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As the title suggests, is a disconnect switch located near the outdoor unit of a mini-split legally mandated or a convenience item? In my case, the breaker panel is about 20' from the outdoor unit, and the mini split is on a dedicated (and labeled) circuit.

Since local codes may vary, I am in the US. I don't believe my city has any regulation requiring a switch, but I am less sure about the national level.

  • What's the nameplate rating on this mini-split? You might be able to use an ordinary wall switch in a suitable box/cover combo for the disconnect... – ThreePhaseEel Apr 5 '17 at 22:19
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    Actually, I know I can. It lists an MCA of 10A and an MOP of 15A, so I was planning to use a weatherproof switch cover on the junction box serving the mini split ODU, if needed. – Hari Ganti Apr 5 '17 at 23:23
  • I thought all but the smallest of these mini-splits required 230 V. In the US this means a double pole switch. – Jim Stewart Apr 6 '17 at 3:00
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    @JimStewart Just trying to use existing equipment. They don't cost much, I am aware. Anyway, as I said earlier, 10A @ 240V, 9kBTU/hr nominal cooling, 10.8kBTU/hr nominal heating. In case you're curious: acwholesalers.com/hvac/pdf/lg/lg-ductless/LS090HSV4-sb.pdf – Hari Ganti Apr 6 '17 at 18:07
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    Amazing, 2 kW moves 10 kBTU/h which cools or heats a good sized room. The SEER 21 does the trick. – Jim Stewart Apr 7 '17 at 1:01
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It is legally mandated, and part of the National Electrical Code (NFPA70). NEC is adopted across most of the US.

National Electrical Code 2014

Chapter 4 Equipment for General Use

Article 440 Air-conditioning and Refrigerating Equipment

440.14 Location. Disconnecting means shall be located within sight from and readily accessible from the air-conditioning or refrigerating equipment. The disconnecting means shall be permitted to be installed on or within the air-conditioning or refrigerating equipment.

The disconnecting means shall not be located on panels that are designed to allow access to the air-conditioning or refrigeration equipment or to obscure the equipment nameplate(s).

It's largely a safety precaution to ensure the power is off if someone is servicing the unit.

If your breaker panel is 20' away and within sight of the unit, it's probably acceptable as a disconnect means but of course your AHJ (inspector) will have to agree. If you can't see it, you'll have to put in a separate disconnecting means.

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  • It's around the corner meaning within 20', but on a different wall of the house. At any rate, per @ThreePhaseEel, I plan to use a simple wall switch in a weatherproof cover on the junction box serving the unit. – Hari Ganti Apr 5 '17 at 23:25
  • It depends on where you live and if the breaker has lock out lugs. Also the required service outlet. If within site 50' per NEC definitions "in site from" and can be locked out this fulfills the requirement but it requires lugs. I believe because even with the door locked the cover can be removed on many panels. – Ed Beal Apr 5 '17 at 23:32
  • Yeah, I don't have lock-out lugs, but the box locks without the ability to remove the panel. – Hari Ganti Apr 6 '17 at 5:02
  • @hariGante Assuming your unit is 240V, a simple wall switch won't do. The feed actually consists of two hot wires and both must be switched. A "spa disconnect" will do what you need. – DoxyLover Apr 6 '17 at 16:47
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    There are double pole toggles. Available locally – NPM Aug 12 '17 at 21:03

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