28V, 50A ME GCU, Type A (Auto-Parallel)

SKU: ZG0002K.
Category: .

Product Description

28V 50A Twin Engine Generator Controller: Generator System Voltage Regulator

What’s included:

  • Installation Drawing
  • STC Certificate
  • Warranty Card
  • Product Eligibility Catalog (PEC)
  • Troubleshooting Notes
  • Instructions For Continued Airworthiness Maintenance (ICA)

Product Features:

Voltage Regulation, IC Sense Referenced

The Voltage Regulator (VR) controls the Generator’s field to keep the aircraft electrical system voltage at a specific level. This controller has a “Type A” regulator which excites the field of the alternator by providing controlled ground to one side of the field (F), with the other side internally connected to the armature.

Built-In Parallel(EQ) Relay (Automatic Parallel)

The Parallel or EQ function allows two generators used on twin engine aircraft to share electrical loads equally between them via the EQ circuit. The G2XXEN requires an external EQ relay while the G2XXKN has it built into the GCU.

Electronic Controlled Generator Build-up / Automatic Field Flashing

The Generator Build-up function allows the rotating generator to build-up its output from a low residual voltage to the system’s voltage regulation point.

Electronics Field Controller/Switching

The VR electronics switch turns the field current on/off so fast (several times a second) that the output voltage of the generator stays at the VR set point. When the generator’s output voltage exceeds the VR set point, the switch opens, current flow stops, and the generator’s output decreases.

Current Limit, IC Sensed & Controlled

The Current Limiter (CL) controls the maximum output current the generator can produce. It turn off the field excitation when the output current exceed the CL set point (determined by the generator’s current rating). It allows normal field excitation when the generator output is below the GCU CL set point.

Reverse Current Protection

The Reverse Current (RC) Protection circuit blocks the battery current from going back to the generator. It allows current to flow only from the generator to the battery and system.

GCU induced Over Voltage (OV) Protected

The GCU’s design will cause the field current path (between the field and ground) to open if the field control device becomes internally ground shorted. This means that the GCU will not induce Over-Voltage (OV) problem into the system. The GCU does not protect the system against externally induced OV faults.

Trouble-Shooting Lights on Unit

The on-unit system Trouble-Shooting Lights, TSL, identify how the system is operating and, helps with system testing and troubleshooting. The lights indicate Generator Off/On-line (GO, GREEN), Voltage Regulation (VR, GREEN), Current Limit (CL, RED), and Parallel (EQ, or Load sharing, GREEN).

Other Features:

  • Footprint Compatible to Delco-Remy’s VR
  • Increase Regulator Life
  • Not Temperature Sensitive
  • Prevents Regulator cycling at low RPM
  • Eliminate Regulator Noise
  • More Precise Current Limit
  • Prevents Battery Current Flowing to the Generator
  • GCU will not cause OV fault in the system
  • Reduce Trouble-Shooting Time

Additional Information

Weight2 lbs
Dimensions5.80 × 3.00 × 2.59 in
Model Number


Voltage Reg. (VR)

28.2V ± 0.4V

Max Field Current


Approval Type

FAA-STC Approved

Document Approval

FAA Form 337 Required

OEM PN(Delco-Remy)


OEM PN (Electrodelta)


OEM PN: (Cessna)


Approved Aircraft

CESSNA: 310, 310B, 310C, 310D, 310E, 310F, 310G, 310H, 310I, 310J, 310K, 320, 320A, 320B, 320-1

Aero Commander

500, 500A, 500B

Beech (Beechcraft)

95, B95, B95A, D95A, E95; 95-55, -A55, -B55, -B55A, -C55, -C55A, D55, D55A, E55, E55A


PA-23-150, PA-23-160, PA-23-235, PA-23-250


Product SupportPDF Requires Acrobat Reader

Warranty Policy

Click the links below to download warranty policy in .pdf format.

Warranty Policy (New Manufactured) PDF Requires Acrobat Reader

Warranty Policy (Recertified) PDF Requires Acrobat Reader

G250KN - Zeftronics


Click the links below to download the .pdf


Product Connector FAQ PDF Requires Acrobat Reader

General Product

GCU Cross Reference (Coming Soon)

ACU Cross Reference (Coming Soon)

OVR, OVS, Cross Reference (Coming Soon)

How To

How To Read the Cross Reference Chart FAQ (ACU) PDF Requires Acrobat Reader

How To Read the Cross Reference Chart FAQ (GCU) PDF Requires Acrobat Reader