That article is dealing with how the power system are wired:
The primary concern of this alert is to ensure electrical protection devices such as SPDs operate correctly with the manner in which the 120 volt receptacle circuitry onboard the vessel is wired. Receptacle circuitry may be wired in Delta or WYE configurations. Using a voltmeter, a marine electrical professional will note that a Delta wired circuit will read the voltage across the terminals as shown in the image on the right. The Delta configuration has two hot leads one at +/-60 VAC, the other at +/- 60 VAC, simultaneously to provide the 120 VAC potential. Here lies the problem with inexpensive and older SPDs that only disconnect one “hot” terminal lead. The other “hot” terminal remains hot if the circuit breaker supplying the receptacle and SPD does not trip.
A marine electrical professional using a voltmeter on a WYE wired circuit will read voltage across the terminals as shown in the image on the left. For a WYE configuration 120 VAC is established between the hot terminal and the neutral terminal and the hot terminal and the ground terminal of the receptacle.
For my MPP Solar SCC/INVERTER, the Neutral is connected to ground via Ground relay so Neutral to Ground is 0VAC thus I can use my typical power strip which the circuit breaker trip and disconnect the Hot wire only.