Are butt splices allowed in explosion proof motor disconnects? If anyone knows and can direct me to the applicable NEC code I would very much appreciate it. This is what I found while troubleshooting a motor stop circuit in a new installation in two of the disconnects.
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Butt splices in explosion proof disconnect
- Thread starter wdd0422
- Start date
Explosionproof enclosures are used more often as a method of protection in North America.
NEC [NFPA 70] art.500 rules the Hazardous Location protection.
The Hazardous Locations are classified into 3 classes each one in 2 divisions.
If the disconnector is mounted in a Hazardous Location approved enclosure a splice is permitted in this enclosure for class I div.1 for instance. The conduit entering the enclosure has to be sealed according to art.501-5.
NEC [NFPA 70] art.500 rules the Hazardous Location protection.
The Hazardous Locations are classified into 3 classes each one in 2 divisions.
If the disconnector is mounted in a Hazardous Location approved enclosure a splice is permitted in this enclosure for class I div.1 for instance. The conduit entering the enclosure has to be sealed according to art.501-5.
not sure what rule to point you to but I bet you can read the book yourself.
Butt splices aren't a bad thing. It just depends on your preference. Do you want pretty or practical?
And what size of wire are we talking about? Power conductors or controls?
As far as I know a butt splice is an approved connection as long as it is done properly in an approved enclosure. You have a problem with that? Is that not what you have? Are your butt splices done properly? If so then why the concern.
Explosion proof doesn't mean NASA rocket ship wiring or Swiss engineered control relays. It means you "seal" the enclosure so that nasty sparks and the like don't escape from said enclosure in the event of wiring problems.
You are missing the point about the big things by paying too much attention to the little things.
What's the real issue here? You dislike your coworker's work? You dissing other contractors? Who made you quality control?
Butt splices aren't a bad thing. It just depends on your preference. Do you want pretty or practical?
And what size of wire are we talking about? Power conductors or controls?
As far as I know a butt splice is an approved connection as long as it is done properly in an approved enclosure. You have a problem with that? Is that not what you have? Are your butt splices done properly? If so then why the concern.
Explosion proof doesn't mean NASA rocket ship wiring or Swiss engineered control relays. It means you "seal" the enclosure so that nasty sparks and the like don't escape from said enclosure in the event of wiring problems.
You are missing the point about the big things by paying too much attention to the little things.
What's the real issue here? You dislike your coworker's work? You dissing other contractors? Who made you quality control?
- Thread starter
- #4
No, I'm not trying to "dis" anyone. As I mentioned in the original post, the problem was in the stop circuit, so it was the control wiring (#12). There was water in the disconnect, this caused the wires to short at the splice and burn completely through causing the circuit to be open. This was in more than one location. I understand the primary issue is the water and I know this is unacceptable but I was wondering about butt splices. Yes I do have some concerns about the contractor. Overall they did a good job but I also have some instrumentation that has water in it. This is a new installation and it should be done correctly. I'm not quality control but I am going to have to maintain it. I don't understand your hostility but thanks for the info anyway.
The code does not contain provision for a good practice but "only practical safeguarding of person and property from hazards arising from the use of electricity" as underlined on Introduction.
Art. 300-13 a-no splice is permitted in a raceway itself so it is obviously understood the splice may be a fire source.
If the cable length is more than delivery length no other possibility is but to splice the two lengths.
But, in spite of skiir explanation that but splice could be done professionally the splice is a wick chain in a conductor.
It is not a good installation policy to splice the conductor from the beginning but only as urgency mean.
So you are right wddo422, if no splice is required is not a good practice to splice it close to the disconnector.
Art. 300-13 a-no splice is permitted in a raceway itself so it is obviously understood the splice may be a fire source.
If the cable length is more than delivery length no other possibility is but to splice the two lengths.
But, in spite of skiir explanation that but splice could be done professionally the splice is a wick chain in a conductor.
It is not a good installation policy to splice the conductor from the beginning but only as urgency mean.
So you are right wddo422, if no splice is required is not a good practice to splice it close to the disconnector.
resqcapt19
Electrical
The water problem with explosionproof enclosures is something that is often missed. A NEMA 7 (explosionproof enclosure) is not suitable for use in wet locations unless it also has a NEMA wet location rating like 4 or 4X. Many enclosures have both ratings, but a number have only the NEMA 7 rating.
Providing a breather and a drain is a good idea indeed. See- for instance:
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