Which of the following is NOT considered a type of ground-fault protection of equipment?

A ground detection system sensor connected to each ungrounded service entrance conductor is indeed not considered a type of ground-fault protection for equipment. Ground-fault protection is designed to detect faults that may cause electric shock or equipment damage by measuring the difference in the current flowing in and out of the system.

The use of ground detection systems primarily serves to indicate the presence of a ground fault and is not in itself a protective measure to disconnect equipment under fault conditions.

On the other hand, the other options listed involve configurations that actively monitor and respond to ground faults. For instance, the neutral ground strap-type (CT around a main bonding jumper) and the zero-sequence-type configurations use current transformers (CTs) to monitor electrical imbalances that indicate a ground fault. These devices can trip a circuit breaker or take other protective actions in the event of a fault, effectively protecting both personnel and equipment from potential hazards.