Sealing cable gland needed? (Class I Div II)

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jabo44

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Location
CA
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Process Engineer
I'm dealing with a Class I Div I explosion proof solenoid valves in a Class I Div II area (have not found Class I Div II valves that work for my application), which has a potted coil and wire leads. These wire leads will be spliced to a cable inside a Class I Div II Type C condulet threaded directly to the solenoid valve, and the cable runs out to an unclassified area.

Does there need to be a cable gland with a sealing compound on the end of the condulet, or is acceptable to not have the sealing compound?
 
I mean a cable gland with a barrier, something with a putty or liquid plastic compound.
 
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TwoBlocked said:
I believe it depends on the cable. 2020 NEC, 501.15 (E) (2) & (3).
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In this case, not quite; the solenoid isn’t required to be sealed at all. In fact, it can be a general purpose enclosure in a Class I, Division 2 location which is why the OP didn’t a Division 2 enclosure in the first place.

If it did need to be sealed, only Section 501.15 (E)(3) would apply since no one makes a 501.15 (E)(2) compliant cable.
 
rbalex said:
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If it did need to be sealed, only Section 501.15 (E)(3) would apply since no one makes a 501.15 (E)(2) compliant cable.
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Thanks, I wondered about that. Had previously looked at spec sheets and never did find a compliant cable. Seems if someone did, they'd advertise it far and wide.
 
jabo44 said:
I'm dealing with a Class I Div I explosion proof solenoid valves in a Class I Div II area (have not found Class I Div II valves that work for my application), which has a potted coil and wire leads. These wire leads will be spliced to a cable inside a Class I Div II Type C condulet threaded directly to the solenoid valve, and the cable runs out to an unclassified area.

Does there need to be a cable gland with a sealing compound on the end of the condulet, or is acceptable to not have the sealing compound?
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My take is that you do not need to normally seal the end of the cable even when passing through a boundary. 501.15 (E) (3). But... if an industry normally uses such seals, even if not required, putting them in can reduce the amount of questions and arguments. damhik
 
TwoBlocked said:
This has to do with any enclosure for the sol, not with sealing the cable or conduit, which is what the OP is asking about.
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TwoBlocked said:
My take is that you do not need to normally seal the end of the cable even when passing through a boundary. 501.15 (E) (3). But... if an industry normally uses such seals, even if not required, putting them in can reduce the amount of questions and arguments. damhik
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Reread Sections 501.15 (E)(1)&(3) carefully. Since the enclosure isn’t required to be sealed, neither is the cable.
 
TwoBlocked said:
My take is that you do not need to normally seal the end of the cable even when passing through a boundary. 501.15 (E) (3). But... if an industry normally uses such seals, even if not required, putting them in can reduce the amount of questions and arguments. damhik
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rbalex said:
Reread Sections 501.15 (E)(1)&(3) carefully. Since the enclosure isn’t required to be sealed, neither is the cable.
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Thanks, I believe that is what I said, only I was speaking in general, not specifically about the OP's question.
 
rbalex said:
In this case, not quite; the solenoid isn’t required to be sealed at all. In fact, it can be a general purpose enclosure in a Class I, Division 2 location which is why the OP didn’t a Division 2 enclosure in the first place.
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Thanks Bob, it looks like under NEC 501.15(E) seals are not required if either the instrument does not allow gas into the cable or the cable itself will not transmit gas. Is it correct to assume a solenoid valve will not leak the process vapor into the cable? The process gas for my application is low pressure pure oxygen, so a leak into anything electrical could be catastrophic.
 
Technically, even if the enclosure did permit gas entry into the cable, the cable would not need to be sealed unless the enclosure did for some other reason.
Oxygen is not flammable and probably not directly connected to the coil enclosure. The “process” gas flow goes through the valve, not the coil enclosure anyway. Oxygen may enrich an ignition but is not the “fuel”.
In any case, in Class I, Division 2, if the coil enclosure doesn't need to be sealed, neither does the cable in the installation described.
 
rbalex said:
Technically, even if the enclosure did permit gas entry into the cable, the cable would not need to be sealed unless the enclosure did for some other reason.
Oxygen is not flammable and probably not directly connected to the coil enclosure. The “process” gas flow goes through the valve, not the coil enclosure anyway. Oxygen may enrich an ignition but is not the “fuel”.
In any case, in Class I, Division 2, if the coil enclosure doesn't need to be sealed, neither does the cable in the installation described.
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But if the enclosure was sealed and purged, the cable (entry point or seal-off) would also be required to be sealed, correct?

Can't stand the monkey poop.
 
Pure oxygen, Apollo 1.

A situation like that, I'd like to consult my facility's insurance company. I bet Factory Mutual has some recommendations.
 
4-20mA said:
But if the enclosure were sealed and purged, the cable (entry point or seal-off) would also be required to be sealed, correct?
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The solenoid’s enclosure was never described as being purged in the OP. The fact is, it never needed to be sealed as already noted in Section 501.120 (B)(2). A general purpose enclosure is sufficient for a solenoid in Class I, Division 2.

If someone wished to waste money by purging and sealing the solenoid, the cable itself still would not require a seal.
 
rbalex said:
If someone wished to waste money by purging and sealing the solenoid, the cable itself still would not require a seal.
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I was referencing a purged enclosure, with 120vac in it, in a classified area. Not the solenoid itself, its already epoxy poured/sealed.

In 2014 we had an Arc Flash audit that required us to purge our enclosures, with 120 in them.
 
TwoBlocked said:
Pure oxygen, Apollo 1.

A situation like that, I'd like to consult my facility's insurance company. I bet Factory Mutual has some recommendations.
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As already mentioned in post #15, oxygen may enrich an ignition but is not the “fuel” - even on Apollo 1.

Factory Mutual may have“some recommendations”, (I seriously doubt it) but at the moment, the NEC doesn't.
 
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