R25S02

R25S02

$516.00

28V Alternator Controller, Type B
Call/Email Us For Special Pricing!

SKU: ZA000E.

Product Description

28V Alternator Controller Unit (ACU)

What’s included:

  • Installation Drawing
  • CTA7 for Cessna Installations
  • STC Certificate
  • Warranty Card
  • Product Eligibility Catalog (PEC)
  • Troubleshooting Notes
  • Instructions For Continued Airworthiness Maintenance (ICA)

Product Features:

Voltage Regulation, IC Sense reference

The Voltage Regulator keeps the bus voltage constant by increasing the current to the alternator’s field with a system load increase, decreasing it with a load decrease.

Field-to-Ground Fault Protection (GFP)

If the alternator’s field become shorted to ground, the GFP will deactivate the Voltage Regulator, and switch on the unit’s Red TSL, and the LVI light on the instrument panel.

Built-In Alternator Out Indication / Low Voltage Sensor (LVI)

The unit has a true Low Voltage Sense and Indication as opposed to the current Cessna Aircraft setup. The LVI will illuminate (turn on) under these conditions:

  • Bus voltage drops below the Low Voltage level
  • Over Voltage Protection Trip
  • Field-to-Ground Short Fault Protection Activated
  • Open alternator field (internal) or broken field wire
  • Loss of power to the ACU

Battery Off-Line Failure Regulation (BOLR)

The design of the ACU allows it to excite the field of a rotating alternator (with a minimum residual voltage) and regulate the bus voltage with the battery off-line. This allows the system to carry electrical load if the battery fails or the battery relay fails (open).

Trouble-Shooting Light (TSL)

TSL: RED with the Bat & Alt switches on means there is an internal or external ground short in the alternator field circuit.

TSL: GREEN with the engine running, means there is power coming out of the ACU.

TSL: GREEN with a bus voltage of  28.3V to 28.8V indicates a system that is operating correctly.

TSL: GREEN with a sustained bus voltage of 20V to 25.6V means current is flowing from the ACU, but the alternator field or field wire to it is open.

TSL: OFF with the Master switch on and no power to the ACU (red wire), means that one power input device (like switch, circuit breaker, or wiring) is open.

TSL: OFF with the Master switch on and power to the ACU (red wire), means the ACU is damaged.

Other Features:

  • Voltage Regulation (VR), IC Sense Reference
  • Increased Regulator life. Reduced panel lights flicker
  • Protects against grounded Alternator field
  • ACU controls & keeps the Alternator on-line if the Battery fails
  • Protects system loads against overexcited Alternator
  • Reduce trouble-shooting time, Cost-Saving Solution!

Additional Information

Weight .3 lbs
Model Number
Voltage Reg. (VR)
Max Field Current
Over Voltage Trip
Low Voltage Trip (LVI)
Approval Type
Document Approval
Approved Aircraft
Aircraft Eligibility
OEM PN: (Cessna)
OEM PN (Electrodelta)
OEM PN: (PFT)
Schematic Diagram

Troubleshooting

Troubleshooting

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

Cross Reference

Click the links below to download info in .pdf format.

Voltage Regulators for Alternator Systems

14V Alternator Controller Units (ACU) Cross Reference PDF Requires Acrobat Reader

28V Alternator Controller Units (ACU) Cross Reference PDF Requires Acrobat Reader

Single Engine Voltage Regulators for Generators 12A - 50A

14V Single Engine Generator Controller Units (GCU) Cross Reference PDF Requires Acrobat Reader

Twin Engine Voltage Regulators for Generators 35A - 50A

14V Twin Engine Generator Controllers Units (GCU) Cross Reference PDF Requires Acrobat Reader

28V Twin Engine Generator Controller Units (GCU) Cross Reference PDF Requires Acrobat Reader

Over-Voltage Protection Sensors/Relays For Alternator Systems

16V Over-Voltage Relays/Sensors (OVS/OVR) Cross Reference PDF Requires Acrobat Reader

32V Over-Voltage Relays/Sensors (OVS/OVR) Cross Reference PDF Requires Acrobat Reader

Equalizer (EQ) or Parallel Relay for Twin Engine Generator Systems

14V Twin Engine EQ Parallel Relay Cross Reference PDF Requires Acrobat Reader

28V Twin Engine EQ Parallel Relay Cross Reference PDF Requires Acrobat Reader

FAQ

Click the links below to download the .pdf

Connectors

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