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Chapter 9: The Charger and Electrical System 221Fi g u r e 9-10 Curtis throttle potentiometer with high pedal disable switch (note three switchcontacts at left).Fi g u r e 9-11 Curtis replacement accelerator pedal throttle potentiometer .a fault input mode that turns the controller off in the event an open potentiometer inputis detected (for example, in the case of a broken wire)—a condition that would result ina runaway—you are covered in both instances by using the Curtis controller and throttlewith high pedal disable option. Figure 9-11 shows that the throttle potentiometer wiringgoes directly to the controller inputs, with the interchangeable potentiometer leads andthe common and normally closed contacts wired as shown.Auxiliary RelaysFigure 9-12 shows these highly useful auxiliary control double-pole, double-throwrelays in both 20-amp-rated 12-volt DC (on right) and 120-volt AC coil varieties. Atypical use for the AC coil type would be as a charger interlock. Wired in series with theon-board charger, AC voltage sensed on the charger’s input terminals would immediatelydisable the battery pack output by interrupting the auxiliary battery key switch line,which, in turn, opens the main contactor. DC coil uses are limited only by yourimagination: additional safety interlocks; voltage, current, or temperature interlocks;and controlling lights, fans, and instrumentation.Terminal StripWhatever you’re doing in the electrical department, a simple terminal strip like the oneshown in Figure 9-13 makes your wiring easier and neater. Using one or more of these asconvenient tie-off points not only reduces error possibilities in first-time conversion wiring,but also makes it simpler to track down your connections later if needed. Of course, it’sonly as valuable as your hand-drawn sketch of what function is on which terminal.