Aircraft Power Cord Reel

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Goldfish619

Member
Location
Tampa, FL
Occupation
Electrical Engineer
Hello,

I have a project where the end users want to change the class 1 div 1 ground receptacles (12 total) to ceiling receptacles as cord reels (12 total) in an aircraft hangar. Their reason is that their equipment isn't certified for hazardous location, and they may end up getting different pieces of equipment from around the world that may not have the proper certification.

There is an overhead crane that could potentially destroy the cord reels if they are both in-used at the same time.

So that brings me to these questions:
1. Is there a cord reel out there that is powered with push buttons (stop, down, up)? This will allow me to send signal to stop the overhead crane that is in-used if the cord reel is being powered to come down. I will have a contactor ahead of the crane circuit breaker to be "normally on" so the crane can operate when the cord reels are not in-used.
2. Do the cord reels need to be classified as class 1 div 2 if the maintenance team pull the cord below 18"? If so, wouldn't their equipment need to be rated as well?

I need to evaluate all of these points and if not feasible then my suggestion to the end user might be - get certified equipment for hazardous location.

Thank you ahead of time for all your responses and comments.
 
If it's a motorized cord reel, it stands to reason there are limit switches that prevents the cord from being "over" or "under" wound. These should be fairly easy to connect to, in order to operate a relay. Wire the relay for each reel in series; all relays have to be powered before the crane gets the "operate OK" signal. If the reels don't have accessible limit switches, rotary limits can be added.

Either way, it won't be cheap. You're looking at needing a control panel for interfacing, or having the crane manufacturer add the necessary functionality into their system.


SceneryDriver
 
There are 8 aircrafts so we need to mount them in the middle of the bay so all aircrafts can access. That’s my question exactly, where can I find in the NEC or UFC that states if the cord reel end is below 18” we are now dealing with classified space. Wondering if anyone has any experience with this before.

Thank you.
 
Goldfish619 said:
There are 8 aircrafts so we need to mount them in the middle of the bay so all aircrafts can access. That’s my question exactly, where can I find in the NEC or UFC that states if the cord reel end is below 18” we are now dealing with classified space. Wondering if anyone has any experience with this before.

Thank you.
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AHH… Now a question I can address directly. See Section 500.8, specifically Section 500.8(B)(1):

500.8 (B) Approval for Class and Properties.

(1) Equipment Identification.

Equipment shall be identified not only for the class of location but also for the explosive, combustible, or ignitible properties of the specific gas, vapor, dust, or fibers/flyings that will be present. In addition, Class I equipment shall not have any exposed surface that operates at a temperature in excess of the autoignition temperature of the specific gas or vapor. Class II equipment shall not have an external temperature higher than that specified in 500.8(D)(2). Class III equipment shall not exceed the maximum surface temperatures specified in 503.5.
Exception No. 1:
Group D equipment shall be permitted to be used for atmospheres containing butadiene if all conduit runs into explosionproof equipment are provided with explosionproof seals installed within 450 mm (18 in.) of the enclosure.
Exception No. 2:
Group C equipment shall be permitted to be used for atmospheres containing allyl glycidyl ether, n-butyl glycidyl ether, ethylene oxide, propylene oxide, and acrolein if all conduit runs into explosionproof equipment are provided with explosionproof seals installed within 450 mm (18 in.) of the enclosure.
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Read ALL of Section 500.8 though and read it carefully. And read the definition of identified in Art 100 as well. It doesn’t necessarily mean listed or labeled. If equipment is IN a classified location it must be identified for it. ”How?”, you ask - permit me to introduce Section 500.8

(500.8 (A) Suitability.
Suitability of identified equipment shall be determined by one of the following: (1)Equipment listing or labeling
(2)Evidence of equipment evaluation from a qualified testing laboratory or inspection agency concerned with product evaluation
(3) Evidence acceptable to the authority having jurisdiction such as a manufacturer's self-evaluation or an owner's engineering judgment
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