preferred orientation of disconnect handle 5

[PaulKraemer]

Hi,

I am going to be using a control panel door mounted disconnect for which the handle looks like this ...

... This handle is constructed so that it will rotate 90 degrees clock-wise from the OFF position to the ON position. It seems this will allow me to mount this in a few different orientations. I am trying to decide which of the following would be a better choice:

(1) ON with the handle pointing to the left, OFF with the handle pointing down.
(2) OFF with the handle pointing to the right, ON with the handle pointing down

If anyone can tell me if either of these orientations is generally preferred, I would greatly appreciate it.

Thanks in advance,
Paul

 

[Crowbar1]

The instructions included with the disconnect handle will indicate proper mounting.

Rich

PRA

 

[waross]

Canadian Electrical Code.

(2) Single-throw knife switches shall be mounted so that gravity will not tend to close them.

While this may not be applicable, It is common practice to follow this convention whenever possible.
This tends to avoid confusion.
Down is off or off is down.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[IRstuff]

In addition to the above, ergonomics should also be considered; in most places pushing/pulling down turns off things. My thinking is that the OFF position of the switch should be at the 6 o'clock position

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[che12345]

Mr. PaulKraemer (Electrical)(OP)4 Aug 23 16:50
" ... This handle is constructed so that it will rotate 90 degrees clock-wise from the OFF position to the ON position. It seems this will allow me to mount this in a few different orientations. I am trying to decide which of the following would be a better choice:
(1) ON with the handle pointing to the left, OFF with the handle pointing down.
(2) OFF with the handle pointing to the right, ON with the handle pointing down. "
I submit my personal opinion for your consideration. It dependents on:
1. Local regulations/rules by testing/approving body, if any,
2. Standards e.g. NEC in the US. See Article 380-7 which states " where these switches handles are operated vertically rather rotationally or horizontally, the up position of the handle shall be the on position".
Note: As the switch is rotationally, therefore, this rule is irrelevant.
3. Standard practice adopted in the plant, where the operators are trained/familiar of,
4. Ergonomic to be taken into consideration, especially with higher current ratings where considerable force is required to rotate the handle.
With ergonomics taken into consideration, I am of the opinion that (2) is preferred.
Che Kuan Yau (Singapore)

 

[waross]

Over 50 years ago, I worked in a plant with rotary handles on the MCCs.
I can't remember a North American manufactured switch or MCC that used down for off.
Memory may be failing, but your #3 will cover the majority of North American industrial switches.

3. Standard practice adopted in the plant, where the operators are trained/familiar of,

Where there is a choice, down is off.
And ergonomics? Off should be easier than on when there is any difference between the two as far as operating force.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[che12345]

Mr. PaulKraemer (Electrical)(OP)4 Aug 23 16:50
" ... This handle is constructed so that it will rotate 90 degrees clock-wise from the OFF position to the ON position. It seems this will allow me to mount this in a few different orientations....."
In addition to my earlier post, I wish to point out some precautions during installation, which I consider them essential. Careless mistakes do happen !
1. Usually besides the handle that can be rotated, the base mounted disconnect switch can also be rotated. Attention: Check and reconfirm that the switch is in the open condition when the handle is in the O = off position.
2. Most design has a interlocking catch which ensures that the panel door cannot be open when the handle is in the I = on position; unless bypassed the mechanism manually.
3. Most design also has the provision for pad locking the switch in the O = off position. Attention: It is prohibited to lock the switch in the I = on position !
Che Kuan Yau (Singapore)

 

[PaulKraemer]

Hi Che, Waross, IRStuff, and Rich,

Thank you for your replies. It makes sense to me that it should be easier to turn the switch OFF than it is to turn it ON, and if gravity were to have an effect, gravity should turn it OFF rather than ON. This makes me think that mounting the switch so that down (6:00) is OFF makes the most sense. To Crowbar's point that the Manufacturer's instructions should explain the proper orientation, I have found these to be unclear. My disconnect is a Schneider Electric GS2GU3N. The accessories I have are a GS2AH140 rotary handle, a GS2AE2 shaft extension, and a GS2AEH12 guiding support. The rotary handle shipped with an adhesive backed label to assist with drilling the necessary holes in the panel door, which looks like this...

... The label makes me think that OFF should be in the 6:00 position, but page 2 of the following instruction bulletin seems to contradict this...

https://www.se.com/us/en/download/document/30072-454-21/

I emailed Schneider technical support to ask for some clarification. I will post here if / when I receive a reply. If the additional information I have provided makes anyone here think that OFF at 6:00 is a better choice than OFF at 3:00, or vice versa, I'd greatly appreciate anyone's opinion.

I looked at some old photos of a panel in which I used this same disconnect previously. For that panel, I picked out the disconnect, but I had a UL panel shop assemble and wire the panel. They mounted the disconnect so that down (6:00) was OFF and and left (9:00) was ON. They didn't ask me my preference and I never thought about it. It worked and I never had any complaints from my customer or from any inspectors. This time, I have to mount it myself, so I'm just hoping that I can explain my reasoning for whichever way I end up mounting it.

I appreciate all your help.

Best regards,
Paul

 

[IRstuff]

Have to be able to easily see both the "ON" and "OFF" markings on the switch, so that limits the possible positions. The "OFF" marking at the top makes more sense to me.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[PaulKraemer]

Hi Rich, Waross, IRStuff, and Che,

Thank you all for you input. It is very much appreciated. The case that handle pointing down (6:00) would be OFF and handle pointing left (9:00) would be ON seems logical to me. A switch like this wouldn't be affected by gravity, but if it were, gravity would pull the handle down. Also, if someone tripped and grabbed the handle to avoid falling, this would result in the handle being pulled down. In these situations, it seems like it would be safer in these events if power were turned OFF rather than ON.

With this being said, Schneider technical support got back to me and said that the correct orientation is for handle pointing right (3:00) to be OFF, and handle pointing down (6:00) to be ON. They offered no explanation regarding the reasoning for this, but I mounted it according to their recommendation and it works. I'm sure it would have worked just as well in the other orientation, but I figure it is best to follow manufacturer recommendations.

I appreciate all of your time and help.

Best regards,
Paul

 

[LionelHutz]

We always mount that type of rotary handle with Off down. On at 9:00 is still up compared to off at 6:00. On pointing down is rather dumb.