La Marzocco GS3 Amperage Requirements

Need help with equipment usage or want to share your latest discovery?

#1: Post by btalcox0715 »

Just pulled the trigger on a LM GS3 MP :D In my 3-4 week wait, I have been and will be researching as much as I can about the machine prior to receiving it. I thought to myself, "I bet this machine pulls a bit more power than my R58.." and thats when I learned about the full power and half power modes.

I currently live in an apartment and the GS3 will (obviously) be going in my kitchen. I've got the NEMA 5-15 GFCI outlet(s) in the kitchen on a 20A circuit. Probably more of an electrician question, but the GS3 has a NEMA 5-15P plug, so (theoretically) it shouldn't pull more than 15A. NEMA 5-15 and NEMA 5-20 outlets _should_ be the same internally, so there should be no problem running full power mode through a NEMA 5-15 on an up-to-code 20A circuit?

Thanks in advance!

Team HB

#2: Post by JRising »

If it has a NEMA 5-15 receptacle, then it is at best an "up to code 15 amp circuit". But, as you seem to already know, it's possible that it it's wired with 12 gauge and is the only receptacle on its 20A breaker so could conceivably be turned into a 20 A circuit.

And yes, as people have proven, a good NEMA 5-15 receptacle will be okay at 20 amps for a very long time.
You can probably read the gauge of the machine's own power cable to ensure it's 12AWG.

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Team HB

#3: Post by cannonfodder »

Depends. Power requirements are 15A (20A full power). Aside from the physical plug, the question is what else is on the circuit. You need to check that to make sure you are not overdrawing on the total load.
Dave Stephens


#4: Post by spearfish25 »

How's the new GS3 working out? What did you find out with the full power mode and your setup? Looking to do the same upgrade.
Alex makes me want to buy expensive stuff.

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#5: Post by stefano65 »

12 awg is good 10awg better
80% is what code requires for load to draw
Just consider what else is plugged in on the same circuit
Stefano Cremonesi
Stefano's Espresso Care
Repairs & sales from Oregon.


#6: Post by Sp0ke »

That's the thread I was looking for!!!

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#7: Post by Milligan »

FWIW, most kitchen circuits are 20amp which is 12 gauge. You can check at the electrical panel by looking at the breaker BUT if you feel comfortable doing it then taking the panel cover off and confirming that the wire is indeed 12ga is best. I worked in home renovation previously and the amount of bad work is sadly quite high.

It is BEST to have that unit on a dedicated circuit with 12gauge wire, 20 amp breaker, and a 20amp rated receptacle. Especially on initial warm up. For example, if you had the GS3 warming up on one socket then tried to make toast, start an electric kettle, or some other common kitchen task the you could trip the breaker.

I had my GS3 in full power mode on a 20 amp circuit that was shared with one other outlet that I used my grinder and electric kettle on. I was mindful of when I used my grinder and the kettle. I never tripped a breaker.

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BaristaBoy E61

#8: Post by BaristaBoy E61 »

Properly wired dedicated 20 circuit with GFCI outlet.
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

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#9: Post by bostonbuzz »

My gs3 cord itself gets pretty warm during the initial warm up at full power. That and my lights dimming made me a little nervous, so I use it in half power mode.
LMWDP #353


#10: Post by Mike-R »

bostonbuzz wrote:My gs3 cord itself gets pretty warm during the initial warm up at full power.
Just curious, what is the marking on the cord (i.e, AWG or mm2)? I wonder if it's really meant for 20A use. Where I'm going with this is perhaps La Marzocco provides a 15A cord for half power mode and expects it would be replaced with a more robust 20A cord before using it in full power mode.

I had a Mini Vivaldi II a few years back and it came with a (very thick) 20A cord with a NEMA 5-20 plug. It also included an adapter to plug it into a NEMA 5-15 outlet in case it would be used in 15A mode.