Manual Transfer Switches | Ronk 3 Phase | AP Electric Ronk 3 Phase Manual Transfer Switches. We offer a wide variety of Ronk Manual Transfer Switches. As with any transfer switch there are a few things you need to look into before making a purchase. The three varieties of Ronk switches that we offer are non-service entrance rated, service entrance rated (SE Rated) and Non-UL. 200 Amp Three Phase Manual Transfer Switches We offer 200 amp three phase manual transfer switches from Asco, Ronk, Thomson, and Winco. Ronk and Winco models are mechanically operated. Asco and Thomson models are electrically operated. Asco transfer switches include a microprocessor controller.