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Posted By: harold endean Re: Fan motors - 09/29/12 05:35 PM
I might have posted this one before, you know getting old and forgetful. Anyway, in house with bathroom fans where the fan motor is in the attic, and the motor can be activated from several different bathrooms. The bath fan motor is a fractional HP, is a disconnect switch (snap switch) needed by the fan? Can you install a breaker lock in the panel for that circuit? (Even though there would be other outlets on that circuit including an attic light.)
Any thoughts?
Posted By: gfretwell Re: Fan motors - 09/29/12 06:00 PM
Code wise a properly labeled breaker with a lock should be compliant but since the light is also on this circuit, a local switch certainly makes more sense. I am not sure it would even cost more.
Posted By: Scott35 Re: Fan motors - 09/29/12 07:55 PM
I am almost 100% sure that the Branch Circuit Overcurrent Device may also serve as the Disconnecting Means (Motor of 1/8 HP max. in a fixed location...)
Heck, if the Blower Assembly is Cord and Plug connected, the Disconnecting Means could be done by Unplugging the Cord from the Receptacle.

The above Should meet minimal compliance, per 2008 NEC - or more accurately in Californ-ieee-yaaa, the 2010 CEC (Title 24, Part 3: Californ-iee-yaa Electrical Code).

IIRC, Motors of 2.0 HP and less would require some type of Local Disconnecting means - i.e.: General Use Toggle Switch, Motor Rated Switch ("Manual Starters"), EXO type Safety Switch, etc.

Personal input:
All the Roof Mounted Exhaust Fans I have seen/installed/fixed/serviced, or inserted as a Block on Electrical Plans [denoted and specified after inserting the appropriate Block, which looks like " \O\ " ... helps if you are drunk ;)]
have / had a Snap Switch mounted external to the Assembly, either directly to it, or within 5 Feet of the Assembly.

Not that this is the only way to achieve Compliance to whatever Code(s) will be applicable to the Equipment, only this is the most prevailing Disconnecting Means method I am used to.

-- Scott (EE)
Posted By: harold endean Re: Fan motors - 09/30/12 05:45 PM
Greg,


Would sec. 430.109 (B) mean that the circuit breaker can be used as the disconnect means? If so, would you need a breaker lock on it?
Posted By: harold endean Re: Fan motors - 09/30/12 06:12 PM
Scott,

As we all know the code is a minimum and we all know what good mechanics should do. However if you get someone, who just wants to do the minimum, because of low bid, then I will have to quote him chapter and verse where it is enforced in the code book.
Now if he has a breaker lock on the circuit, it can be the required disconnect as per 430.109 (B).

Also by the same scenario if the attic light is on the same circuit as the bath fan and the EC locks it out to work on the fan motor, he now can't see the motor.

So if I look at a job and there is no circuit breaker lock and no snap switch for the motor should the job fail?

Maybe under sec. 430.102(B)(1)?
Posted By: gfretwell Re: Fan motors - 09/30/12 06:40 PM
Short answer, yes.

I really prefer the local disconnect switch but the code still allows a breaker lock.
I wonder how many of these breaker lock devices ever get used.
I was hard enough to enforce LOTO procedures in managed commercial installations. I bet residential use is in fractions of one percent. Do residential electricians even have LOTO equipment on their trucks? Certainly the homeowner or the handyman doesn't. I do have a LOTO tag in all of my breaker boxes on a short piece of #12 that goes in the hole of a breaker handle, just for my protection.

Ever forget? Happened to me. wink
Posted By: harold endean Re: Fan motors - 10/01/12 12:01 AM
Greg,

I know what you mean about LOTO and when I was in business and I had 4 trucks all of my trucks had a LOTO kits. Did they use it? Who knows for sure. PLUS, I also had 3 licensed electrical contractors working for me. I am pretty sure that most of those LOTO just gathered dust.

This still leaves me with a question, should a bathroom fan that has several switches in different rooms need a snap switch to act as a disconnect for the 1 motor that is in the attic?
Posted By: HotLine1 Re: Fan motors - 10/01/12 12:37 AM
Harold:
Sounds like you're going to have to make a call on that. IF the cb gets LOTO, the attic light & whatever else may be on that circuit is DOA.

A snap switch; cord & plug, or a real disco within sight? As it cannot be locked 'off' without creating a possible life safety issue due to no light in the area of the motor, and (I'll stretch here) there are 'multiple switches' that may energize the circuit, then it needs a means of disconnect within site.

Although the letter of the Code allows a CB lockout, doing that in your case creates a life safety issue. One question please, is there a receptacle in the attic?? Is it on the same circuit??
Posted By: gfretwell Re: Fan motors - 10/01/12 06:10 PM
I bet, setting a box with a snap switch is cheaper than any of the other solutions. Those breaker lock out kits are not cheap.
Posted By: sparkyinak Re: Fan motors - 10/02/12 12:19 AM
Here's a thought. Aren't motors suppose to have a service disconnect switch within line of site if the motor it serves?...
Posted By: gfretwell Re: Fan motors - 10/02/12 02:16 AM
Harold pointed out the article that allows the breaker to serve as the disconnect on small motors.
John pointed out why that may not be a good design or even a safe way to go.

This is one of those things where I would try to just cajole the installer to do the right thing without starting a wizzing contest.
Posted By: HotLine1 Re: Fan motors - 10/02/12 02:24 AM
IMHO, a chat with the electrician should solve this issue without any wizzing by all parties.

