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I'm connecting a wood-working machine to a 220v outlet in my shop. The instruction manual reads:

Use the following guidelines when choosing a circuit breaker (circuit breakers rated any higher are not adequate to protect the circuit): 220v ... 10 amp, 2 pole"

The circuit I'm using has two breakers connected, each with a rating of 20 amps.

The 220v circuit I'd like to use.

I would like to avoid replacing the 20amp breakers with lower-current breakers so that the outlet can be used for other machines with higher draw.

How should I protect the machine?

Edit 1: To address the question in the comments: I'm in Canada. The company that sells/brands/distributes the tool is American -- though I'm guessing their tools are made in Taiwan.

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    Your location in the world would be helpful. I am thinking maybe UK or Europe. 10 amp breakers would be quite rare for US location. Your panel looks like North American. Are you trying to connect a European tool to North American circuit?
    – crip659
    Aug 22, 2022 at 20:06
  • Hey -- Sure thing. I'm in Canada. The company that sells/brands/distributes the tool is American -- though I'm guessing their tools are made in Taiwan. I'll edit to add the context to the initial post.
    – BenB
    Aug 22, 2022 at 20:47
  • In that case @JACK answer should work. Imagine it is almost a direct translation of instructions, instead of having a Canadian/American check it over. As far as I know, 15 amp breakers are the lowest common size here, for panels.
    – crip659
    Aug 22, 2022 at 20:53
  • @crip659, to add to this: it looks quite challenging to find 10 amp Edison-style fuses. I've seen one option by Bussman with long lead/ship times to Canada. Any recommendations on how to cope with this?
    – BenB
    Aug 22, 2022 at 21:32
  • What kind of machine is this? Can you link to it?
    – LarryBud
    Aug 23, 2022 at 16:14

3 Answers 3

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I'd be looking at getting a 30 amp fusible disconnect switch and running your feed from your wood working machine into the disconnect and then from the disconnect to the outlet. Then get some 10 amp fuses for the disconnect. You might have to get them at an electrical supply store.

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    I get the feeling OP is mixing European with North American. Am I correct in thinking 10 amp breakers are rare/not heard of, for us.
    – crip659
    Aug 22, 2022 at 20:44
  • JACK, this looks exactly what I need. Thank you. @crip659, I can't say what is unheard of. I can confirm that most of the breakers in my panel are 15, 20, or 30 amps and there are no 10-amp breakers. Hence my problem ;)
    – BenB
    Aug 22, 2022 at 20:57
  • It looks quite challenging to find 10-amp Edison-style fuses. I've seen one option by Bussman with long lead/ship times to Canada. Any recommendations on how to cope with this?
    – BenB
    Aug 22, 2022 at 21:32
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    @BenB if you feel strongly about it, I would get a disconnect enclosure designed to hold one 2-pole breaker, get a 10A breaker for it and bolt it to the side of the saw so it's part of the saw. But the 10A breaker will also be a black swan, so find the breaker first then buy the enclosure from that manufacturer. Breakers don't hop brands - they seem to fit but will burn up the bus. Aug 22, 2022 at 22:17
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    @BenB -- don't use Edison fuses! Get a safety switch that accepts cartridge fuses instead, then get 10A HRC fuses of the correct type to fit that safety switch -- these are current limiting in a way that standard North American residential breakers aren't guaranteed to be, and should be easier to find than 10A Edison base fuses anyway Aug 23, 2022 at 3:02
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Did the machine tool ship with a NEMA 6-15 type plug, or was this retrofitted (or was a wrong plug installed)?

Presumably if it was imported by a responsible Canadian company that is not nominally in the tire business, it will be CSA-listed or C/UL listed. As such, it will have an instruction book also approved by that testing lab as part of its listing. Those instructions define the scope and limits of the validity of the listing, so surely CEC has a clause saying don't exceed the instructions.

The approved instructions will tell you exactly how to hook it up (and how not to). They may have words to say about hardwired vs plug-in, and they may have words about a dedicated circuit.

Those you must follow.

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  • It comes pre-wired for 110v installation and the booklet includes instructions for rewiring it to 220v. Those instructions say "If the jointer is rewired to operate on a 220v power source, the plug must be replaced with a NEMA 6-15 plug". The reason I'm re-wiring it for 220v is because the 110v wiring requires a 20-amp breaker, and all my 110 breakers are 15a.
    – BenB
    Aug 22, 2022 at 21:36
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    @BenB then you're all set. Thanks to NEC 210.21, 6-15 sockets are allowed on 15 and 20 amp circuits (only), and so telling you to install a 6-15 plug means the unit is certified safe to be on a 15 or 20 amp circuit. Aug 22, 2022 at 21:45
  • Thanks for this. Their instructions are a bit contradictory in that way -- but this does give confidence that I can call them on it if it gives me a problem.
    – BenB
    Aug 23, 2022 at 19:02
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There are some 10A breakers available. For example, Home Depot sells this Siemens QP 10A breaker:

Siemens QP 10A breaker

but you have to make sure you have the right breaker type for your panel. I agree with other comments that this is rather unusual. The standard for most US/Canada equipment is to design to be compatible (and safe) with a 15A or 20A circuit and to specify larger sizes as needed but extremely rare to require less than 15A.

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  • I'm really wondering where you'd use a 10-amp breaker in a household AC panel. Maybe you've got to de-rate some long buried cable?
    – CCTO
    Aug 23, 2022 at 13:25
  • @CCTO Breakers primarily protect cable but they also protect equipment. For example, as part of my panel replacement/heavy-up (still in process...) the electrician checked the nameplate ratings for the air conditioner and put in a 25A double-breaker to replace the old 30A fuses. The cable is still the same 10 AWG, but that provides closer protection for the appliance. Similarly, OP's appliance says it needs 10A protection. That is rather unusual for a US/Canada appliance - most are designed for 120V 15A or 20A (or occasionally larger) or 240V 20A or larger. 240V 10A just isn't terribly Aug 23, 2022 at 14:01
  • common because you can get the same amount of power by using 120V at 20A - requiring 12 AWG instead of 14 AWG wire (+$), but only using one breaker space (-$). Aug 23, 2022 at 14:02
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    Yes, that makes sense, but that would be for hardwired equipment, probably? For plug connected equipment we're allowed to plug 16ga lamp wire into a 20A receptacle willy nilly. But yes I can certainly understand hardwired equipment specifying a breaker suitable for its internal wiring.
    – CCTO
    Aug 23, 2022 at 18:51
  • SquareD actually makes a 2 pole bolt-on QO breaker in 10A. All of my server rack PDUs use SqD QO breakers (2 and 3 pole) so I'm guessing that's the use case? Maybe they really save a ton by using 18-20 gauge branch circuit wire.
    – Chris O
    Aug 23, 2022 at 18:55

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