Cable Gland Terminations Bonding

[ThePunisher]

This may look like a stupid question but I will fire it anyways and I appreciate everyone's patience.

At one location, we have a 4.16 kV cable buses, from transformer secondary to switchgear, with sheathed single core power cables in them. We used metal cable glands (connectors) to terminate on the top of the switchgear. We installed metal bushings with ground lugs on the connectors and bonded them, "daisy-chained" to the switchgear ground bus.

However, on another location, the single cables from the transformer to the switchgear where connected to the top of the switchgear using cable glands but with non-metallic bushings. Therefore we are not able to bond these bushings to the switchgear ground bus. Is this acceptable? If not, we are thinking of installing a split-type grounding bushings or grounding inserts (looked like a washer with a ground lug)

In both installations, power cable sheaths are bonded to the switchgear ground bus. On a side note, the cable sheaths at the switchgear terminations were bonded together and passed back through the zero sequence CT before it got terminated to the switchgear ground bus.

Thank you for your inputs.

Regards

 

[7anoter4]

NEC 2017 Art.250.4 General Requirements for Grounding and Bonding.
(3) Bonding of Electrical Equipment. Normally non–currentcarrying
conductive materials enclosing electrical conductors
or equipment, or forming part of such equipment, shall be
connected together and to the electrical supply source in a
manner that establishes an effective ground-fault current path.
Nonconductive parts of equipment should not be grounded