Is it permissible to use the entry plate holes for tower light power, building ground, and control cables?

• A. Yes, it is allowed for all cables.
• B. Yes, but only with manufacturer approval.
• C. No, it is not permissible.
• D. Only for some cable types.

Answer: (C)

The idea being tested is keeping different electrical paths physically separate at entry points to prevent interference and safety issues. Sharing entry plate holes for tower light power, the building grounding conductor, and control cables mixes power, grounding, and signaling in one opening. That can create ground loops, EMI, arcing paths, and compromises to enclosure integrity and protective devices. These risks undermine reliability and safety, so such a mixed use isn’t allowed. Each service type should have its own appropriate entry path or be routed per the manufacturer’s guidelines and site standards, with proper strain relief and sealing.