What size wiring for Central A/C compressor?

[The Daring Dufas]

I'm sure someone manufactures a molded case high current switch like that but I haven seen one and I don't know of one that would have built in over-current protection. ^_^

TDD

[trader4]

It would have to be not only a unique breaker, but also a unique panel to accept said breaker. It doesn't exist for some very good reasons. And if it did, what do you think that special panel and those special breakers would cost compared to the simple alternatives?

[HeyBub]

Just an observation, but none of the devices offered on this website are UL approved. They claim to meet "all NEC requirements for optional standby systems (Article 702)," but that's easy to say.

[trader4]

They go a bit further than that. They have the test reports that show that they have been tested for use as accessories with UL 67 listed panelboards. What exactly that means in regard to making them code compliant when put on a panel, I don't know. This issue is why I recommended going with an interlock from the actual panel manufacturer, if one is available. That way you know there is no issue. From some discussions I've seen online it looks like people are using the Interlockit product. How many of those are actually inspected, do some inspectors have issues with it, IDK. Given that it's just a piece of metal, has no direct involvement with the electricity, obviously does what it' intended to do, I'd have no problem using it from a safety standpoint. But it would be a bitch to buy it, install it and have it rejected. I guess best thing would be to take a print out of the info, including their test report, over to the inspector and ask before buying. Especially if you're in an area that tends to be tougher.

[bud--]

They usually show up when threads get into connecting generators to the house panel. Last time was probably November.

You can add a subpanel and move some of the loads to it.

Panels will have a limitation on where you can install half-sized breakers. It may be in all positions, no positions, or anywhere in between. The label will tell you. Half-size/twin breakers (in general) can only be installed where the label says they can.

"Tested for use with UL 67 Listed Panelboards Ref. Wyle Laboratories Test Report T52431-01 Wyle is a Nationally Recognized Testing Laboratory authorized by OSHA for UL standard 67 and recognized by all 50 US States"

Depends on whether your AHJ recognizes Wylie. There is probably not a clean way to get these interlocks listed for other manufacturer's panelboards. But they are a mechanical device that does not have electrical ratings - likely they are OK. Ask the AHJ.

Several manufacturers (including SquareD and Siemens) have a similar mechanical interlock for their panels.

[gfretwell]

I have mixed emotions on the interlock deal. I have seen some shop built ones that are better than the Square D model but it is still not listed. Legally I would have to reject it or "own" it (article 90-4). I might tend to owning it personally but that decision is reall;y up to my boss if I worked for a municipality,.

[bud--]

"Tested for use with UL 67 Listed Panelboards Ref. Wyle Laboratories Test Report T52431-01 Wyle is a Nationally Recognized Testing Laboratory authorized by OSHA for UL standard 67 and recognized by all 50 US States."

report from Wyle Laboratories

"Representative samples of the product covered by this report have been evaluated and found to be suitable for use with UL 67 listed panelboards provided the Conditions of Acceptability are met." The "Conditions of Acceptability" are included - generally installation by someone who is not an idiot.

I wouldn't bet UL standards envision testing devices made for other electrical manufacturers products (other than "classified" breakers).

Would Wyle give you enough cover? Any opinion of whether other inspectors are likely to accept it?

More generally, what is the acceptance of NRTLs (other than UL and the former FM) for electrical approval? (The OSHA process is OSHA has a list of standards - mostly UL for electrical. And it has a list of NRTLs. NRTLs are individually qualified for each standard they are allowed to approve for, for OSHA. I kinda remember Los Angeles does the same thing.)

[gfretwell]

uh ... not so much

Organizations Currently Recognized by OSHA as NRTLs

Canadian Standards Association (CSA) (also known as CSA International) Communication Certification Laboratory, Inc. (CCL) (DBA Nemko-CCL, Inc.) Curtis-Straus LLC (CSL) FM Approvals LLC (FM) (formerly Factory Mutual Research Corporation) Intertek Testing Services NA, Inc. (ITSNA) (formerly ETL Testing Laboratories, Inc.) MET Laboratories, Inc. (MET) NSF International (NSF) QPS Evaluation Services Inc. (QPS) SGS U.S. Testing Company, Inc. (SGSUS) (formerly U.S. Testing Company, Inc./California Division) Southwest Research Institute (SWRI) TUV Rheinland PTL, LLC (TUVPTL) TÜV SÜD America, Inc. (TUVAM) TÜV SÜD Product Services GmbH (TUVPSG) TUV Rheinland of North America, Inc. (TUV) Underwriters Laboratories Inc. (UL)

[bud--]

The report from Wyle is dated November 2009. According to OSHA, Wyle was a NRTL until August 2011 and one of the standards they could test for was UL 67.

So is the report still valid?

If it was valid when issued in 2009 does that give you a cover?

[Steve Barker]

a new unit will require less amps.

10 ga on a 30 is all you need for what he has.

[adamsjoey94]

well you will just have to upgrade

[adamsjoey94]

[adamsjoey94]

[adamsjoey94]

[adamsjoey94]

[gfretwell]

Wrong, 10ga is plenty. There are different rules for motor loads

[trader_4]

IDK why this old thread had to be re-opened, the full thread with all the facts is here, but as you say, what's there is fine. The problem is that some people can't understand that motor load circuit breakers are sized differently and you can have a breaker that is larger than would be allowed for a lighting or water heater circuit that used the same size conductor.

[djhumvee]

lol so they come and arrest you for arguing with them? Where do you live? Afghanistan? China?