20A Homeline Breaker tripping with compressor

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tom baker

tom baker

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If the compressor is on a dedicated 20 A circuit the CB can be replaced with higher A rating.
Whats the Hp of the motor?
Or is it one of those non-HP rated motors, in that case whats the motor amps?
 
don_resqcapt19

don_resqcapt19

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Jim,
I did have one that would trip if pluged into receptacle but add 100 foot #16 cord and ran fine
Click to expand...
The cord acts as a simple reduced voltage starter and limits the current so the breaker doesn't trip on starting.
Don
 
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Lxnxjxhx

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20A Homeline Breaker tripping with compressor

The breaker's current vs. time curve should allow for normal compressor current surge but trip at fault currents. This is usually plotted as a logarithmic scale for time and a linear scale for current.
The compressor people can probably recommend a suitable breaker part number with a current-time curve that is tailored to this application.
If you have an oscilloscope with storage capability and a current sensing resistor you can view the compressor's startup current. Switching power supplies (like in computers) without "soft start" are especially hard on breakers, and will fuse switch contacts because of their enormous start-up current.
 
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Energize

Energize

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Milky Way Galaxy
langjahr@comcast.net said:
The breaker's current vs. time curve should allow for normal compressor current surge but trip at fault currents. This is usually plotted as a logrithmic scale for time and a linear scale for current. The compressor people can probably recommend a suitable breaker part number.
If you have an oscilloscope with storage capability and a current sensing resistor you can view this curve.
Switching power supplies are especially hard on breakers, and will fuse switch contacts because of their enormous start-up current.
Click to expand...

Where is Marc with all his tools when you need him? :cool: :grin:
 
S

stew

Senior Member
Location
federal way,washington
Tom you say 20 amp dedicated only. I say again what about 430.24 several motors or a motor(s) and "other loads". and 430.53 several motors or "loads" one one branch circuit. In my opinion this part of the motor section specifically allows "other loads" and does not specify what these loads are to be. I do not see where a dedicated circuit is required.
 
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frenchelectrican

Senior Member
Location
Nord'est Wisconsin et Paris France
jim dungar said:
Square D QO and HOM breakers in the 15A and 20A single pole versions have a "Qwik-Open" mechanism that effectively cause them to trip at about 6X FLA (maybe even less), therefore a motor load approaching the rating of the breaker may trip on start-up.

Square D makes a slow trip version of the QO. Their HID breakers also do not have the quick trip characteristic.

Myth buster fact: HACR ratings do not guarantee that a breaker can handle motor startup currents
Click to expand...

Yep Jim and i just checked the SqD catalog and yes they have listing on HM [ high magatic verison ] on both QO and HOM lines

Merci, Marc
 
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Lxnxjxhx

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20A Homeline Breaker tripping with compressor

this gentleman

Aric Luck
Square D/Schneider Electric
Customer Information Center
Circuit Breakers Product Support Group
Phone (888) SQUARED (778-2733)
Fax (859)817-6771
For Circuit Breaker Technical and Application Assistance, email:
cedarrapids.psg@us.schneider-electric.com

can send you two graphs, 730-5.pdf and 730-4.pdf, on "trip curves".
 
L

Lxnxjxhx

Guest
20A Homeline Breaker tripping with compressor

I'd still put a peak-hold ammeter on the line with the breaker installed to see how close you are to tripping.
 
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