How many Generator Control Units (GCU) are there on the CRJ-550, and how are they distributed?

How many Generator Control Units (GCU) are there on the CRJ-550, and how are they distributed?

• A. 3 Total; 2 for the IDGs, 1 for the APU
• B. 2 Total; 1 for IDG, 1 for APU
• C. 4 Total; 2 for the IDGs, 2 for the APU
• D. 3 Total; 1 for the IDG, 2 for the APU

Answer: (A)

Generator Control Units map one-to-one with generators, providing independent monitoring and protection for each power source. The CRJ-550 has two engine-driven generators (IDGs) and one APU generator, so there are three GCUs in total: two dedicated to the IDGs and one dedicated to the APU. This arrangement allows each generator to be monitored for voltage, frequency, current, and fault conditions while supporting proper load sharing and automatic protection of the electrical system.

Generator Control Units map one-to-one with generators, providing independent monitoring and protection for each power source. The CRJ-550 has two engine-driven generators (IDGs) and one APU generator, so there are three GCUs in total: two dedicated to the IDGs and one dedicated to the APU. This arrangement allows each generator to be monitored for voltage, frequency, current, and fault conditions while supporting proper load sharing and automatic protection of the electrical system.