A small cost to install a box, switch & plate, and a few staples, & perhaps two NM connectors will save a lot of greif.

Posted By: sparkyinak Re: Fan motors - 10/02/12 04:19 AM
....and wizzing around wires and fan motors usually don't end well...
Posted By: Scott35 Re: Fan motors - 10/03/12 06:16 AM
Is this Motor's Power Rating greater than 1/8 HP, but less than 2.0 HP?

Additionally, is the Blower Motor energized by more than One Source?

Section 430.109(B) allows for the use of the Branch Circuit Overcurrent Device to also serve as the Disconnecting means for Stationary Motors of 1/8 Horsepower (HP) or less.

Section 430.109(C) allows Disconnecting means for Stationary AC Motors - size above 1/8 HP, to 2.0 HP (connected to systems of 300V or less), to be either properly rated Snap Switches or Manual Motor Controllers.

Many small Fractional Horsepower AC Motors will be rated in Wattage, Equivalent to what is found at the Output (Motor Shaft).
If a Motor has a listed True Power Rating of 93 Watts, that would be 1/8 HP.

Any Wattage rating GREATER-THAN 93 Watts indicates a Motor with an output greater than 1/8 HP.

Consequently, any Wattage rating LESS-THAN OR EQUAL TO 93 Watts indicates a Motor with an output of 1/8 HP, or less.

Another Section in Article 430 may apply to Compliance is Section 430.102(B), Exception(a)... Where such location of disconnect means introduces increased hazards to personnel.
This would be applicable if the Blower Motor is on the same circuit as the Attic Lighting / General Equipment Service Receptacles.

As mentioned by others, it is a minimal cost involved to include a Snap Switch at the Blower, to serve as a Disconnecting means.
It is almost a "No-Brainer" (Default Installation Concept) for an Installation such as the one described in this Thread
(Exhaust Fan's Blower Motor is controlled from 2 or more Bathrooms).

Since the Exhaust Fan serves more than One Bathroom, the Blower _SHOULD_ be larger than 1/8 HP, in order to actually move enough Air to be considered an Exhaust Fan!
Regardless of which Bathroom Switch energizes the Motor, the Blower will still have to move the Air from all Bathrooms connected to the Exhaust Fan Assembly - via the connected Ducts.

Note: The above takes in to consideration that the Air Moving System is properly designed... whistle

If the System has "Selective" possibilities - where the Ducts going to the Bathrooms have dampers, which are opened only when the Switch at that Bathroom is Closed, the Motor would be Speed Controlled according to the number of open dampers, yet will be of a full load size in the 1/4 to 1/3 HP range (if not larger).

These final comments are to indicate a Blower which exceeds 1/8 HP, and therefore does not qualify for the Disconnecting means permitted by 430.109(B).

Good luck!!

-- Scott (EE)
Posted By: harold endean Re: Fan motors - 10/05/12 02:01 PM
You guys are all right, and I went out yesterday and the EC did the right thing with a disconnect (snap switch) by each and every fan. This house had over 7 bathrooms and sauna and gym, etc. so there must have been at least 7-9 fans in this house. Some fans were operated from 2 bathrooms. Hence the need for a disconnect at the fan and not to rely upon the breaker lock. NOW comes a small twist to this story. There was a sub panel in the attic where several of the fans were located. The panel was in sight of every fan. He then could have used the breaker as a means of disconnect as long as the attic lights weren't on that circuit.
Posted By: gfretwell Re: Fan motors - 10/05/12 05:42 PM
Quote
The panel was in sight of every fan. He then could have used the breaker as a means of disconnect as long as the attic lights weren't on that circuit.


I think so if that is all true.

You must have a different kind of attic there if you can get all of the "space" requirements in front of a panelboard. wink

Pull down steps are fairly rare here and attics are "crawl on your belly" or at least "duck walk" affairs.
Posted By: HotLine1 Re: Fan motors - 10/05/12 06:57 PM
Greg:
Some of the 'attics' in my town could (and sometimes are) be used as habitable living space.

Think of a three story SFD kind of appearance.

Vertical furnaces are not uncommon. Great location for the second floor 'smart house', alarm, etc. panels also.

Posted By: gfretwell Re: Fan motors - 10/05/12 07:09 PM
OK it makes sense now. With all of our 3:12 and 4:12 roofs, attics are far from inhabitable.
This is our typical attic framing. With all of the cross bracing it was hard to get 8' of clear space on the floor.

http://gfretwell.com/electrical/addition/smurf%20job.jpg
Posted By: HotLine1 Re: Fan motors - 10/06/12 01:08 AM
The next McMansion I get to, I'll get a shot of the 'attic' stairs, and the 'attic'.
Posted By: harold endean Re: Fan motors - 10/07/12 09:57 PM
John, and Greg,

Oh Yeah, this attic is large. It has 4 HVAC air handlers systems up there. You walk up into the attic. You also have stairs up and over two or three duct lines. I have to go back for a final inspection, when I do, I will also try to get some pictures for you guys.

Posted By: Scott35 Re: Fan motors - 10/08/12 10:53 AM
Quote


He then could have used the breaker as a means of disconnect as long as the attic lights weren't on that circuit.



That would be Compliant only for a Single Stationary Motor of 1/8 HP or less.
Reference: 2008 NEC Section 430.109(B)

If the Motor is rated > 1/8 HP, to 2.0 HP; - 300V or less, then a Local In-sight Disconnecting Means is required.
Reference: 2008 NEC Section 430.109(C)

-- Scott (EE)
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