dan Nigra
EPST
NJ

NETA only references you to the manufacturer's recommendations and NEMA AB4.

NEMA AB4 does not state a minimum, but per Table 1, breakers rated 15A or less should be tested with a 14 AWG cable or larger.

Most companies set minimum test value of 400A for salesman to use for primary testing as they are the least likely to have any damage to the breaker due to Primary Injection. I've seen other companies state 250A, but most customer specifications call for 100A and above due to SCCS requirement for insurance purposes.

I've also been on sites testing 10A and above due to insurance claims, or an engineer thinks it is beneficial.

[AaronCBI]

Hey All.

Regarding Primary Injection with respect to Insulated Case/Molded Case and L.V Power Breakers...I have not found a spec detailing if there is a minimum size breaker to test. For a few projects, specific documentation stated 400A and above. Does anyone have further insight?

Thank you.

Dan Nigra
EPST
NJ

I am a testing technician at a company that specializes in circuit breakers, and the techs who deal with molded case and small breakers will do primary injection on even the smallest of single pole breakers. We have a baby primary set that outputs <200A.
I dont believe they use a DLRO on them though.

[AaronCBI]

I am a testing technician at a company that specializes in circuit breakers, and the techs who deal with molded case and small breakers will do primary injection on even the smallest of single pole breakers. We have a baby primary set that outputs <200A.
I dont believe they use a DLRO on them though.

I could be wrong about DLRO on them. I don't really work on molded case breakers.

[michaellabeit]

Hey All.

Regarding Primary Injection with respect to Insulated Case/Molded Case and L.V Power Breakers...I have not found a spec detailing if there is a minimum size breaker to test. For a few projects, specific documentation stated 400A and above. Does anyone have further insight?

Thank you.

Dan Nigra
EPST
NJ

I've run tests on 40A breakers as demonstrations with a Megger INGVAR. In principle, I don't see why there would need to be a minimum amperage, so I think you're good.