Measurements GCU800 measures the electrical parameters of the generator-set 10 times per second.___ The measurements are true RMS and 0.5% accurate. GCU800 averages the incoming measurements and updates the display (LCD) approximately onceper second. GCU800 measures all the electrical parameters of three phase generators, see table 1. One phase of the mains (or the generator bus) that serves as a reference for the built-in synchronizer is also measured, see table 2. The ¡°synchroscope¡± measurements, see table 3, show the difference between the generator parameters and the parameters of the reference phase. Table 4 shows the engine related measurements. Single lead resistive senders, the common automotive type, can also be used as GCU800 effectively cancels the battery ground noise. GCU800 has three 4-digit counters that record the system¡¯s activity, see table 5. Like the kW-Hour and theHours-Run, the value of these counters is preserved while GCU800¡¯s DC supply is switched off. The counters are protected by two passwords from user tampering. Protection The generator protective functions (table 6) Parameter Transducer Table 1 Generator measurements Volt Generator Phase U none Volt Generator Phase V none Volt Generator Phase W none Volt Generator Phasen U-V none Volt Generator Phasen V-W none Volt Generator Phasen W-U none Amp Generator Phase U CT ../5A Amp Generator Phase V CT ../5A Amp Generator Phase W CT../5A Frequency Generator none kW Generator Phase U none kW Generator Phase V none kW Generator Phase W none kW Total all phases none kVA Generator Phase U none kVA Generator Phase V none kVA Generator Phase W none kVA Total all phases none kVAr Generator Phase U none kVAr Generator Phase V none kVAr Generator Phase W none kVAr Total all phases none kWh-counter none Power Factor Gen.Phase U none Power Factor Gen.Phase V none Power Factor Gen.Phase W none % THD Gen. Phase U none % THD Gen. Phase V none % THD Gen. Phase W none 2 and the engine protective functions (table 7) are based on the measurement system. All these functions have user adjustable trip-points and time-delays. Engine Management GCU800 disposes of a total of 11 auxiliary relays 380V~/10A of which 3 relays are built into the microprocessor and 8 relays are part of the auxiliary board IOB (Input/Output board). Table 8 contains a list of the protection devices of which some relays have optional functions.