I'm looking at the 3hp SS3L3 AND NEED TO KNOW WHAT SIZE BREAKER YOU HAVE IT CONNECTED TO. THE SPECIFICATION SAY 14.7 AMPS. i HAVE A 30 AMP BREAKER AND #10 GUAGE WIRE ALREADY ON THE CIRCUIT. WHAT IS YOURS CONNECTED TO. I HAVE NEVER USED ANYTHING BIGGER THAN 30 AMPS BEFORE. CAN YOU TELL WHAT YOU HAVE ON YOURS?
ingersolrand air compressor
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grsthegreat
Super Star Member
30 amps will be more than enough. A 3 horse power i assume 220 volt (as most compressors are) would probibly run ok on a 20 amp , 240 circuit (assuming the unit is fairly new and the brushes arnt worn too badly), but you can protect any motor up to 125% over the full load amps to allow for motor starting loads. I install all larger compressors on 30 amp circuits with #10 wires.
BTW: In my own recent shopping for this level of compressor ($599 at TSC, $499 at Lowes, etc), they all mention that "it runs very hot". The compressed air is very hot and will discolor the paint on the tank. One evaluator stated that he change the air delivery pipe (pump to tank) from 1/4" to 1/2" and this helped lower the air temperature.
What's your experience with this compressor? I need to upgrade to run an enclosed sand blaster (12 cfm recommended).
What's your experience with this compressor? I need to upgrade to run an enclosed sand blaster (12 cfm recommended).
grsthegreat
Super Star Member
\The smaller single stage compressors do run hot. I paid about 800 for my compressor about 6 years ago. 60 gal unit. It puts out 14.5 cfm so runs everything i need, but is soooooo daarn noisy.
When this ine bites the dust, im getting a nice 2 stage compressor..maybe an 80 gal tank unit.
kelloggguy
New member
You should have a 30 amp circuit for the 3 HP, 15 amp compressor. The initial inrush current on that motor can push 30 amps for a short time.
kelloggguy
New member
"It runs very hot" actually means "it's not going to last very long," because they are running it at the maximum speed possible, and it is being pushed to the limit. If you want a compressor to last, get one that runs slower, typically 600-900 RPM, rather than the 1200-1500 a lot of the cheap, single stage, big box store units run. Slow speed equals long life!!!
A 3 HP unit will give you about 10 cfm at 100 PSI. If you need at least 12 cfm, you should buy at least a 4 HP or a
5, to get the flow you need. The 3HP will not do it.
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grsthegreat
Super Star Member
cant agree more. I only bought my cheap box store single stage unit to last a year or so till i could afford a better, costlier one. That was 6 years ago. It still runs hot, but it still runs strong.
Mine is an Ingersoll Rand 3 hp compressor 240v single phase motor. Connected to a double 20A breaker, ran #12 THHN wire in conduit. Your compressor FLA is below the 80% limit of 16 amps. Mine has never tripped out on inrush. The motor is capacitor start, no brushes.