Hello. We have a Class I Division 2 project where we ran MC-HL cable to the devices. We have an instrument on skid that is CID1 and needs a seal. We are told that MC-HL cannot use a EYS type seal and a cable gland seal (TMCX). I cannot find any info to confirm, or dispute this. On the Eaton site for the EYS, it states " In cable systems when the cables either do not have a gas/vaportight continuous sheath or are capable of transmitting gases or vapors through the cable core when those cables leave the Class I, Division 1 or Division 2 hazardous locations." It appears they mention cable systems but not cable types. Anyone share some insight on this? Thanks.
MC-HL Seal Requirements
- Thread starter DGinWNY
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- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
TMCX connectors were invented for terminating Type MC-HL and meet the requirements for Sections 501.15(D)(1) and (E)(1).
Type MC-HL is not required to be installed in conduit; but, if it is, boundary seals are to be installed per Section 501.15(D)(2) in Division 1. For Division 2 Section 501.15(E)(3) applies.
Type MC-HL is not required to be installed in conduit; but, if it is, boundary seals are to be installed per Section 501.15(D)(2) in Division 1. For Division 2 Section 501.15(E)(3) applies.
The MC-HL is not installed in conduit. From all l can tell in 501.15, it states that the cable shall be sealed with a "listed fitting". I guess it boils down to whether an EYS is considered a listed fitting for use with the MC-HL cable.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Well, technically, an EYS, can be used but, “[t]ype MC-HL cable with a gas/vaportight continuous corrugated metallic sheath and an overall jacket of suitable polymeric material, ... shall be sealed with a listed fitting after the jacket and any other covering have been removed so that the sealing compound can surround each individual insulated conductor to minimize the passage of gases and vapors,” can require some pretty delicate surgery. Since a TMCX was designed to do just that, why use an EYS?
The TMCX is 3x the price and has a 2-3 week lead time. EYS are on our the shelf. We probably have a need for a quantity of 30.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Of course, you have to do the economic justification. But what are your labor costs? You will find it takes far more time and effort to properly seal an MC-HL with an EYS consistently. See 501.15(C). There must be no leakage paths in the sealing compound between the jacket, armor, and individual conductors.
Sure you can install an EYS directly to the device, perhaps with a union in between, but let's think about this for a minute.
- You will need a fitting to connect the MC-HL to the EYS, probably a TMC3 since a TMC is not listed for MC-HL.
- Your EYS can not be more than 25% filled, so you will likely need to oversize it or purchase an EYSX for 40% fill.
- Why not just get the TMCX fitting and do what 2 fittings (EYS + TMC3) can do? I have a feeling the EYS(X) + TMC3 will cost more than just a TMCX.
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