Complete Selection Guide for Sealcon Romex Cord Grips

Complete Selection Guide for Sealcon Romex Cord Grips

Choose the right fitting for flat cable and avoid the costly mistakes that cause seal failure, UV cracking, or rejected installations.

⚠ Common installation error

Romex inserts are not interchangeable with ribbon or zip cable. Using the wrong cable type voids the liquid-tight rating and can create a shock or fire hazard. See the compatibility table below before ordering.

1. What Sealcon Romex cord grips do

Sealcon's strain relief fittings secure flat non-metallic (NM/Romex) cable where it enters an enclosure. These cord grips prevent pull-out and maintain a liquid-tight seal. The fitting body is identical to Sealcon's standard cable glands; only the insert differs.

Cable types supported

Romex NM & ASI-BUS

Thread options

Metric · NPT · PG

Insert compatibility

Interchangeable with Sealcon dome-top series

Compliance

RoHS · Deca BDE

2. Gray vs. black nylon: which material do you need?

Gray nylon

  • Indoor & protected enclosures
  • Resistant to: salt water, alcohol, weak acids, mineral & vegetable oils
  • Standard industrial environments

Black nylon

Recommended outdoor
  • All gray nylon resistance, plus:
  • UV & ozone stable so it won't dry out or crack
  • Direct burial with cable
  • Damp and wet locations (per Romex NM-B ratings)

3. Cable compatibility at a glance

Cable type Compatible? Notes
Romex NM Yes Flat NM cable from Southwire or equivalent. Multiple sizes available.
ASI-BUS Yes Industrial networking cable. Two-color variants (high/low power). Requires correct insert size.
Ribbon cable No Too wide and thin. Insert cannot create a seal.
Zip / SPT cable No Designed to be split. Liquid-tight seal is not achievable.

4. How to select the right size in 3 steps

  1. Measure your cable's flat width and thickness. The best way to tell whether the insert will fit is to measure your cable. There should be less than 1mm of difference between the cable dimensions and the insert slot dimensions.
  2. Match your conduit or enclosure thread type. Choose metric (most common internationally), NPT (North American standard), or PG (European standard).
  3. Select your environment. Indoor or dry location → gray nylon. Outdoor, UV-exposed, damp, or direct-burial → black nylon. Both resist salt water, weak acids, alcohol, and oils.

Pro tip: Sealcon inserts are sold separately and are interchangeable for similar size dome top cable glands. Check the insert product description to find out what sizes it is compatible with. Stock spare inserts if you work with multiple cable sizes, it's easier than ordering a full fitting each time.

5. Troubleshooting & common problems

Fitting leaks after installation

Check that the correct insert size is used. The insert must fully contact all flat surfaces of the cable. Make sure the locknut isn't overtightened. Overtightening the locknut can distort the insert.

Insert won't seat flat in the body

Romex inserts only fit dome-top cord grip bodies. Confirm the body style before ordering. Standard round-cable inserts are not compatible with flat cable.

Cracking or brittleness outdoors

Gray nylon is not UV stabilized. Replace with black nylon equivalent. Inspect all outdoor gray nylon fittings annually in high-UV environments.

ASI-BUS cable not sealing correctly

ASI-BUS cables have a different cross-section than Romex. Verify you have the ASI-BUS specific insert, not the Romex flat-cable insert. The two-color cable coding (high/low power) does not affect fitting selection.

Pre-order checklist

✓ Cable is Romex NM or ASI-BUS (not ribbon/zip)
✓ Cable dimensions identified
✓ Thread type confirmed: metric / NPT / PG
✓ Environment: indoor (gray) or outdoor/UV/burial (black)
✓ Dome-top body style confirmed (required for flat inserts)
✓ Locking nut and seal/O-ring included